My Home Solar Panels

Frequently Asked Questions

1. QUESTION:
   Charging two car Batteries togather with one charger, would Parallel Conections work?
   Hi, I have two car batteries and I want to charge it with one 12 Amp Battery Charger. besides charging them one by one, Can I connect the charger to batteries in parallel circuit so It would charge 6 amp each and take twice as much?

   would it work and still charge Okay?

   Thanks

   • ANSWER:
     sure,,,,,,,,,,a pararell connection is still a 12 volt hookup.
     Auto shops hook a couple of batteries up to a charger all the time.

2. QUESTION:
   Charging car batteries vs. the Jump Start?
   I know when you're jump starting, you really should connect the negative to another ground position besides the battery. Should you do the same when simply charging a passanger car or a small boat battery with a battery charger? Or is it not as important. (personal bet)

   • ANSWER:
     When charging you should put both wires on the batt. Only when jump STARTING should you place the neg on a ground.

3. QUESTION:
   What are some precautions when charging car batteries?

   • ANSWER:
     Hope the following helps. I got it from the web.

     Remember that when you're charging car batteries, hydrogen, a highly flammable and even explosive gas, is released from the reaction of the current and the plates that are immersed in sulfuric acid. Do not light anything and avoid creating sparks near a charging battery. You must also keep the batteries well ventilated while charging to disperse the hydrogen gas.

     Before charging car batteries, ensure that the water level reached the maximum desired level. Add distilled water into the battery if you notice that the water is lacking even very slightly. A well-watered lead-acid car battery can purge the hydrogen gas more efficiently than those that lack water. The accumulation of hydrogen gas to dangerous level can very well be prevented if your batteries are well watered before charging - or even during regular use for that matter.

     Another important point to remember when charging car batteries is to never overcharge it. An automatic charger that stops charging after it has detected the threshold level, though, can help you on this. But if this is not available, make sure that you follow your charger as well as your battery's manual for charging to avoid overcharging your battery. Overcharging your lead-acid battery can not only shorten your battery's life, but it can be a recipe for disaster also.

     While your battery is charging, stay away from it as possible. Warn other people, especially the young children, to stay away from the garage because you're charging your car battery. You must also place the charger as far away from the battery as possible. And remember that you must never place you face over your battery in near proximity because there are instances that a cap could blow due to the gas pressure inside it. Wear protective goggles all the time.

     While you cannot avoid charging car batteries, you can, however, avoid the accidents that can occur while doing it. Exercise extra precaution all the time to avoid injuries from charging car batteries.

4. QUESTION:
   Ventilation Requirements for Charging Car Batteries.?
   I've always charged car batteries in a garage or outside, currently it's pouring rain and I have no garage. Is it safe to charge a car battery (60ca) with an automatic charger (at 2A) in a smallish, unfinished basement (300 sq ft) where there is a running furnace?
   It is a sealed, maintenance free type

   • ANSWER:
     Yes ,go ahead,most batteries are of the permanently seled type and you can charge them in a closet

5. QUESTION:
   Solar Charge Car Batteries - for Energy Use How Do I proceed?
   I have a small building for use as a Studio. I want to power as cheaply as possible. I intend to get a solar panel and charge a bank of perhaps four car batteries. I would like to know how I can charge four care batteries with a solar panel - How do I hook them up? What's the cheapest lowest Watt Output Solar Panel I can use to charge them?

   ALSO - using a modern Battery charger (for cloudy days can I charge four car batteries at one time as well? How do I connect them?

   • ANSWER:
     Sorry ! But here is the sad truth. By the time you buy batteries, buy a solar panel, buy a battery charger, buy twelve volt bulbs, you are going to have a large investment.
     It will take years before you realize a savings over buying electricity from the power company
     However if the building is in a remote area ,where commercial power is not available, you can purchase solar battery chargers from your nearby farm supply store or from J.C. Whitney out of Chicago,Illinois. The wiring schematics will come with the charger. It is easy.Good luck with the project.

6. QUESTION:
   How does the charging car battery works with engine on?
   Is it enough to keep the engine running on regular bases or does the car have to move for the battery to charge? I am asking becouse mine could do with a charge top up but I have been on medication that makes me drowsy so there is no way I can drive to do this, I can seat n the car for a while tho if that is enough?
   so...who is putting thumbs down for most the answers?

   • ANSWER:
     lol diesel, i assume you are describing an alternator, not a battery. As a battery is not belt driven nor has any moving parts lol.

     the alternator produces a mechanically induced electrical current, a magnet spins inside a copper coil causing intermittent posotive and negative electricity. This is charging the battery as the crank turns. As someone already mentioned, it is a bit better to drive the car to prevent other things from seizing and to lift the revs a bit. But you shouldnt need to worry unless the car is being stored for over months tho

7. QUESTION:
   Will alternator charging 12V battery attached to 220VAC inverter connected to in-car 144V charger charge EV?
   Such an arrangement presupposes that the alternator can be powered to rotate separately. Will this work to charge the EV car batteries while the car is running in order to do away with several hours of at-home charging?

   • ANSWER:
     Yes, it will work, but at a significantly low efficiency. Every time you convert the voltage, you are losing energy as heat. You will also want to upgrade the alternator, as most modern cars only come equipped with alternators capable of sustaining the electronics placed by the manufacturer.

     You might look at a solution involving only a single voltage change, from 12 to 144. No since in inverting and then rectifieing the power, when you can just invert it once and be done with the whole mess.

8. QUESTION:
   Is it normal for a car battery to make a sizzle type noise while charging and after charging?
   i have my deep cycle car battery charging on a 8amp charger not connected to my car. It's up to 4amps on the charger power meter, and i just noticed it's sizzling? I unplugged it, but its still sizzling, any clue? The charger is supposed to shut off once the battery is fully charged. And is it safe to attach the battery to my car now, or should i wait until its done making noise?

   • ANSWER:
     deep cycle car battery? Odd application for one but anyhow if it's making noise that's not a good sign. If it's a sealed battery there isn't much you can do. If it's not, let it stop making noise then check the water level inside it might just be low and you're hearing boiling. Either way I wouldn't hook it up while it's still sizzling.

     You can check to see what it shows for voltage with a multimeter hopefully it shows 12-13volts if it reads out under 10 the battery is probably shot and you'll need a new one.

9. QUESTION:
   Will I drain my car battery charging my mobile phone?
   Next week I'm going away for 5 days, and in that time the only access I'll have to electricity will be my car. When my mobile phone runs out of battery, I plan on charging it using the cigarette lighter slot in my car. Will that drain the battery?

   I'm well aware that it won't drain the battery when the car is driving, but my car will be stationary whilst I'm charging. Does that change anything?

   Thanks.

   • ANSWER:
     Defiantly won't drain your battery, I do this all the time with other things too like my sat nav. Some cars (such as a Ford Focus) you can charge without the key in, others you should work with just the key in the Accessory (ACC) position. In any case you defiantly won't burn out a coil on a modern car as someone suggested, as a qualified mechanic, I would have had to replaced 1,000 coils by now for leaving the key in the "ON" position while carrying out diagnostics, etc.

10. QUESTION:
    Why is it important to connect negative terminal away from car battery when charging?
    I have read on a website that when charging your car battery, whether inside or outside of the car, you should connect the negative (black) clip away from the battery by using a jumper cable when the battery is not connected to the car or by connecting the negative clip to a piece of solid steel connected to the frame if the battery is indeed connected to the car.

    Why is this?

    • ANSWER:
      The idea is that the last connection you make should be away from the battery because that's the one that will spark, and there could possibly be some hydrogen gas near the battery that could cause an explosion.
      The main thing that the "experts" get wrong when you're jump starting is where to connect it. You shouldn't connect it to the frame or chassis, because you'd be pulling several hundred amps of starting current through the engine/chassis ground connection, which isn't made to handle it. You should always make that last connection to the engine block. It doesn't matter much when just charging.

11. QUESTION:
    Does charging batteries from your car ruin your batteries?
    If I use one of those inverters to convert 12v to 110v in my car does it ruin my Lithium Ion battery in my laptop? It seems like it used to last longer when it was charged in my house rather than in my car.

    • ANSWER:
      I'd never charge a laptop in my car. A house outlet is much more reliable if anything else. You are almost guaranteed to get a good charge in a home. Charging it in a vehicle is way to 'iffy'.

12. QUESTION:
    Is there a problem with charging a car battery with the battery outside of the car?
    I want to remove the battery from the car and charge it on the ground so i dont have to stay on the main rd charging it. The battery is completely dead, it is a brand new battery but it has been sitting about 6 months. How long do you think it would take for it to get a charge to start the car?

    • ANSWER:
      Charging the battery off the car is a good idea, probably better than charging on the car.
      The best way to charge it would be with a trickle charger but, this could take a long time. A fast charger could only take an hour to put enough charge in it to enable the car to be started. Charging times will depend on your charger output.

13. QUESTION:
    Could you charge a car battery with 8 AA batteries?
    i've looked online, and a car battery uses 12v and a AA battery is 1.5v, would 8 of them charge the battery enough to at least start the car?

    • ANSWER:
      hahahah good question. I think you would need at least 16 AA.

14. QUESTION:
    Why us my car battery turned white after charging for a while?
    Ii was charging my car battery that was in my car not used for 1 year. So after being charged for a while the sides got bigger and there is this white staff on it like snow. What is going on?

    • ANSWER:
      Ya cooked it. That white stuff is highly corrosive [acid] and it is also giving off hydrogen gas, ridiculously explosive. Put it out in the yard, let it gass then dispose of it. Right now it is essentially a bomb.

15. QUESTION:
    Doesn't it use more energy to charge batteries for a car than to use gasoline to run the car?
    It seems like using coal or gas to run generators and push the energy miles through wires and into car batteries would sacrifice a lot of the initial fuel as it is lost to heat along the way and right through the charging process. Has the math been done to prove this one way or the other?

    • ANSWER:
      First, electrical transmission lines are low resistance, so very little energy is wasted sending electricity to your house. Probably less than 1%.

      Second, gasoline engines are fairly inefficient. A good one probably wastes about 80% of the energy in the form of heat.

      Electric motors, on the other hand, are more efficient than gasoline engines.

      In a real world example, worth of electricity will take a modified Prius (one that runs more from batteries) as far as a gallon of gasoline, which is a savings.

      Plus, people would probably recharge cars more at night, when electricity use is usually low.

16. QUESTION:
    Has any one had a problem after charging a jumpstart battery in their car?
    After I used tryed to charge my jump start battery in my car using a 12v plug, the car no longer charges my car battery.
    Did my alternator died out?
    When I used the battery on another car it worked fine.

    Is it bad for a car to charge a jump start battery while driving?
    ** I didn't ahve a charger to charge it in my house so i tryed in the car.
    I also need help findign this on forums

    • ANSWER:
      I don't quite understand what you mean by starting your car with a 12 volt plug. Generally speaking battery chargers are rated by regulated amps not volts. If you jump started your car with another 12 V source such as another battery no damage should have have been done to your car's alternator.
      The only thing you can do now is test your alternator with the car running with a volt meter across the battery terminals. It should read a minimum of 13.5-14.0 volts. If not, a new or rebuilt alternator is in order.

17. QUESTION:
    fiat 500 remote control car battery charging problem?
    I bought a FIAT 500 remote control car which is a baby ride. When I first charge the battery with the provided charger, the battery doesn't get warm at all after few hours of charging, is it normal becoz manual said the battery would get warm during charging.

    • ANSWER:
      maybe the fault in the battery.....you should try changing your battery......

18. QUESTION:
    When charging a car battery (trickle charger), do you need to disconnect the battery from the car?
    I'd rather not have to disconnect the battery from the car, but will it charge if I don't?

    • ANSWER:
      Yes, it will charge just fine.

19. QUESTION:
    I need help right away.Do you live a car battery charging indoors?
    Hi. My dad puts the car battery to re-charge everyday just to start the car. What I was wondering if it's safe to leave the battery charging inside the house? By the way he takes of the caps on the top to recharge it. Please help me.

    • ANSWER:
      No, it is not advisable to charge your battery in the house. Do you live in the Arctic Circle?

20. QUESTION:
    what 2 gases are made by car batteries when charging?

    • ANSWER:
      I know one of them is hydrogen. The other one has to be some product of oxygen, lead, hydrogen and/or sulfur.

21. QUESTION:
    Would a wind generator trickle charge a couple of car batteries in 14 hours?
    I'm just trying to get an idea of how long it takes a wind turbine to charge batteries with regular win, could you just provide some examples?

    • ANSWER:
      Hey Joesh, wind turbines come in all different sizes, but your biggest variable here is the rate at which those batteries will accept a charge. Typical car batteries will have a capacity of around 60 amp hours. If you had a 60 amp charger, or turbine, in theory you can completely charge that battery in one hour, but you can never get power into a battery that fast without damaging it. A good rule of thumb is not to charge your battery in less than 5 hours if it is completely discharged. A couple car batteries might hold 120 amp hours, which means anything that puts out more than 30 amps is oversized. You can take a larger than needed turbine and use a charge controller to keep from charging the batteries too fast, but that is like using an indy 500 race car to haul a camping trailer, most of the capability of your turbine would be wasted. The best thing is to get a turbine that is just big enough, or maybe a little undersized, to do the job. For 100 to 150 amp hours of 12 volt batteries, I would suggest something in the 200 to 300 watt range, like a Southwest Windpower Air 303. They cost just a few hundred dollars, are designed to work on a sailboat to keep the boat batteries charged, and they have their own internal charge controller. So you just mount one on top of a 1 and 1/2 inch diameter conduit pipe, then connect the two wires from the turbine straight to the batteries. We used one for a couple years here at our remote cabin, but later upgraded to a larger World Power Technologies 900 watt unit. There are lots of other turbines on the market that can do that job for you, just remember that even the best turbine will not pan out if you do not have good wind, or a tall enough tower to get to the wind above the tree tops.

      There are some great places to learn more about this if you're interested, but I'm curious, have you considered solar? Solar panels are so much easier to use, install and wire up, and they never need maintenance, you can take my word on this, I've had both for over 11 years now. A solar panel is basically a battery charger, they deliver their rated amperage when the sun shines, no more, so in a sense they are self regulating. If you really want to get up to speed on this stuff, get a sub to Home Power Magazine, we did 12 years ago, now our home is completely powered by the wind and sun.

      If you get frustrated by all the numbers thrown around, remember that watts is voltage times amps. So a 300 watt wind turbine that runs at 12 volts will put out 25 amps at full power, 25 X 12 = 300. Solar panels are basically the same animal, but they are all usuallly set for 18 volts to charge a 12 volt battery, so a 36 watt panel will actually put out 2 amps in full sun, 36 divided by 18 volts is 2 amps. Hope this helps, take care, Rudydoo

22. QUESTION:
    Does anyone know if they still make a battery charging switch for a car with a sound system?
    Hello, About 9 years ago when I was into auto audio systems there used to be a device that you could put in your car that would act like a switch between your main battery (the one that starts and runs your car) and an auxiliary battery (something like a deep cycle battery that your sound system could pull from when demanding high amounts of power). It would monitor the two batteries and it would charge the main battery first and when the main is fully charged it would switch over and allow the alternator of the car charge the auxiliary battery. I was wondering if anyone knows if this is still around and if so what's it called and who makes it? Or if it's possible to build something like this that would be I'd also be interested in. Thanks for your time and help!

    • ANSWER:
      Is it possible you are looking for a battery isolator? This site might help

      http://www.bcae1.com/battiso.htm

23. QUESTION:
    what size/kind of solar panel would i need to keep a car battery charging?
    I'm looking to run a small stereo off of a standard car battery on a trip i will be taking next week, and was curious what kind of solar panel i could use.

    I figure i wont be able to just use of the 'top-off' solar panels for cars, but i'll probably need one that's meant for charging batteries from a semi to severely depleted state.

    Any suggestions?

    • ANSWER:
      This looks like a good one, it got high ratings!
      http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200305091_200305091
      Good luck!

24. QUESTION:
    car batteries dead batteries and charging?
    if the car battery dies and its not charged for say a week after it died will there be any damage??

    • ANSWER:
      It wont hurt the Battery to sit, just recharge it, and it doesn't hurt to sit on concrete that's a myth, the battery box is insulated, their used to be re-barb running threw concrete so when lightning would strike and run threw the re-barb it would damage the battery,
      Just re charge it and check the fluid if it has removable caps, add water if needed. if it wont hold a charge get a new battery.

25. QUESTION:
    Can I charge multiple car batteries with a charger if I connect them in parallel with jumper cables?
    Also, if i run the charger at 15 amps on 2 batteries, is that like each of them getting 7.5 amps? Thanks.

    • ANSWER:
      Yes you can connect them in parallel....... Even batterys made by the same manufacturuer will have small differences so no they will not draw the same current. I will point out that I would not set the charger at the lowest settings... If one battery is much stronger than the other you could actualy cause circulating currents between the batterys and neither would charge properly........ I also would not set them at high or 15 amps or more if you are going to charge them overnite.... You could end up gassing out the fluid/acid in the battery. If your looking for a quik charge up for a short period of time then what you have asked and suggested would be fine.... Just make sure you disconnect the second battery before you disconnect the charger (prevents the circulating current scenario)

26. QUESTION:
    What are the proper procedures for charging a car battery with a 10 amp battery charger?
    also, does it matter where I connect the ground? I've read to neg terminal and some say somewhere else on the car.

    • ANSWER:
      Disconnect the battery first, then charge , check the meter it will tell you when it's fully charged.

27. QUESTION:
    How long do I charge multiple 12v car batteries in connected series?
    My battery charger has a 2 amp, 10 amp, and 40 amp settings. I have 4 car batteries hooked up in series for my hydralics. How long do I charge them for each amp setting?

    • ANSWER:
      If you are trying to charge them while connected in series you will need a 48 volt charger. Best to do is to charge them either one at a time or connected in parallel. This way you can use a regular 12 volt charger. Slow charging is always better. Try to keep the charging rate around 5 to 10 percent of the battery capacity. At this rate you should charge 15-20 hours.

28. QUESTION:
    Trickle charging a car battery that hasn't been used in six months?
    Should I trickle charge the car battery with 1.5amps and 12 volts, how long will that take?
    Or should I trickle charge the car battery with 10 amps and 12 volts how long will that take?

    • ANSWER:

29. QUESTION:
    Does charging a car battery really help?
    My car battery seemed like it was on the way out because it's 4.5 years old and the starter hesitated when I first tried to start the car after not driving it for a long time.

    So, I took it to Auto Zone and they tested my battery. The guy said it was 'weak' but didn't need to be replaced yet. He charged it for free.

    It works great now. How much longer can I expect my battery to last? Winter is coming, should I just have it replaced?

    • ANSWER:
      it definitely helps, as long as batteries dont go bad they can be recharged and still be used.

      you should try to find out why you had a weak battery to begin with, they do lose a charge while in storage. if you plan on letting it sit for a long time again, get a battery tender and you're good to go. if its only been stored for a few weeks then it might be your alternator which the auto zone dude should be able to check as well, also free. if i were you i'd have him check the alt and battery at the same time after a couple of weeks, this will tell you if you need a new battery or alternator.

      4.5 years is definitely enough from a battery, your investment has more than paid itself off. if you are tremendously worried about it just go get another battery, they aren't very expensive at all and ya might sleep easier. but i would check the alternator first just in case so you dont drain a brand new battery.

30. QUESTION:
    Charge 2 car batteries but use only 1?
    I have a fridge and few more accessories on my car that always need power. The point is I don't want them to use up all my car's battery so then even if I don't start up my car for a few days, I can still start it up. I have 2 car batteries. I wonder how to connect them together so that when my engines running, 2 batteries can be charged. And when the engine stops, the primary battery's power will not be used or loose power.

    • ANSWER:
      It's called a battery isolator and is available at any RV shop and they are relatively cheap. What this device does is allow your accessories to run off the isolated battery but it allows your alternator to charge both batteries when the engine is running.

31. QUESTION:
    I am planing to fit solar panels on my car to help charge my car batteries.... suggessions?
    I am planing to put solar panels to help lift some strain off the alternator and thus helping gas milage.

    I know solar panel's contribution would be a fraction to what alternator does but it might show in the long run. also it will keep the battery charged longer.

    I am thinking to connect directly to the battery or maybe to the lighter plug. which one is better? anything else I have to be carefull? Thanks

    • ANSWER:
      Save yourself some work...... the solar panels will help keep the battery charged if the car is stored and not run for extended periods. It won't be taking any strain off the alternator, because the engine has to turn the alternator anyway, and you wouldn't see any mileage increase. The tiny amount of current that the solar panels would provide wouldn't make a noticeable difference. Most alternators put out anywhere from 50-100 amps....... I be surprised if your solar panels managed to produce more than a trickle charger would.... about 1-2 amps.

32. QUESTION:
    how long should you leave a car battery charging for to get the maximum results?
    is 1 hour long enough or should it be even longer?

    why for this and is it not good to charge for too long?

    if so, why?

    thanks for your answers!

    • ANSWER:
      It is fully charged when all the cells are giving off gas in the same volume. The time can vary from a few minutes to many hours depending on a number of factors including the capacity of the battery, the output of the charger and the original state of charge of the battery. If all but one cell are gassing that cell is probably dead and the battery will need replacing unless it is a very large stationary battery where individual parts can be changed.

33. QUESTION:
    What if you connect the batteries improperly? I.e. you put the black on the red. What could happen to the car?
    My hubby accidentally connected the battery incorrectly when he was charging another cars battery. Now the vehicle won't turn over. What could the extent of the damages be? It was a 1997 Chevy cavalier, with a known crummy battery.

    • ANSWER:
      My condolences to your car, and you, for having a hubby that could accomplish this feat.

      Many different things could have fried, the list is too long to write. Good luck.

34. QUESTION:
    What are the dangers in charging a car battery whilst still connected?
    I wish to avoid having to reset my radio after charging

    • ANSWER:
      You are asking about the dangers right?
      we'll, obviously it produces sparks and may end up a happy holiday season.

      As a standard operating procedure:

      When charging your battery without disconnecting it from your car, you should turn your ignition key off and pull off the ignition key.

      Remove all the vent caps of your battery.

      Check your battery fluid level, top it up if below the level. You can use a mineral water or distilled water.

      Connect the charger's boosting cable to the battery terminals first before plugging your battery charger a wall socket.

      Set your charger to a low charging, never ever set it to fast charging time.

      Always check the battery and the charger, as much as possible don't leave it.

      Hope this could help.

35. QUESTION:
    Do I need to disconnect car battery prior to charging?
    I am attempting to charge my friend's car battery (it is low from the car being off for months) with a Vector 2 amp charger (AC to DC). Do I need to first disconnect the battery from the car to charge it or can I leave it connected? (Ease is more important to me than length of time it takes.) Thanks!

    • ANSWER:
      You shouldn't have to remove any cables for charging or jumping , it would be advisable to though because of the trace loads(clock,radio,computer) with a 2 amp charger.

      The big thing is you don't want any sparks

36. QUESTION:
    Any danger to slow-charging an 80% charged battery while it is inside and attached to a car?
    I have my battery charging in the car, its pretty well charged up its at 80% charged when i put the charger on it it was drawing "2 Amps" at 6Ampcharge and went to about 70% or 80% on the meter, i have it slow-charging at 2 Amps to top it off real nice. It is in the car, attached as a battery should be, it could start the car.

    Any danger in slow-charging it attached as i have it?

    • ANSWER:
      slow charging is best. make sure you have a charger that will shut off when the battery reaches full charge. continuing to charge a fully charged battery can ruin the battery and in extreme cases can be dangerous

37. QUESTION:
    When does over charging a car battery start causing permanent damage?
    and, If the battery remains to be at a cool temperature, does than mean its not being overcharged?

    • ANSWER:
      When you actually overcharge it is the answer to first part.

      Overcharging is likely to cause overheating but all batteries tend to get warmer whilst charging - ambient temperature will alter this.
      If it remains completely cool it is probably not being charged at all.
      Most modern chargers have a circuit that analyses the charge and cannot overcharge it. An overcharging alternator will ruin and could cause the battery to split as well as damaging important expensive electronics.

38. QUESTION:
    Charging a battery bank with a car alternator?
    I have a four 6 volts deep cycle battery bank arranged to output 12 volts powering a 12 volt power inverter. The inverter has its own built-in charger as the electricity comes and goes where I live. So far so good. In case there is a power failure for, say, two days. Can I use my car to charge the battery bank? I'm thinking about using jump cables. How long will it take for the alternator to fully charge the four batteries?

    • ANSWER:
      Yes and No. The alternator in your vehicle produces a max of 13.5 volts when functioning properly. A typical battery charger will produce up to 15 volts. The inverter in your charger will also produce 15 volts. Interesting enough 12V solar panels actually produce between 16 and 18 volts. The car alternator will provide charging output to the batteries but you would have to run the vehicle for a long to time to get much of a charge.

      Also, with the car alternator, you don't have any way to properly control the rate of charge. You can seriously damage your batteries if you don't charge them properly. I've messed up several during my learning curve.

      You're much better off buying a small generator and charging the batteries properly with the generator during a power outage.

      So in summary, yes, you can charge them with the jumper cables in a pinch but you won't get a full charge and you need to be extra careful and make sure to hook the cables up to the proper terminals on the battery bank.

      This should only be done in an emergency and with the understanding that you're running the risk of damaging your batteries.

      I hope this helps you,

      Patty

39. QUESTION:
    What limits the rate of charging of a car battery: the battery itself, the alternator, or something else?
    For example, if a car battery is partially drained, would it charge faster with a high output alternator? Do standard alternators already put out more current than an average battery can accept?

    Or is there some other factor that has a major influence, such as the wiring from the alternator to the battery or battery to ground?

    Assume we're talking about a normal car, without a high-power audio system installed, or any other power-hungry options/accessories.

    • ANSWER:
      It's the voltage difference between the alternator output and the battery (ie, the rest of the electrical system) that sets the charging rate.
      The alternator voltage range is determined by its design and limited at high revs by the built-in voltage regulator.
      All things being equal, the flow to the battery depends on the current demand in that moment (ie how much current is fed into the various services) and how fast the engine turns.
      Say the battery is at 12.5V and the alternator at 14.5V - it's the 2V difference that drives the charging current to the battery. How high is the charging current depends on the total resistance of the charging circuit, including the inner resistance of the battery. Suppose it's 5A. If at that moment 2A are drawn to power whatever is switched on, the charging current is reduced by 2A to 3A. When more current is drawn than charged, the regulator prevents the alternator from drawing current (acting as a motor).
      So, yes, the partially drained battery charges faster if there is no other demand for power. As the battery charges and it's voltage rises ever closer to the alternator one, the driving voltage difference reduces charging to a very low level.
      The wiring is of no consequence provided it is adequately sized and in good condition. The ground connection is very important, especially at the far end of the circuit (lights), less at the battery.

40. QUESTION:
    Can an autorepair shop like autozone, that charges car batteries, charge my SLA battery?
    SLA is sealed lead acid, and I was wondering if anyone who's had experience with car chargers knows if it matters that it's a sealed version of the lead acid battery or not. Here is a link to the type of battery I need recharged(and yes, these batteries are rechargeable):

    http://www.yuasabatteries.com/pdfs/NP_7_12_DataSheet.pdf

    • ANSWER:
      Probably not. A typical car battery has 400 amp hour capacity and gets charged at about a 12 amp rate. Your battery has a 7 amp hour rating. It might explode if you used a regular car battery charger on it.

41. QUESTION:
    What is the difference in Trickle-Charging a Car Battery at 2 Amps, 4 Amps, and 6 Amps?
    I am trying to rotate the three different Amperages. My Charger just indicated "75" Full on 6 Amps, so i switched it to 2 Amp Charge, what are the differences and benefits for the battery at these charge rates?

    • ANSWER:
      speed is the difference. always and without exception, slower is better. but for time, you can use the higher settings. the charger is actually causing a reaction in the battery, making the sulfur jump off the lead plates into the acid. slower charging allows a more thorough release of the sulfur. your battery is close to a full charge hence the full reading on the higher setting. but as you found, on the lower setting it can now get topped off. no need to rotate the settings, just use the slowest that you have time for. there is a lot of miss information out there on car batteries, because most people do not understand how they actually work.

42. QUESTION:
    When charging a car battery, why can we no longer connect to the negative terminal of the battery?
    I'm having a real hard time finding any unpainted metal that the cable can reach. We used to just connect both cables to the battery.......

    • ANSWER:
      In theory, you can connect to the negative terminal of the battery.

      The reason that it is not advised is because during the battery charging process, Hydrogen gas is released.

      Hydrogen gas is very flammable, and typically when you connect/remove the connectors to the battery, you will get a spark. This can ignite the hydrogen gases that have accumulated during the charging process.

      If you do the charging of the battery in a well ventilated area, then theoretically you should be alright connecting your charger to the negative terminal. It doesn't take a lot of time to accumulate the hydrogen gas though.

43. QUESTION:
    Can a 18W solar panel charge two car batteries? I am planning going solar, thanks?
    And also, can I connect the 18watt solar panel to a 800 watt power inverter?
    I wanna use a car battery to charge home stuffs. I wanna connect the Inverter, the batteries and the solar panel. I just wanna know in a sunny day will it charge the whole battery? I just want the inverter to convert the power from the battery.

    • ANSWER:
      In short you need to read ratings and ask manufactures. There are lots of ways to figure power using current, voltage and resistance. The voltage has to be around 14 to 15 volts to charge a 12 volt battery and if you only have, say, less than one amp available, it could take days/weeks/more to charge the batteries. On the surface without knowing details, it doesn't sound feasible and if it is, functionality should be considered, if the battery will be discharged in four hours and it takes two days to charge it, is that really something you want. You need to seriously investigate the system you are planning to build/use.

      MT C

44. QUESTION:
    why don't you need to charge car batteries like you used to in the olden days?
    Every November my dad religiously brings the car battery in to charge it, he's done this since I can remember. He's got a newish car now and everyone tells him that it's not necessary these days, but to convince him I need to know actually why not. He's argument is how does he know it's not going to go flat, if anyone can give me a simple answer so I can pass onto him. battery

    • ANSWER:
      Batteries are more reliable nowadays, alternator regulators have improved, cars start much quicker with injection and put less load on the battery and overcharging and consequent water loss are things of the past, I started in the Motor trade in the early 70s and topping up batteries was a part of every service, but then there were tiny alternators and Dynamos and batteries were constantly charging and discharging.
      Your dad may well wreck the battery by overcharging it, by using an old charger with no regulator capble of delivering 15 plus volts, The battery may well gass, lose water, the acid gets too strong and attacks the plates, and the exposed area of the plates will sulphate. and become useless
      The ECU wont like being disconnected and the Radio will probably never work again. Connect a sealed 12 volt Motorbike or Burgler Alarm Battery to the F.A.G. lighter socket before disconnecting the main battery to avoid this, but insulate the dangling positive lead to avoid shorts, why a sealed battery, so you dont burn acid holes in the carpets.

45. QUESTION:
    Charging dead car battery through cigarette lighter.?
    I am planning to purchase a car battery charger that works by plugging it into the car's cigarette lighter. Does anyone have any experience with these? If so, how are they? Are they reliable? Have you had any problems with them? I have heard that charging a car through the cigarette lighter can damage the electrical components of the car. Is this true?

    • ANSWER:
      usually this is only useful as an emergency for

      someone not mechanically skilled enough to open the hood and attach cables to the battery +
      The battery is just barely failing and needs only a small amount of boost to be able to start the car

      Otherwise if you're intention is to charge at home from a wallsocket, just get a smart battery charger that you attach to the battery.
      2 recommended smart charger brands to take a look at are

46. QUESTION:
    How do i test if an alternator is charging my car battery with a multimeter?

    • ANSWER:
      While car is off the meter should read about 12.5v at the battery, with engine running it should read 13.5v to 14.5v.

47. QUESTION:
    How do I recondition car batteries to hold a charge?
    What can I do to make my car batteries hold a charge.

    • ANSWER:
      With your filter mask, gloves,face sheild, and apron on with no body parts exposed, remove the plates and clean them off, then refill it with fresh acid. The waste material is considered toxic waste so then you must find a battery shop to dispose of it.
      In other words, go get a new one.

48. QUESTION:
    charging mobility scooter from car battery?
    As i cant get my mobilty scooter indoors and cant have extension chord to car [dangerous to pedestrians] my scooter has 2 batteries and a charger box that connects to mains could i charge from car battery please?

    • ANSWER:
      There are products available online. Try this.

      http://www.google.com/products/catalog?q=Charging+mobility+scooter&oe=utf-8&client=firefox-a&rlz=1R1GGGL_en___US366&um=1&ie=UTF-8&tbm=shop&cid=16142243909635048380&sa=X&ei=zPbxTZymOqbL0QHD-rD_Cw&ved=0CGcQ8wIwBw

49. QUESTION:
    When charging a car battery, does it require the car to be driven? How about engine running but stationary?

    • ANSWER:
      The car can be stationary and it will charge. It will charge more quickly while the car is driven because the alternator is not running at full capacity when the car is at idle.

50. QUESTION:
    Can a wind turbine charge car batteries?

    • ANSWER:
      Yeah it can charge but only if it supplies the manufacturers specified input power rating for charging otherwise it may damage ur battery or it wan't charge at all.