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?
Yes, this will work with the jump cables. How long it takes depends on the size of the batteries and the current that your alternator can deliver.
It will work, after a fashion, but: You won't get much charging out of that alternator at idle. (You'll want that engine at about 1200 RPM minimum.) You will be draining the car battery initially. (This might be a serious drain if the battery bank is large in comparison to the car battery.) If the battery bank is much larger than the car battery, you might be overloading the alternator when you first start recharging. Don't let it heat up too much.
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
