Eric Hanson wrote:I agree with your wife that Lithium-Ion batteries are not practical, pragmatic or cost-effective for an off-grid home. Lithium-ion batteries, despite all the hype, are really niche performers, excelling in applications that require high power and energy densities in a small, light package. These are just about perfect for laptop computers and power tools. They would be great for Electric Vehicles if it were not for their high cost and limited charge-discharge cycles. But a fixed application like a home requires neither a particularly high power or energy density. Old, heavy, reliable batteries will do just fine.
Perhaps the best type of battery for your particular application is the Lithium Iron Phosphate (LIPO) battery. These are a far cry from the better known Lithium Ion battery. LIPO batteries are pretty light, have medium power and energy density, can be fully discharged and have something like 10,000 charge-discharge cycles, making them a long-term battery. They are not cheap, but they are very reliable and don't have any of the stability (read as flammable and explosive) issues that Lithium-ion batteries do. Also, standard battery charging electronics generally work just fine with them.
James Freyr wrote:Yes you can. A 12v charger can charge any 12v battery. The difference is your scooter battery is 7ah (amp hours, for those reading who may not know) and a car battery is hundreds of amp hours, so it isn't going to take very long to charge the scooter battery compared to a automobile battery. If the charger is an old analog style where you turn a knob to set the number of hours to charge, put it at the lowest setting. If it's a new digital charger, it should know when the battery is charged and will stop charging. Over charging makes the electrolyte liquid in the batteries boil and it just kills the life of them, then they lose their ability to hold a charge. If it's charging and you hear fizzing like soda pop, the electrolyte is boiling, so stop charging.
One more note, is the age of the battery in question. If this scooter battery is 5 or more years old, and it's a lead acid battery, it may just be time for a new one. There are interesting techniques I've seen on youtube of revitalizing old lead acid batteries by dumping the electrolyte, then filling with a epsom salt solution, and getting many more years of life out of them. I have yet to try this myself, but the information is out there.