A relative is going to replace the battery pack in his Honda Civic hybrid and is asking me about re using the old battery pack as a house battery.
The battery is an NiMH consisting of "sticks" of 10 D-Size cells (1.2 volts each) for 12 volts. He wants to test and select the best remaining sticks and re-assemble them into a 12 volt pack. I think there are 120 sticks.
What I can't seem to find is good info on the correct charging methods for a large array of NiMH batteries, how to determine the proper charging voltage and state of charge.
Any comments here?
NiMH batteries were used in small jet aircraft for years, don't know if they still are. They were used because of the large amount of power needed to start a jet engine.
Problem was they could run away when being charged and would explode and burn.
Further research is surely needed before you commit to using them.
I don't claim to be an expert but would strongly recommend you closely study the charging system Honda uses.
You could certainly charge individual 10-cell packs using chargers designed for modellers; Ni-MH D-cell battery packs with various number of cells are widely used in radio-control model aircraft, boats & cars, and there are very sophisticated chargers available designed to squeeze the maximum performance out of them.
But quite how you scale that up to charging 120 packs simultaneously I'm not sure.
Jeremy
In the large systems, each sub-unit of x cells is fitted with its own battery management system that controls charging and discharge to keep the individiual cells operating within strict limits.
With the charging and discharging management system the should be used to prevent fires, these batteries are just not cost effective for use on an RV. Good Luck, TomC
Do Nickel-Metal Hydride batteries have the same fire potential as Lithium Ion batteries? I wasn't aware that NiMH batteries were a fire hazard.
I agree with Tom that trying to use these in a bus would be problematic unless you just want a challenge. Doesn't the old Honda hybrid battery get recycled when it is replaced? My co-worker had the battery replaced in his 2001 Prius recently at 150,000 miles and the dealer kept the old battery. Maybe he could have kept the old battery, but I have no idea how he would have gotten it home.
I take back all I posted!!
I was thinking of Lithium batteries all the time!! Sorry about that!
I don't think Nickel-Metal Hydride batteries even existed in those days, probably 20 years ago - or more.
Maybe find a wrecked Civic Hybrid and buy the charging system from it? Just thinking aloud :-)
I am still trying to find out how i can hook up to the free charging stations at wally world cause no one uses them...
Then I can just park sideways in about 4 of them..... ;D