c4Lvin said:
jkline said:
When I replaced mine, I hooked a battery charger up to the battery connections, loosened them, removed old battery, connected new one, removed charger cables and done.
Would it not be dangerous for the Leaf's electronics to go faulty with a high voltage 14.5 upwards charger going into the terminals?
I've seen my Leaf battery go above 14v with Leafspy. I have thought about replacing the stock battery with a li-ion or a lifepo battery, I would build a DIY battery to maximize energy storage. I wouldn't do it for costs, but to improve the quality of the vehicle.
Using a BMS like
this, you could create a battery that could be over 2x the capacity of the lead acid battery, with less weight. My Leaf has a solar panel, and I've seen it produce several amps to the battery on a bright day. Realistically the safest would be to go with LifePo cells, 3.2 nominal and 12.8v 4s nominal voltage.
This BMS would be ideal. A 3s li-ion bms may work, but that is lower voltages, 12v being max and 11v nominal.
There are also 45-60Ah BMS available but that might be overkill and will cost extra. I've read that you supply current to the BMS, and it will regulate cell charging, including Constant Current charging from lead acid charging methods. This should be safe up to 6 cells in parallel (All in parallel same charge/manufacturer lot). I would look into
15Ah Lifepo Cells, they are 165mm tall, so should fit in an enclosure. But probably not any/many in parallel, there are also 20Ah/30Ah cells available that will fit in the enclosure. I really like what DjDemonD did
here.
Quick calculations: you could store 4 in a row (parallel), and 4 in a line (series) in that enclosure, with room for the BMS. Using 16 20Ah cells you could store about 1kwh (16 cells * 20Ah * 3.2v = 1024kwh), or 320Ah. That is almost a 10x increase over the Lead Acid hazard. I run many accessories off of my 12v system so I see many benefits. Though the cost would be almost $500 for all needed parts and cells.