Prius 12v battery replaced with LiFePO4

[ME_Andy]

I had no idea it could be this cheap. Might have to do this soon

[jamesqf]

Originally Posted by vskid3

Because (at least on my Gen2 Prius) the cabin lights don't turn off automatically if a door is left open...

OK, from the context I thought you meant leaving the garage doors open.

Still, one of the first things I do when I get a car is to disable that switch that turns interior lights on when the door opens - thus ruining your night vision, and letting anyone outside see you. Not to mention allowing your battery to run down if you're careless :-)

[hayden55]

Off topic what's the charging efficiency on the prius plug in HV battery? I heard it was around 80% of the energy used for charging the car is actually put into the battery?

[Daschicken]

I assume that LiFEPO4 battery had the motorcycle style battery attachment with the small box posts and a screw. What kind of cable ends did you use? I am thinking about a LiFEPO4 conversion for my car when the battery dies, and that would be very helpful information.

[ME_Andy]

Two years later, my lead-acid battery is about to be 5 years old. I'm pulling the trigger on a Christmas present for myself. Bioenno Power 12V, 500 CCA, 20-30 Ah "lead acid equivalent." 4.4 pound weight. The website says it can handle a brief spike to 625 CCA. I'll put a supercapacitor in parallel, if I have to...

https://www.bioennopower.com/collections/480-to-500-cca

With the BLACKFRIDAY promo code, it's 15% off, so my total cost will be $216. That's about the same as a high-end lead-acid battery, anyway. I'm very excited.

I'm currently googling whether I can charge this battery up with a power supply or if I should spend the extra $15 for a charger. I guess I can charge it with a power supply.

[oil pan 4]

You can charge a LiFePO4 with an automatic digital charger on the "gel battery" settting.

[Ecky]

I've ordered a LiFePO4 battery for my Insight to put in parallel with supercaps and want to get some thoughts on protecting the battery from cold damage.

My initial idea was a large resistor to the battery so most of the starting current and subsequent charging would be to/from the caps, but the battery could still keep the caps charged and allow me to have lights or radio on for more than a minute before losing the ability to start the car. However, I had the idea of a large resistor just to dramatically slow charging in subzero weather, and maybe use a pair of diodes so it can discharge at full speed. Or, maybe a resistor in both directions but a higher impedance one in the charging direction.

Does charging at all at low temperature damage the battery, or is it rate dependent?

[redpoint5]

From what I've read, it is rate dependent, with the battery being much less tolerant of accepting a charge when below freezing. That said, I don't really have much experience with that, and I don't know to what degree it damages the battery.

I've thought of using high power diodes and allowing full current discharge, with a resistor in series for the charge side. There would be a voltage drop though. For that reason I'm inclined to use a single resistor to limit charge/discharge.