Replace Motorcycle Battery with LiFePO4
 

Knowing I had a 1pm appointment with the DMV, which had to be scheduled 2 months prior, I fumbled around in the garage last night until I finally managed to solder 10 gauge wire onto nickel strips. Then I spot welded those strips to the LiFePO4 battery + and -

Well, I've found 1 unsuccessful way to make the main battery leads, and here I am on the forum instead of the DMV. The appointment is rescheduled... 2 months out. I might as well not bother with registering vehicles as long as Oregon isn't serious about it.

The bike almost started a couple of times, but then lost power entirely once the positive lead burned off. I popped the seat off and found a tiny bit of smoke rising from where the positive lead used to be.

Strange that it failed considering I had tested several times with the original nickel leads. Perhaps the strips I used were slightly thinner gauge?

What's the best way for me to get leads with ring terminals on this battery? Ideally I'd just solder the 10 gauge wire directly to the cells, but I'm afraid that would be too much heat for the cell, and I'm not even sure my iron could get hot enough.

Anyhow, this thread is split from this one so that I can focus on the topic of replacing motorcycle batteries with lithium iron phosphate (LFP);
https://ecomodder.com/forum/showthre...po4-36693.html

https://ecomodder.com/forum/attachme...1&d=1630441989

https://ecomodder.com/forum/attachme...1&d=1630441989

Nice!

I've thought about LiFePO4, not only for the 12V, but also for the hybrid batteries in my Toyotas since there seems to be a growing group that's having success replacing every block of NiMH cells (12 cells) with 5 LiFePO4 cells.

But I think it's too cold where I live for LiFePO4 to work properly without damaging them.

Interesting thought to replace the traction batteries with LFP. It can be done without modifying the BMS? I've had a LFP for the 12v battery in the Prius for the past 6 years so far. Haven't done any balancing either. It lives inside the cabin so it should be reasonably protected from freezing.

No mod needed for the BMS since apparently 5 LFP cells work with the max/min voltages the Prius' BMS will deliver. So as long as your LFP cells can handle the current you should be good.

There's a guy over on the Prius Chat forum that has developed a LiFePO4 replacement kit for Toyota hybrids using the 6 cell "blade" or "sandwich" NiMH modules. I guess he's the guy that developed the Dr. Prius app. He's got a lot of seemingly well known Prius enthusiasts that have been testing his kits over the past few years that are all que happy with the result. The guy's sales pitch seems a bit flakey though and seems a bit apprehensive to give solid numbers.

For me temperatures as low as -30⁰F every year are common. Here close by we had a record of -60⁰F and I've personally been in -52⁰F weather here. It seemed like for many years we'd see -40⁰F for at least a week every winter. And well, I don't have a garage so if it's in the car it will freeze. When we had the Leaf we sure found out that if cold enough the car would go only 30 miles on a charge even with the heater off and trying to hypermile.

My current hypothesis is the nickel strip material that came with my spot welder is actually nickel plated steel, so it may have more resistance and therefore burn off. I put a test piece in salty water and it showed a few streaks of rust forming.

I could buy pure nickel strips and see if that fixes the issue. I could also try doubling the strips up... or I could just solder thinner gauge copper wire directly to the battery.