Experiments with $40 'starter' lifepo4 for engine cranking

[Vigo]

Have you had any issues with the charge coil on lawn tractors messing with the BMS?

So it's not on a lawn tractor per se (my little tractor picks up ~1000lb on the front, ~500lb on the back, 4wd, diff lock, has a PTO etc etc) but the charging system is basically identical anyway.

Since im using a PWM charge controller i think even a 'pure' DC source would still appear 'choppy' after it gets PWM'd to the battery, so conceptually i dont think the rectified-but-unfiltered dynamo output would be any worse or different from just using a PWM scc in general.. This is just my assumption based on my understanding, but i have NOT checked AC ripple on my charging circuit to verify what it actually is!

I don't believe i've had any issues relating to the charging system BUT i do have a mystery drain or parasitic draw somewhere which i haven't spent the time to diag yet. The batteries have no issue cranking the tractor when they are charged, but the last two times I used the tractor i had to jump start it because the batteries were dead. It's probably something simple but i haven't investigated it yet.

 

[Vigo]

Ok, so a cracked wire had the 5w solar panel inoperative, and i believe the drain was simply the SCC. If this was a car with 60-100ah of battery being driven every day it would be a non issue, but since i have ~22ah and only start the tractor periodically, i believe the SCC consumption in the lack of any solar input was enough to eventually drain the batteries.