Battery Replacement

Near zombie thread. This was on a motorcycle, not a car, so keep this in mind. Had an AGM for years. Heavy, but reliable. Put in a quality lithium, LiFePo4. Light as paper. Nothing but problems. If you accidentally drain the battery, it's fried. Some brands offer a shutoff for this to stop from happening, but this one did not. Company warrantied the battery, sent me new. In the cold, it's a nightmare. Had to let to "warm it up" by running the heated grips for 30 seconds before cranking (this is per the manufacturer), and even then it was always a crapshoot if the bike would start. I wasn't doing winter riding, but I was in some alpine conditions where the low was down in the high 20s. Barely got the bike started. Never felt comfortable with the battery and worried all the time if it would start. Replaced it with an AGM which was 1/2 the cost, 2x the life, and 5x the cold performance. For mission critical, I will always pick AGM over lithium.

 

Interesting take, thanks for sharing.

Yeah, cold performance, particularly at/below freezing, is the Achilles heel for lithium chemistry. But I still plan to go with lithium for a seconday / house battery on the vehicle, due to all the extreme advantages in power density, charge cycle life, depth of discharge, and even shelf life when not in active use. Probably keeping a quality AGM as the primary vehicle/starter battery.

I'll shop around and see if there are any lithiums that are specifically engineered for cold use, maybe with extra insulation and/or automatic internal heating.

BMS boards (battery mgmt system) in quality units should be good enough to prevent the battery getting damaged by over-discharge in any conceivable operating condition, including dead shorts & super cold conditions.

 

For example, Dakota Lithium specs their 12V starter/automotive batteries to being usable down to -20ºF, by means of an internal heating element.

https://dakotalithium.com/product/d...r-starter-deep-cycle-lifepo4-battery-1000cca/

DL has gotten very good reviews consistently for years. $600 seems pretty fair for a lithium starter battery w/ 11-year warranty compared to a $300 Optima yellow-top AGM that can only reasonably be expected to last 5-7 years max.

I wonder what the exact details of their internal-heater technology is. If lithium itself is really no good much below freezing, maybe they have a separate small high-quality lead AGM battery inside the unit to provide backup heating capability to get the main lithium up to minimum operating temperature? I'll certainly research more before making a purchase decision.