Honestly it’s just market inefficiencies at this point. I build battery packs for drones and RC planes and the lead acid stuff is just garbage. They can’t perform to more than 60% of their rated capacity and then start voltage sagging. The energy density is pitiful. A small UPS under your desk with LiFePo4 cells would outperform the lead acid 3-4x for the same space and last longer for the same or less money.

You still get about half range in -20C with cabin heating.

In some ways they are more "forget about it" than lead acid -- lithium battery life is measured in cycles, rather than time. Your lead acid battery will be dead in 5 years, but your lithium batteries can last for 5,000+ cycles, even more if the cells are intelligently discharged.

As for cold temperatures -- less current can be drawn from each cell. In those cases, you can add more cells to still perform adequately in the cold. And this may even fit in the same form factor as the existing lead acid battery, because lithium batteries are physically smaller.

Lots of motorcyclists replace their lead-acid batteries with lithium-ion batteries that are much lighter. They’re very unreliable but some people will deal with that to save a few pounds.

I imagine you mean ice cars with much more demanding starters, but worldwide motorcycle market is pretty big.

Yeah I have an EV that gets 240 miles on a warm summers day but it drops down to like 160 on a day where it’s below freezing climbing a mountain. I’m OK with that. It’s still an absurd amount of range for a technology that would have been unthinkable a decade or two ago. I think once EVs start surpassing ICE cars in range it will be a non issue for most people.

An li ion battery of the same capacity will supply less cranking current, but you can make it slightly larger (still much lighter and smaller than SLA) and make up for that difference. It's only below -30 Celsius (-20 to -40 depending on the chemistry) that lead acid retains better capacity, and they freeze completely at -80.

Li-ion will last far, far longer than any lead acid under any conditions.

This doesn’t sound entirely right to me. lead acid batteries do get damaged by deep discharges

even “deep cycle” lead acid batteries aren’t supposed to go to full discharge. from https://www.solar-electric.com/learning-center/deep-cycle-ba...

> Deep cycle batteries are designed to be discharged down as much as 80% time after time and have much thicker plates. The major difference between a true deep cycle battery and others is that the plates are SOLID Lead plates - not sponge. This gives less surface area, thus less "instant" power like starting batteries need. Although these can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 50% discharge.

Deep cycling performance depends on the battery chemistry. Most cars in the US use a type of lead-acid battery that can't be deep cycled even a single time without serious risk of damage to the cell. I would assume this is true of any lead-acid battery not intended for deep cycling everywhere else in the world too as it adds significant cost to battery.

Lol you are absolutely wrong. Li-ion cycle life is typically rated at 99% depth of discharge, rarely at 98%. That means .5 to 1% of maximum capacity without damage.

Deep cycle lead acid is damaged permanently at less than 20% capacity. Manufacturer recommendation is to avoid going below 50%. "Deep cycle" means going below 50% won't immediately destroy your battery... Like most car batteries.

Desulfation can help but will never fully recover a lead acid battery. If you discharge a lead acid battery -any kind- to 1%, it is fucked.