6 ms·

Cheaper yes, better not really. IIRC li ion is better in every way except low temperature performance.

by hwillis 7y ago

m463 7y ago
Lead acid batteries are able to survive a complete discharge, which would destroy a lithium ion battery.
- ek750 7y ago
  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-battery-faq.html/ 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.
  - xnyan 7y ago
    It's not. Even a single complete discharge event is often if not usually enough to kill the performance of a lead-acid battery not intended for deep cycle.
    - m463 7y ago
      I'd say dozens of times in my adult life I've dealt with and recovered lead acid batteries that were completely discharged due to the headlights left on or similar.
- xnyan 7y ago
  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.
- hwillis 7y ago
  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.
zamfi 7y ago
> low temperature performance Doesn't that make li-ion unsuitable for, e.g., ICE vehicles that need to start at low temperatures? The batteries in EVs are definitely not as "forget about it" as the lead acid's in gas cars!
- dzhiurgis 7y ago
  You still get about half range in -20C with cabin heating.
- cloudwalking 7y ago
  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.
- goosehonk 7y ago
  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.
- oceanplexian 7y ago
  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.
  - daveFNbuck 7y ago
    A 33% drop in efficiency sounds reasonable for climbing a mountain vs driving on flat land. Do you know how much your range drops when you're driving in the cold but not climbing a mountain?

Cheaper yes, better not really. IIRC li ion is better in every way except low temperature performance.

m463 7y ago

Lead acid batteries are able to survive a complete discharge, which would destroy a lithium ion battery.

ek750 7y ago
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-battery-faq.html/ 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.
- xnyan 7y ago
  It's not. Even a single complete discharge event is often if not usually enough to kill the performance of a lead-acid battery not intended for deep cycle.
  - m463 7y ago
    I'd say dozens of times in my adult life I've dealt with and recovered lead acid batteries that were completely discharged due to the headlights left on or similar.
xnyan 7y ago
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.
hwillis 7y ago
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.

zamfi 7y ago

> low temperature performance Doesn't that make li-ion unsuitable for, e.g., ICE vehicles that need to start at low temperatures? The batteries in EVs are definitely not as "forget about it" as the lead acid's in gas cars!

dzhiurgis 7y ago
You still get about half range in -20C with cabin heating.
cloudwalking 7y ago
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.
goosehonk 7y ago
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.
oceanplexian 7y ago
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.
- daveFNbuck 7y ago
  A 33% drop in efficiency sounds reasonable for climbing a mountain vs driving on flat land. Do you know how much your range drops when you're driving in the cold but not climbing a mountain?