3 ms·

Have given this a fair amount of thought and it comes down to a few things: Cycle lifetime of lead is good as long as you don't deep-discharge it, but then if

Have given this a fair amount of thought and it comes down to a few things: Cycle lifetime of lead is good as long as you don't deep-discharge it, but then if you don't deep-discharge it you need a lot more material. Eventually the lead is going to degrade and then you need a battery changeout, or you need the wherewithal to refurbish the plates and the paste. No one goes to the trouble. Lead-acid doesn't tolerate the cold as much as lithium does. But the big enchirito is the fact that lithium batteries at 100% max capacity are great for cars. After they wear down to 75% max capacity they're no longer suitable (you want a pack with 20 miles' range?) and junk. At that point they're ideal for grid-tie because there's literally not much other use for them. Lead acid requires purpose-building, which I believe would be cost-competitive, but also require a substantial raise for what many consider to be a has-been technology.

ericd 8y ago
This is a great point - there's going to be a lot of used lithium car batteries available x years after electric cars go big, and I don't know of any better use for them than grid storage. So it seems like those will be priced at their value for grid storage. Which means that once there's a sufficient supply, they will almost inevitably become a major force in grid storage.
Gibbon1 8y ago
My company was designing a product that was solar powered with a battery to keep it running at night. We originally were designing in lead acid batteries and the size of the battery needed for that kind of service was too large. De-rate because you're cycling daily and suddenly you need 3X the battery. De-rate again for environmental conditions and add another 2X. We punted and switched to a lithium iron phosphate battery. Because we could get away with a 2.5 amp-hr lion battery vs a 12 amp-hr lead acid. It's cheaper and we don't have to worry about a workman trying to lug 15-20lbs up a ladder.

ericd 8y ago

This is a great point - there's going to be a lot of used lithium car batteries available x years after electric cars go big, and I don't know of any better use for them than grid storage. So it seems like those will be priced at their value for grid storage. Which means that once there's a sufficient supply, they will almost inevitably become a major force in grid storage.

Gibbon1 8y ago

My company was designing a product that was solar powered with a battery to keep it running at night. We originally were designing in lead acid batteries and the size of the battery needed for that kind of service was too large. De-rate because you're cycling daily and suddenly you need 3X the battery. De-rate again for environmental conditions and add another 2X. We punted and switched to a lithium iron phosphate battery. Because we could get away with a 2.5 amp-hr lion battery vs a 12 amp-hr lead acid. It's cheaper and we don't have to worry about a workman trying to lug 15-20lbs up a ladder.