Lithium, Lead, Amp-Hours, and EVs

by Kurt
(Wyoming)

Lithium electric car battery

I was wondering what the differences would be between doing a conversion using Lithium Iron Phosphate batteries that have 100 A/h and one that uses golf cart batteries like the Trojan T-105 that have 225 A/h.
I know the LiFePO4 batteries are the favored batteries if your budget can handle them. but it seems to me that the higher the A/h rating the better for an EV. Is this correct or would the lithium batteries still be the better choice.

Hi, Kurt -
It's a matter of weight and distance you can travel.
The LiFePO4 batteries at 100 AH will not take you as far as lead batteries at 225 AH, but they'll be a lot lighter.

Amp-hours are a measure of how many amps your batteries can deliver times the number of hours they can deliver the amps. (The way you wrote it up there, it looks like amps-per-hour, but that's not correct. It's actually a multiplication, amps times hours.) An amp is an amp, no matter what battery chemistry. An hour is an hour, no matter which clock; )

Now, amp-hours are notoriously heavy; comparing the same battery chemistry, more amp-hours means more weight.

But you're not comparing the same chemistry, or the same AH rating. Lithium has more bang-per-pound than lead, so if you had two batteries sitting side by side of the SAME AH rating, but one was lithium and one was lead...the lithium battery would weigh a lot less.

That means with lithium, you can load up your electric car with more amp-hours, and go more miles between charges - or you could just keep your car light and nimble on its feet with less weight and the same number of amp-hours.

Regards,
Lynne