Sunday, November 23, 2008

Batteries ordered

After months of debating which batteries to buy the deed is done and there is no going back. I originally started this build with the idea of using the typical LA(Lead Acid) battery as the power source. After doing the math and seeing what other EVs range seemed to be it didn't seem LA could really get the range I was looking for, at least not without making my car weigh in a 4,000 lbs. I ordered 45 of the ThunderSky LFP-160Ah modules at $264 a pop, not cheap. On top of that the charger and BMS system added another $3,000. The full setup was ordered from Elite Power Solutions.

The amount of money up front for this setup is scary but after doing the math the investment should be well worth it in the long run. First off I can get about four times the capacity out of them as LA pound for pound. The setup I ordered will add 550 lbs. of lithium to the car which should keep the overall weight of the build at or maybe slightly below the original weight. This compared to most EV conversions needing the suspension beefed up to support the extra weight. Lighter will also mean faster acceleration than with the LA and also less power required to accelerate.

A standard LA battery last around 200 charges. Some of the higher end cells can go as much as 400 cycles. Cycle life of the lithium cells start at 1000 and go as high as 3000 cycles for 70% DOD. If I used flooded LA and got 200 cycles out of them I would still break even if I only got 800 cycles out of the lithium cells so I shouldn't have any trouble getting my moneys worth if the cells hold up....we'll see.

Hurry up and wait. So now that I finally committed to this purchase I get to wait for 5 to 9 weeks for them to arrive. UGH. I'll take this time to work on the electric systems of the car and hopefully have things ready to go when the cells arrive.


Anonymous said...

what is your anticipated range and top speed with the battery / motor setup you have selected? I am very closely watching your conversion as a model for mine!


Brian said...

I'll definately post the real results as soon as I know, but I'm guessing a range of 100 miles give or take and a top speed of around 90 mph.

LeftLibertarian said...

Holy crap. That is $12,000.00 for batteries and then another $3K for the charger. Ouch!

So much for your original $6K conversion estimate.

LeftLibertarian said...

Can you verify my math here . . .

3.2V*45*160Ah = 23.04 Kilowatt-hours

($264 * 45)/23.04KwH = $515.62/Kwh

Is that correct? Seems like a pretty good price.

Brian said...

Yeah the original estimate was hoping I could get by on some cheap lead acid batteries. Not even close.

Looks correct on the pricing you did. You'll usually see it calculated per Ah. Like I think these were $1.60 or maybe $1.65/Ah.