Hey - I'm thinking about getting a pallet or more of lithium ion (LiFePO4) batteries shipped to Raleigh from China. I'm not having much luck finding these batteries on the East Coast.
I'm trying to gauge the interest in splitting a shipment. I need 20 or so for my scooter. Depending on the price, I may get enough to replace the lead acid batteries in my second scooter. There's a significant discount at 100 or so cells (the exact number depends on the amp-hours of the cells). Anyone interested?

3/15/2012 10:26:56 AM

need more details.

20 or so batteries with what capacity at what voltage for what price...

Looking for Amp-hours or Watt-hours, voltage, and Dollars please.

3/15/2012 10:29:13 AM

I'm looking at purchasing medium capacity (40-50 amp-hour) cells. They come in 40 Ah, 50 Ah, 100 Ah configurations. These batteries are larger than RC size - they're better for large-scale UPS, EV (scooter, motorcycle, car), or forklifts.

The test results from Company 1 (CHL) show that there are some very low internal resistance numbers for these cells. The anecdotal evidence is that under load the voltage drops are very small, making the batteries perform so much better than Thundersky, CALB, or GBS. So I could, for example, get by with using 18 CHL batteries instead of 20 Thundersky (but I'll get 20 and just enjoy the extra speed/capacity).
The other option is that Company 2's batteries (GBS, which are pretty good batteries, so I've heard) are discounted heavily (80 cents per Ah) in bulk right now. We'd need to get 10,000 Ah of batteries (they come in 40, 60, 100, 200 Ah cells) of the GBS batteries to get that discount.

I need 800 Ah - 1600 Ah at the most. So obviously, I need more folks to fill this level of batteries.

For those not familiar with LiFePO4 (and it's close variants), these batteries are good for 2000+ charge cycles (when treated well), so they are very long life and cheaper over the long haul than pretty much any other battery chemistry.

(this was cross-posted in the Tech Talk forum, too)

3/15/2012 12:03:27 PM

voltage / price?

3/15/2012 12:35:18 PM

Yup, let's talk prices.

3/15/2012 12:56:49 PM

I just got a quote for the CHL batteries at $1.15/Ah, based on a shipment of 10,000 Ah. So these very good batteries would be, e.g., $46 per 40 Ah battery plus a small shipping charge.

These are lithium ion batteries, so the nominal voltage is 3.2 V per battery (depending on state-of-charge: 2.5V to 4.2 V).

So to summarize:
CHLs = $1.15 per amp-hour ($0.36/W-hr)
GBS = $0.80 per amp-hour ($0.25/W-hr)

3/15/2012 1:10:31 PM

you're spending $1000 to make your scooter into an electric?

3/15/2012 1:17:33 PM

The scooter's already electric, but I'm planning on new batteries this year. I commute 13 miles each way across town. In gas savings alone, the batteries pay for themselves in less than a year. On top of that, the batteries should last for 5 years or more with my BMS.
Big picture.

3/15/2012 1:31:56 PM

is this how to calculate the cost to charge the batteries?

(3.2V per battery) * (40Ah per battery) * (20 batteries) = 2560 watt-hours / 1000 = 2.56kWh * ($0.10 per kWh) = $0.26 to charge it from empty to full

i have no idea how frequently you'd have to charge it, but i'm going to assume at least every other day for a total cost of about $33 per year

3/15/2012 2:04:32 PM

That's about right, quagmire02. I alternate between charging it at home and the office almost every day. I use about $25-$30 per year of home power.

3/15/2012 2:11:06 PM

3/18/2012 11:40:24 PM

I'm guessing the lack of posting means there's limited interest? I'm glad I didn't go ahead and make arrangements to buy!

3/20/2012 12:24:48 PM

You need 9 other people to drop a grand each on batteries... have you tried some more specific forums? Try RCGgroups... A lot of people there would probably be interested, though I dunno about a grand worth.

3/21/2012 3:14:46 AM

sorry, rcgroups.com

added too many Gs

3/21/2012 4:18:41 AM