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Old 01-24-2012, 08:35 PM   #25
herrhelmet
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Joined: Mar 2008
Location: USA West
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Quote:
Originally Posted by _cy_ View Post
that seems to be the basic problem ... aside from custom packs made from 4x A123 cells bundled together to make up 12v... there's very little information available.

what we need feedback on is the newer lithium iron phosphate batteries made from prismatic cells. which are just started to be marketed to motorcycles. for the electric scooter crowd lithium iron phosphate has a decent track record.

note... anyone that's used a new generation li-ion battery powered drill from Dewalt, Milwaukee, etc has used lithium iron phosphate batteries.

here's what's en route to me. a true 20AH lithium iron phosphate battery that happens to be the correct dimension for my R80G/S. note this 20ah battery weight 6lbs vs Shorai 18ah (claimed) weight 2lb .. conclusion so far ... not possible for a battery that weight 2lb to deliver a true 20ah capacity. note the balancer listed is for overcharge protection.

http://www.electricmotorsport.com/st...f_gbs_20ah.php



Shorai 18ah (claimed)
http://www.batterystuff.com/powerspo...18A1-BS12.html

I had the same notion about trying out these batteries about 2 1/2 years ago. I made my own A123 Cell pack soldered it together and said what the hell.... It was an 8 cell set up. 4 in series x 2 in parallel. A "4.6" Ah unit which seemed grossly underpowered for my BMW F650 GS.

So I could not believe it when it cranked the bike over. And over and over. At first I would just ride a few miles... but now I've had the same unit the entire 2 1/2 year period without a hitch. So, yes, I started selling a few to fellow ADV riders and searched for a better setup. That's why I went with the Ballistic over the Shorai.

First off, it is really confusing to lump LiFEPO4 (Lithium Iron Phosphate) batteries into the whole Li-ion class. Totally different chemistry and they don't explode. They do get hot but don't blow up...

Vehicle batteries come in 2 basic types: Those for starting which CCA (Cold Cranking Amps) mean high discharge rates for cranking the starter... but are not necessarily able to discharge down to a low voltage and be recharged.... and "Deep Cycle" or "Marine" type batteries that can discharge to a much lower voltage and be fully recharged over and over, but may or may not have high CCAs. That's why your garden variety lead-acid battery rates both its CCAs for starting and its Ah or amp hour capacity. Big batteries. That's why they're so heavy. They do it all.

The battery that cy shows is likely a marine type of battery that may not even crank over the beemers starting motor. It's rated at 10C pulsed which is the same as 10 cranking amps compared to at least 120 that the bike will need. The 20Ah is designed for a constant 3 amp discharge which would be perfect for a solar house battery.

The batteries I use are A123 26650 cylindrical cells made in the USA... and the Shorais use a similar chemistry prismatic made in China. I honestly can't say at this point which one is better since there has not been enough time to judge.

If the Shorais turn out to be the winner I will convert. But at this point, the Ballistic Components seem to have a better build with brass battery terminals, so I will stand on that.

As far as temperature affecting these, it's absolutely true. Here's a temperature chart in Celsius:



I'm not going to argue the science, but in practical terms the A123s are capable of quick self-heating at low temperatures
by 5-8 second starting bursts repeated 3 - 4 times at temperatures around 0F (Testing these on a 1979 Yamaha 340e at 10,000 ft. 0F in Brian Head, UT) Again, I was skeptical until trying them.

I think the Shorai batteries sell well and I have sold a lot of my own Sycl batteries and the Ballistics. The only difference being the Ballistic come in sealed plastic cases and the Sycl are shrink wrapped.

Cy--- if you want to test one of mine PM me and I''ll send you one. If someone comes out with the perfect battery I'm all over it, but these are pretty awesome.
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