Found another pack supplier that looks interesting...

BMSBattery out of Guangzhou, Guangdong, China aka EcityPower:
http://www.bmsbattery...


For example, they list a 48V 20Ah LiFePO4 pack:
http://www.bmsbattery...


Size 150x160x350mm
Weight: 11Kg
Lifecycle: 2000Cycles (!!!)

Watt they are listing for $539 right now... I just threw one of these packs in their virtual shopping cart and they tack on $134.69 for shipping via DSL, so total $673.69 and they take payment by Paypal or credit card.

Then throw a "monster" 6A charger into the cart:
http://www.bmsbattery...


...another $44.90.

No change to shipping charge so total order $718.59. Probably gonna get dinged for HST at the border and a $10 brokerage fee... lets say $823.30 all in.

But good for TWO THOUSAND cycles? If so, equivalent to watt... maybe five lead packs, and this LiFePO4 with much better performance eg almost no voltage sag, better cold weather performance, a pack that is about 14kg lighter...

...and a faster charge? Most SLA batts are spec'ed to charge at 20% of Ah rating max, so for 20Ah no more than 4A. So 4 hours at 4A to refill the SLA pack from 20% remaining, while 80% of the LiFePO4 pack at 6A would take about 2 2/3 hours...

PROBABLY this pack should be good for charging at C/2 or 10A... would have to confirm. But if ya wanted to go nuts w/the thing, for $72.90 they offer a 10A charger. Full charge from 20% in 100 minutes!

Sweet...

Lock

Don't the faster amp charges degrade the battery somewatt :) ?

Well, there are usually "maximum" rates and "recommended" rates... So yah, max is possible and yah, cycle life as spec'ed usually takes a hit, but I usually go with "recommended", watt for most cheaper LiFePO4 is C/2... I might babble on about tech here, but just for the record my own priorities (safety a given) are high cycle life then energy density and Wh/$! So much of watt I read online about batts is consumed with power density, but the truth is, for safe/long-life discharge rates we are already "there" for 500W ebike needs. If ya figure 800W peaks, at 48V that's 16.67A, so a 1C discharge-rated 20Ah pack isn't EVen breathing hard...

Charge rates OTOH, most folks will still want to be able to re-charge as fast as possible w/out damaging the chemistry (ie shortening life.) One thing I like about the smaller low-amp chargers is they are just that, smaller, so more portable, and the smallest Amp-rated may not EVen need a cooling fan, so silent as well.
Guess my perfect smart charger would have selectable charge rates, w/lower A's for overnight or all-day charging. NEVer heard of anybuddy doing any damage from charging too slow!

I bought Headway LiFePO4 10Ah cells a year ago for the price ya can buy their 16Ah cells for today:
http://stores.headway...

Maximum Charge Current 5C(80A)

...so if yer talking higher quality LiFePO4, a C/2 rate may sound fast but really it's still "slow".

Lock

Found another possible replacement for a 48V 20Ah SLA pack. Only 15Ah but should produce similar Ahs to a SLA pack stressed by "high" discharge rates...

A 12V 15Ah A123 pack from A123RC, here:
http://www.a123rc.com...

...listed at $359.99 (plus shipping and HST...)

...so you would need four of these ($1440+!) to make up a 48V pack.

As A123 nanophosphate chemistry, these are LiFePO4 battery royalty. The pack is made up from A123 ANR26650M1A 2.3 Ah, 3.3 V cells, spec sheet here:
http://www.master-ins...

Some highlights for this cell chemistry:
Cycle life at 10C discharge to 100% DOD, over 1,000 cycles.
Normal 500W ebike use would be a discharge rate more like less than 1C, and if ya don't discharge 100% usually, these cells could be good for 2000+ cycles... And when they say "1000 cycles", they mean that at 1000 cycles these cells should still have about 95% of their original capacity remaining.

Four of these packs would weigh only .98kg... just over 2lbs.
...versus a 48V 20Ah lead pack that'd weigh about 25kg/56lbs! Just shaving 50+lbs off the weight of the bike would reduce Wh/km with faster accelerations and hill climbs and better range... And no discernable voltage sag at high discharge rates. Plus if you don't need to disassemble the bike to get at the pack, it'd be portable enough to keep inside for warmth and charging and security...

Operating temperature range to low of -30°C
...maybe not 365 days of a Toronto year but pretty close. The spec sheet doesn't say, but usually LiFePO4 cells need to be +0°C to charge... At -20°C, the spec sheet shows they still have about 80% of full capacity when warm.

I know at this price this is still a "Cadillac" solution for most folks here, but it's interesting to see where state-of-the-art LiFePO4 sits these daze. $1,440+ would buy a lot of 48V 20Ah SLA packs, but these A123 packs have so many additional features that would contribute to a better quality of ebiking life...

L0cK

A123RC selling A123 20Ah cells now for promotion price $36.99 each
http://www.a123rc.com...

16s 20Ah pack 48V ( 16 x 3.3V = 52.8V nominal) would then be $591.84 plus BMS and charger etc

Pretty amazing

Lock

The Codd Power 48V 20AH pack is available from ebay for $515 shipped, $469 if shipped by sea.

I went the cheap route as I don't need the pack until April. I had to ask the seller for a special listing for the sea shipping option.

I learned about Codd Power here, and about the seller from a member here, thanks.

Excellent Jonathan, good luck with that!

Found another deal on the go for lithium packs... GM Parts Direct is having a fire sale for 16kWh Chevy Volt packs:
http://www.gmpartsdir...

(Hehe... "fire sale" on Volt batteries... get it?)

GM part #20979876 usually at $2,994.64 on sale now for only $2,159.14!

What you get is a 16kWh pack made up of 288 LiMnO4 cells from the new LG Chem plant in Holland Michigan...


Info from GM on these packs here:
http://media.gm.com/c...

Lessee... 288 cells at $2159.14 = $7.50 per cell. Being Lithium-Manganeze cell voltage should be about 3.7V... Groups of three cells are welded together in parallel called cell groups so say 15x3=45 to make up a "48V" pack (really 55.5V)... from 288 cells, 6x 55V packs at $360 per pack with a few spare cells included

Dividing a 16kWh pack in six, at 55V each pack would be about 48Ah.

Group buy anyone?

Oh yeah, from here:
http://world-nuclear....

...LG Chem claims 40 years life for lithium-manganese spinel batteries for the GM Volt.

And from here:
http://endless-sphere...

The GM Volt uses LG chem NMC LiPo cells. They are 5C constant, 8C burst. They have extremely good safety, 10,000's of thousands of cycles...

Lock

I received information from Linda Lin of Headway that the 40160S is no longer in production.

She offers 32pcs of 40152S (15AH) for $19 each with connectors and holders. Add BMS, charger, and shipping, that should build a nice 48V 30AH pack for a decent price.

Too bad I did not wait for her reply and order another pack instead (she was apparently in India for a battery conference.)