Electric vehicle batteries and chargers

Well,, I just replaced half of my silicone battery string with the BB batteries - the No. 2 and No. 3 "buddy" pairs being the BB's. I am having some problems.

Charging the half-new pack resulted in the powercheqs working awful hard. So, checking the charging with the powercheq's disconected yielded 16.2 volts for each of the BB's and about 13.9 volts for the silicones during equalization charging, and about 14.4 volts for the BB's and 13.6 for the silicones during float.

16 volts is well into the gassing range - not good for the new batteries at all.

In the comment posted by 'bluebushido' he quoted Steve M with this:

I recently got a new Evader scooter and it works great, but I noticed that the charger is a 24V charger even though it's a 48V system. Does anyone know how that might work? Could the charger be charging two sets of two batteries in parallel?

I was surprised to see white powder build up on my bike frame behind and below the battery pack. There was this powdery stuff at the lowest edge of the bottom bracket and also above the bracket. It seem to come from *under* the paint. I have 4 12Ah SLA's in a single pack slung in my frame and wrapped loosely with a piece of old naugahyde material. I pulled off the cover to inspect the battery pack and it all looks intact but there was more powder on the inside of the cover in spots and on some bare metal parts of the mount. Yikes!

Feature articles 2006
Hybrid electric vehicle made possible
http://www.electroline.com.au/elc/feature_article/item_122006b.asp
Elizabeth Latham, Electroline journalist

The electric car has been a dream in the pipelines since the early 19th century but has always seemed out of reach because of battery life, cost and weight. Now a hybrid electric vehicle has been made possible with the development of a long-life battery by Technology Research Laboratories (TRL) in the US.

Using the charging ports, I'd like to use a resistor to simulate a ~35 amp load on each of the 16, ~4 volt li-ion parallel subpacks separately, measuring the voltage drop in order to help isolate any bad cells.
I only know one of the three variables in ohm's law -- the battery voltage. So how do I calculate the resistance needed?

Just a li-ion performance consideration I've run into using cheap 18650 lithiums that other folks have noted with Thundersky cells too. My batteries are spec'd for 1.5C, but only provide 1C at less than 50F.

All:

This is a repost from

http://autos.groups.yahoo.com/group/EVespaCloneClub/message/1186

I've been charging the batteries in Buttercup (4 @ 12V x 17AH) in two strings of two. (in the background at http://www.austinev.org/evalbum/822)

Four months ago, I started with a set of four new PowerSonic 12018 batteries.

Here's the deal: due to cold weather, plus maybe aging, my 16s15p 2.2ah 1.5C lithiums are only putting out 30amps total after 25% of pack capacity is drained. Extra voltage droop under 30 amp load is also preventing my formerly 35mph bike from going more than 30mph -- unacceptable!

Here's my radical hybrid idea: Add in parallel one 3ah emoli lithium mangenese cell to each of the 16 parallel subpacks of lithium cobalt cells. So the total pack would be 16s16p (15p li-co + 1p emoli)

Projected benefit: With it's much lower impedance, the single extra emoli per subpack (impedance of these cells supposedly does not increase over the life of the cell as it does for lithium cobalt) I'll be sure to get my full 35 amps back, plus less voltage droop, plus a bit longer run time, plus less wear on the lithium cobalts which apparently are not really 1.5C cells after all.

Got one of these: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91129

Works great, but want to modify it to work continuously, or atleast for a few minutes at very high current. Has anyone here done something similar? Any ideas?

Simplest way I guss is to drill a hole and use a spray bottle to cool the element. Air cooling probably won't cut it.