Lithium batteries

[lowell]

I gutted an old dead PC680 and refitted it with 24 A123 cells in a 4s6p configuration. 5lbs 2.3oz and starts a Supra with AEM EMS/CDI, through jumper cables and rear mount battery wiring no problem.

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2335g. 5lbs 2.30oz.

Lithiumpros C680 is a 4s5p pack. Funny thing is there's actually space for 28 cells inside a 680 case.
Lithium Pros

 

[97gst_spyder]

CCA's? Have you measured them? A stereo shop should be able to test it.

 

[lowell]

I'm not concerned about CCA because it doesn't usually get down to -18C here, I don't crank the car for 30 seconds, and 7.2v may not start the car anyways. While I agree it's a useful number to compare amongst batteries, I doubt most racers care.

The cells are rated 30c continuous and 60c burst, so 414A cont. and 828A burst. I recently tested an EVO @ 280A cranking a cold motor.

Just tested my car: sitting all day, 12c ambient, KOEO 13.1v, cranking RPM 218-250 up and down, cranking voltage @ ECU 11.3-11.5v fluctuating with compression. 6s steady cranking with the CDI unplugged. Peak inrush current 202A and then 140-145A to maintain.

 

[turbotalon1g]

Nice i'd like to rock one, but in the fall it gets pretty cold.

 

[lowell]

University of Vermont SEED Project Ezekiel - Standards friendly design by wehnerj

I thought about freezing the battery pack but that doesn't account for thicker oil etc. at low temps. Need to find a freezer I can drive my car into!

 

[greengoblin]

We need a how to thread.

 

[TSiAWD666]

Yeah, I have a spare pc680 sitting here dying for a diet plan...

 

[snowborder714]

We need a how to thread.

I agree. Anyway you'd be able to post up info on how to do this Lowell?

How would you think your battery would stand up against this one?
https://www.pegasusautoracing.com/productdetails.asp?RecID=9405

 

[lowell]

I agree. Anyway you'd be able to post up info on how to do this Lowell?

How would you think your battery would stand up against this one?
https://www.pegasusautoracing.com/productdetails.asp?RecID=9405

All the cells are the same A123 cylindricals, so my 24 cell will have 50% more capacity and cranking amps than that EVO2 16 cell. There's not really much to say about the assembly, I just soldered the cells together and attached leads to them.

How To Build a Battery Pack from A123 Cells - RC Groups

The terminals on the PC680 are held in by 12 point 13/16" nuts. You'll need to machine the OD of a socket down to fit in.

 

[snowborder714]

Thanks for that link. I've never seen how battery packs are wired together, so that really helps!

I'm guessing (since my searching didn't lead me to any info) that 4s6p means 4 bundles with 6 cells in each?

Where did you source your cells from? Brand new or recycled them from another battery pack?

 

[kbiker76]

You can all way's buy a lithium car battery now. They just started producing them not too terribly long ago I believe. I work in a battery warehouse and we just started carrying the motorcycle lithium batteries and they are so amazingly light its crazy!

 

[ed1380]

Thanks for that link. I've never seen how battery packs are wired together, so that really helps!

I'm guessing (since my searching didn't lead me to any info) that 4s6p means 4 bundles with 6 cells in each?

Where did you source your cells from? Brand new or recycled them from another battery pack?

It's the opposite 6 packs of 4

I read it as 4cells 6parallel

I know you can salvage them from some power tool packs

 

[lowell]

Thanks for that link. I've never seen how battery packs are wired together, so that really helps!

I'm guessing (since my searching didn't lead me to any info) that 4s6p means 4 bundles with 6 cells in each?

Where did you source your cells from? Brand new or recycled them from another battery pack?

4s6p means 4 series, 6 parallel. I had to interconnect the cells to make them fit inside the case, but the next pack I do will be in a more ideal configuration with a case to match the cells, not the other way around!

The pack was new from www.ebikes.ca Homepage of the revolution, but next time I'll just buy new R/C cells.

 

[gprix1]

Definately interested in doing this. I have a dead PC680 that is just taking space right now.
Found a bulk pack of 25 genuine A123 cells for $219 shipped. Has anyone found them cheaper?
25 PCS NEW A123 BATTERY LITHIUM-ION LITHIUM ANR26650M1A 26650 3.3v 2.3ah Lifepo4 | eBay

 

[lowell]

Cell Man has the best prices on A123 anywhere.

Shop Online

 

[snowborder714]

Thanks guys for the corrections on my lack of understanding 4s6p!

Do you know if there are any rules/regulations/guidelines around basically making your own battery, case and all? This could be interesting as you could build it to fit in a specific spot to keep weight in right places (what little there is) and tuck it out of the way.

 

[lowell]

I don't know of any rules or regulations, other than it must be securely mounted. If I can push the car by the battery, it's secure enough IMO.
Rear mount alternator, shorten all wiring, ditch the heavy stock terminals, battery low down and against the firewall =

 

[snowborder714]

Cell Man has the best prices on A123 anywhere.

Shop Online

It looks like they either don't exist any more or do not stock them.

Actually, it looks like it's pretty darn hard to find these cells period at the moment.


Edit: I guess it doesn't help that A123 Systems went bankrupt back in October.

 

[lowell]

It looks like they either don't exist any more or do not stock them.

Actually, it looks like it's pretty darn hard to find these cells period at the moment.


Edit: I guess it doesn't help that A123 Systems went bankrupt back in October.

A few people on another forum reported good results with
Nano-Phosphate LiFePO4 Original A123RC ANR26650M1A Cell_A123RC Element/Cell_A123 RC Battery|High Quality Battery|Wholesale Ebike Battery

 

[turboglenn]

these lithium ion or lithium polymer>? I ask because there's the "smart chip" used for balancing and regulating charg on packs that contain both parallel and series connections being the most vital as far as the need for this "chip". As i've udnerstood and been unfruitful in my searching, it's one of the closest gaurded secrets in the industry on how the firmware or software (unknown which) is written or how to decode and or reset it (that's why laptoip batteries will stop cahrging because this chip tells it after a certain number of charges it's "dead") because the li-po especially can and do catch fire oand explode
i'm not knockig the idea but looking for knowedge on these cells and packs based on projects of my own that never came to fruition because of issues with making packs that i feel safe charging without the smart chip

 

[lowell]

these lithium ion or lithium polymer>? I ask because there's the "smart chip" used for balancing and regulating charg on packs that contain both parallel and series connections being the most vital as far as the need for this "chip". As i've udnerstood and been unfruitful in my searching, it's one of the closest gaurded secrets in the industry on how the firmware or software (unknown which) is written or how to decode and or reset it (that's why laptoip batteries will stop cahrging because this chip tells it after a certain number of charges it's "dead") because the li-po especially can and do catch fire oand explode
i'm not knockig the idea but looking for knowedge on these cells and packs based on projects of my own that never came to fruition because of issues with making packs that i feel safe charging without the smart chip

Iron phosphate cells are much more tolerant of abuse and won't melt down like polymer RC cells. I'm not running any cell balancing at all in my battery, and so far so good, except for the time I left my interior lights on over the weekend and killed two of the cells. Prior to that I had left my lights on and completely drained the battery on two separate occasions, and just jump started the car. Contrary to popular belief, that battery isn't garbage if you drain it down.

Leaving a drain on it for two days is definitely not good though, but I changed out the two bad cells and it's been fantastic ever since. This winter has only been slightly below freezing but again no problems cranking. RPM sounds comparable to a stock battery, unlike a PC680 in winter.

 

[turboglenn]

Lowell, thanks for the clarification.. I have been using 3.6-4.1v cells mainly in parallel to make packs for my cameras and such so i can go out on filming sessions and not have to worry about only taping when i think it's gonna be somethign worth having caught.. with the cells i've been making it's nice because i can just burn tape constantnly (or memory card space now which is nice) and not worry about the cam booting fast enough to catch something or crap like that.. I've been running them al in P, and charging up to 4 of them on a universal phone and camera charger i modified usin wires and alligator clips i've got a borrowed lipo charger that i cna't figure out how to use but i would like to use it to balance all the cells when i take the time to read the manual i downlaoded for it

 

[lowell]

Only series packs need balancing, so if you charge them in parallel, they're already balanced nicely.

 

[ed1380]

Charging in parallel does not guarantee that they all charge evenly. Higher quality cells will have less variance but balancing every few charges doesn't hurt.

 

[lowell]

Just wanted to post up a 1 year update on the A123 cells and they're still going strong. I manually balanced the pack once, and haven't bothered again as they don't seem to need it. Daily driven all winter and never a problem starting. For the money I spent on PC625 and 680's over the years, I wish I had gone lithium much sooner.