Dr.Bass Steveo found 7s3p Module! Awesome Price!!

I have finally managed to source 24 of the JST S22B-AIT2G-2FS white A123 Pcb mount BMS male sockets on the 28S3P packs pcb's

I want to use them to plug straight into my own BMS without hacking about with the nice wires and BMS plugs on the packs.
I'll incorporate 8 of the sockets into some new BMS boards I am designing to fit into the A123 Oem location.

I am getting 24 so will have some spares. They are expensive but i can sell them at £7.00 + postage.

If anyone wants any PM me. Note they won't be here till begining of october.

Peter
 
Here is the BMS connector pinout dervied from my 28S3P packs. Each BMS board/connector supports 14 cell groups.

https://docs.google.com/spreadsheet/ccc?key=0AgpwHXS5JE6adHk0VkVEX1FjaTM4QzFRVmk2aXBaWnc
 
Just finished designing a drop in replacement slave BMS board to fit the 28S3P packs.

Based on my original BMS design but using newer pic and much reduced component count.

http://www.batteryvehiclesociety.org.uk/bvsorguk/forums/viewtopic.php?f=53&t=3379

Any BMS specific comments on the BVS forum thread please.
 
Has anyone done any load testing on the 7s3p modules? On average what are the quality of the cells like? internal resistance etc. Capacity testing and such?

or can link me?

Thanks
 
Just got my 2x 36 volt 20ah a123 packs from victpower and 2x bare cells with full tabs!

Pics show the pack that was badly damaged in shipping, the other pack was ok but slightly warped. The bare cells weighed in at 492 and 495 grams respectively.

Packs cost $343 with BMS and 3 amp charger cells cost $19 each

Will test on weekend...... how do you think the deformed pack will work?

Shipping cost $212 and the funny thing is the victpower rep told me two days ago that they are still waiting on the bare cells and then all the boxes showed up today???? So they didn't even have any idea that they had shipped out already. Took 16 days from placing order to getting packs and cells
 

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Hope they work out for you.

I inquired and was quoted 267 to ship one 16s pack to Colorado.

After seeing/hearing of the poor packaging and damage, I think I will explore other options.
 
Cell weight is good, mine was to around 490g. Bad Korean cells i got weighted 100g less. Check if your packs did not loose vacuum. If they smel nasty, they are punctured and need to be replaced.
 
Have you had a chance to test your 2 battery packs? I hope they work properly for you.

I'm thinking about buying a 36V20AH pre-assembled battery pack from Victpower. They now have a steel case for the pack which should protect the battery during shipment and could be mounted on my bike. They quoted me a good price: $285 for the pack with BMS, $33 for a 43.8V3A charger and $36 for the steel case. Shipping is $182.50 by TNT.

See my post under "Re: Victpower A123 20AH 48volt battery pack" for more details.

I would prefer a pre-assembled pack but I'm checking out all my options over Victpower.
 
raygo: Got one of the 36 volt packs on a bike with around 20 cycles now and no problems. Chargers are reliable, have nice quite fans, and don't get hot so far. They also make split packs, just got a 48 volt and 60 volt split pack delivered.
 
mikebikerad:

Glad to hear your Victpower battery packs work. Were you able to determine if the cells were new or salvaged? Also, any idea how the cells tabs were connected together? I want to be able to easily repair the pack if necessary.

I'm still undecided whether to do my own build or buy pre-assembled. ONS Power has a really nice pre-built pack with new cells for just slightly more cost than the Victpower pack. Waiting to get review from another ES member about to buy one.
 
Raygo:

Cells are soldered together with PCB like ping packs. They are nice big solder pools and the overall quality of construction is similar to ping except there was not any Kevlar protection sheets just duck tape but for half the price for a more energy dense pack no complaints. The assembly fee is so inexpensive but it sure is alot more expensive than the 7s3p modules.

I will go on a long ride right now and see where these BMS cut out. will report ah count.

Anyone have any updates on how many cells actually remain?
 
so, any of you, buying stuff from victpower, were able to pass these tests?
1. capacity >19.9Ah at 1C rate, 25°C
2. Internal resistance <1mΩ at 50% SOC and 25°C
3. bounce-back test at 0% SOC? Also called here on ES as "NASA test".
 
"1. capacity >19.9Ah at 1C rate, 25°C"

These cells aren't 20Ah cells and I don't know anyone who tested them to be that much, the tests I've seen done with them were around roughly 19-19.7Ah, sometimes mid 18Ah's too. Building a whole pack of them, I wouldn't consider them as being more than 18Ah to account for the worst cell. Of course you'd need to test what you receive and probably leave out the weak ones, which isn't really an option when you buy an assembled pack like these.
 
circuit said:
Nonsense. I have let many A123 20Ah grey market cells through my hands and most were spot on 20.0Ah.
Click to expand...

That is the first I've heard of it. Even the authorized distributors say 19.6Ah with a 18.5Ah minimum and since we are getting gray market cells I understand why it is possible to get even less than the minimum out of a cell or two in a large Fisker reject pack than what is stated by an authorized distributor that would be selling A grade for big bucks.
 
MN Driver said:
circuit said:
Nonsense. I have let many A123 20Ah grey market cells through my hands and most were spot on 20.0Ah.
Click to expand...

That is the first I've heard of it. Even the authorized distributors say 19.6Ah with a 18.5Ah minimum and since we are getting gray market cells I understand why it is possible to get even less than the minimum out of a cell or two in a large Fisker reject pack than what is stated by an authorized distributor that would be selling A grade for big bucks.
Click to expand...

Out of my 30 cells 6 were above 20ah, most at around 19.9 and 1 at 18.8, later bounced up to 19.3 after few cycles. To call them 19.5ah cell would fair.
 
cwah- i was actually thinking of doing just that - 30 lbs would mount in the rear rack of a bike np
vict is still selling these modules 283+ s/h which in my case is 170.00 US
it's totally possible but alot of work to reconfigure a pack into a 1p21s(if your lucky to get a good module with no bad cells) - it would involve using dremel to cut the tabs between cells- than drilling holes into the tabs sticking 10awg solid copper wire through them and connecting them -/+ in series.
i'd say it's easier to just buy loose cells and build a pack-also the modules are used so there's no telling how worn the cells are
 
I am actually wondering if anyone managed to directly use the bauer module directly on their bike? Put 4 in series and you have the right voltage. But it means 40kg of battery on a bicycle.

Anyone managed to do that?
 
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