How are your A123 20ah packs holding up ?

[999zip999]

Asking for an up date on the pack builds with A123 20ah pouches. Is everyone happy ? Please tell if full or half tabs.
My 24s pack full tabs from the JRHolmes group buy is great at 30amp and get 17.99ah before I shut it down. It was well balance till one cell ran high 3.8v the others 3.5v and it shut down my 1420 charger so used my spare cell today. Will see how it goes. Has any body had to replace a cell or more ?

 

[arkmundi]

My 12S pack needed two cells replaced, failure unknown, but I've speculated on my saga thread. Before and after, the pack has been performing well. Latest cell data show the pack well balanced at around 3.3 to 3.4 volts and all +-.5 volts of the average. The pack charges in no time, comes up to capacity and does not sag at all. After a daily run in which I use perhaps 25% of rated capacity, the cells are sitll in balance. So I'm happy, for the moment.

 

[999zip999]

The pack seems fine now. the one cell I replace seems soft and fixable. Not like the others. Not a puffer.

 

[ohzee]

First i built 2 12s packs using compression and had them in series with cell_man high power BMS. did not use it that
many times , but I had 1 cell in center expand so much I had to cut it out and replace it.

Tore those down and built a 20s battery with a ping high power BMS using compression & blocks aluminum/plastic.
This battery has performed flawless and is the battery I have used the most.

built a 24s pack with agniusm's awesome kit and hooked it up to a evaessemble high power BMS tht was a custom order.
This thing has also worked flawlessly to date with no issues. It's on my cargo bike and the 20s pack is just used as a
backup if i somehow empty the 1st one.

I now have about 7 extra a123 cells.. considering building another 24s tearing apart my 20s or keeping it as is.

So far out of almost 60 a120 20ah cells I have bought all somehow thru vic I have only had an issue with the 1 that for reasons unknown
just expanded itself to all hell. I am very happy to date.

I did also short out one cell when I was building the last battery which resulted in only 3/4 of one tab being vaporized.. my own fault.

 

[999zip999]

Ohzee how did you build the 20s pack and did you use short tabs cells on either ? Yes Agniusm buss boards looks clean which gives value to the build. Plus I did drop a metal ruler on the tabs and too saw sparks. That's why chops sticks or plastic is best ect.

 

[ohzee]

20s is compression like someone else on this board posted.. using the blue plastic and aluminum blocks.. worked pretty good , but not real pretty.

All normal tabs never had any short tabs.

 

[999zip999]

O.k. the drutledge build love mine too. When you said compresssion I thought of the whole pack under compression. Like how did he do that.

 

[docnjoj]

OK so I built my agniusm 6Sx2 pack, cycled the cells 1x and charged to 3.55 volts. It has sat for about a month since my current Ping pack continues to work fine and I can do our 20 or so miles a day. Since my wife lost her job and is working from home now, we have ridden almost every day for the last month and a half. Less money but much better health. Oh yeah, the A123 pack sits at................3.55 volts per cell. I am going to encase it in a hardboard shell this week with a wrap of fillament tape and overlay of Gorilla tape and start to use it next week. Also I will use my parchament paper between the cells. Give the Ping a rest.
otherDoc
edit: all long tabs

 

[drutledge]

So far my aluminum block and blue plastic compression pack is going strong (14s). I managed to short out two batteries by not paying attention when building it (vaporized the tabs in a most spectacular fashion) but no problems since. I use the cargo bike it's in a few times a day and charge it each night off of my solar battery bank.

No BMS and I stopped hooking it up regularly to my Celllog 8s since the damn cell logs themselves were starting to throw the balance off. I've also seen a few celllog 8s I have do funky things like invert the text on the screen. I feel safer with them off and only checking once a week or so. So far about 13mv out of balance for the whole summer. No puffers or other problems. The cells themselves are compressed with the red garolite and some spring steel in between the sheets to even out the forces. I like the 'see-through' design this offers.

 

[999zip999]

Drutledge I don't under stand how you did the end terminals under the secret shrink warp just want to cut it open for a small look. Good you got the compession on the pack thing.Looking good 14s as you use a1420.

 

[drutledge]

Stripped 10AWG wire about 1 1/4"
Placed into copper sheet, maybe 1 1/2 x 2" in size.
Folded sheet, wire is in fold. Tapped well with hammer.
Put heat shrink tube over the whole thing. Made it slightly longer than needed and clamped heat shrink while it was still hot to seal it all around.
Made a slit in bottom so I could slip it over a cell tab.
Slipped copper over tab, bolted it in place with large washers on outside of heat shrink and balance wire on outside bolt end.
Slipped another heat shrink on to seal bolt and ends from outside world.

The wire is in there good enough that I can't pull it out with my two hands.

 

[Rollodo]

Hey, sorry if a little off-topic but just a quick question - a two-pack A123 16S1P 52.8V 20Ah custom setup from Cell Man for ~$750 plus shipping - a good deal? By a two-pack I mean the whole battery split into 2 parts for hanging on the bike (it's still a 16S1P setup, looks like a 8S x2).