Recent content by Ktraughb

I am going to do a very controlled test on a 12v system of charging a 4s1p setup of CALB 40ah cells. I actually want to test this with the possibility of alternator charging (in parallel to an agm battery). I am well aware there are commercially available batteries to do this right off the...

No, I understood what you meant. I just didn't convey it well in my last post.

So I spoke with the seller today. He is a middleman that actually bought them directly from the pdf posting you gave me. Interestingly, when I mentioned someone told me they were bulk charging these with success he finished my sentence with "until he burns his house down." He exclaimed again I...

True, but if one cell fails it will have to be de-soldered, replaced and balanced and re-soldered into the pack. Would a fresh cell affect the overall stability of an individual pack?

Do you think the modules I posted in question by hymotion would be susceptible to imbalance issues? I know a 4s module with the calb cells would be simple to check voltage on often. Not so simple without pulling the a123 module apart and adding individual lines. Thoughts?

Hmm. A heated debate with two very opposing opinions. Seems to be a decent amount to of data to support both. I may risk it, and while I'm new to lifepo4, I'm definitely not new to electronics/electrical projects. I realize I may risk the cells, but I intend to charge these as described...

Wow evtv has a fantastic write up on exactly the things I've been researching. Thanks so much for that link. Very informative. And I never thought about replacement. You're right, original a123 are hard to come by. That seller owns them all now. Lol. It appears calb continues to release...

Thank you, sir. Its actually refreshing to hear someone else doesn't like a bms. Good to know. Again, I think for ease of maintenance, I may go with calb cells over the a123. I know for a fact they'll survive the amp burst I'm looking for. And it won't be so difficult to charge between...

If I do decide to use 4 calb cells in series... Is there any issue charging them as a 12v module with a 12v lifepo4 charger? Should I use a 3.6v and do each cell alone?

(Edit): As for cheap HK lipo, I suppose that's an option. I'm not a fan of lipo for safety reasons, but those could also be easily overcome in this application with a fireproof box. It may not have the same versatility and will not have the same level of safety as the A123 pack though. Maybe...

My thoughts exactly. I know they can be custom built.. But not cheap. Most bms I've seen have protection at much lower amperage discharge.

not sure how, but i totally skipped this post. That is so awesome you have a pdf of the original data on these batteries. That is very handy. Definitely food for thought toward making my decision. Also, it appears the sense lines have been removed or were never installed in these packs. If I add...

I do something called dB Drag racing. Basically car stereo competition measured in sound pressure level. You may have heard of it seen/it. My system consists of an 8kw amplifier. In reality the starting rate is usually about 6kw, and dependent on voltage drop and impedance rise the amplifier...

so youre saying theyre good, huh? worth the bms and $? Even though theyre a couple years old? Put it this way, I will never fully discharge these things (so i hope) and the discharging i do will occur a maximum of probably 100 times this year. so basically a 400 amp draw for ten seconds, at most...

he says he acquired them in the bankruptcy of the company. he may not have actually produced these. not sure. he did say he could build a bms for it for $200 and it will supposedly be good enough for a standard 12v automotive charger. Of course with shipping im at $500 at that point. Which isnt...