Help with battery bank bus bars

[onahill]

The Trace 250 is fine between the inverter and bank, but you need a Class T on each series pair. In between the + terminal and the busbar. This would prevent one pair in series from discharging at high current into the other if a fault occurs in the other series pair. Note @chrisski has the Class T's in the proper location.

Anytime you put LFP into parallel strings each string requires a Class T.

Okay. Thank you.

 

[rodrick]

Check these out I’ve got one but haven’t put in service yet but maybe somebody’s got some experience here with themhttps://watts247.com/product/eq-24-2-24v-battery-balancer-balances-2-x-12v-batteries-in-series/

 

[onahill]

I'm sorry to be the messenger but a lot of folks just won't. I am not trying to be mean or anything but don't want to see you go down that rabbit hole when it can be avoided. Ultimately it is YOUR Pocket Book, Risk, Liability and the consequences over the long term, so it is entirely up to you. I've been here since the start of this forum and into solar etc (100% offgrid ++) for longer and it is a sad & terrible thing when someone burns up their battery packs for no good reason. BTW: I was a Heavy Lead (Rolls Surette battery bank) for years before joining the Bright Side of LFP.

Aside from selling the existing 12V packs, you can go a bit drastic, tear them apart and change them to 24V by combining the cells from 2 12V batteries so you have an 8S String with an 8S BMS. * THIS DEPENDS on if the Busbars are Welded or Bolted to the cells within the packs, AmperTime has used both methods in building their batteries.

The Victron will pull up to 125A to @ 24V and deliver 3000W + extra for surge handling up to 6000W or 250A draw.

I never thought you we're mean. I can really appreciate the experience you're coming from. I think my best step right now is contact AmpereTime. The batteries are under warranty, and I am following a 2S/2P configuration right out of their user manual for the battery. I will see what they say about this issue what they think I should do.

 

[onahill]

Check these out I’ve got one but haven’t put in service yet but maybe somebody’s got some experience here with themhttps://watts247.com/product/eq-24-2-24v-battery-balancer-balances-2-x-12v-batteries-in-series/

Looks promising. Thank you.

 

[chrisski]

Thinking on this, should the BMS trip on one battery, there’s now a 12 volt and 24 volt side.

I don’t know what happens. There’s a few possibilities I can think of, some failsafe, but I’ll what happens depends on BMS design.

Battleborn allows 4 batteries in series. Not all BMSs will allow batteries in series.

 

[onahill]

Thinking on this, should the BMS trip on one battery, there’s now a 12 volt and 24 volt side.

I don’t know what happens. There’s a few possibilities I can think of, some failsafe, but I’ll what happens depends on BMS design.

Battleborn allows 4 batteries in series. Not all BMSs will allow batteries in series.

I have messaged AmphereTime about this issue. We'll see what they say. Thanks again for your attention to my case.

 

[onahill]

So the bus bars are working well, and make working with the batteries much easier. I have installed mid point monitoring, as described in Victron's Wiring Unlimited, and now I can really keep an eye on voltage drift. I also installed one of the active equalizers, as pointed out by roderick. It is working great. Any difference in voltage after a day of charging and discharging is gone by morning. Thanks again everyone who put their time and energy into helping me.