What to do if your Battleborn battery's go dead when you connect your big inverter

[ebdesroches]

Just recently saw Wills thread on how to connect a big inverter with big caps inside to your battleborns. I didn't know that then and all 8 went off line. Just connect a 12v battery to each EXCEPT last one in series....last one in series use a power resistor to charge....see Wills tootytorial!

Battleborn says what I did could ruin the BMS. I think I got away with it this one time....and maybe Will got away with it....take a look at his scared terminal.

 

[Will Prowse]

Which inverter and what voltage battery bank?

 

[ebdesroches]

Lv5048, 4x series, 2p....8batterys total. 12volt charger on each to resuscitate

 

[ebdesroches]

Lv5048, 4x series, 2p....8batterys total. 12volt charger on each to resuscitate

48v

 

[ebdesroches]

Battleborns

 

[Will Prowse]

Yep. That'll do it.

 

[ebdesroches]

Ended up buying buying battleborns surge suppressor: Csl500 model. I did that so that each time I disconnect the batteries or breaker is tripped I won't have to parallel a battery charger to each open battery to get them online again.

 

[ebdesroches]

Testing phase is next: Will it work repetitively? Soon as I get a better charger for standby in case it doesn't work and batteries disconnect. Old battery charger croaked

 

[Will Prowse]

With that module, yes sir. Repetitively as much as you want

 

[ebdesroches]

Yes...it should but as with everything else ....sometime things don't work like they should.

 

[erik.calco]

@Will Prowse To be clear, there are criteria when the resistor isn't enough and could damage the BMS? If so, under what criteria is the resistor method safe?

I have a 30 ohm 50W resistor I was planning to use on a 2S2P 24V of Lion Energy 90aHs (UT 1200s) with LV2424 as early as tomorrow. Just balancing the batteries today.

 

[ebdesroches]

Battery can at least stand 200amps for a half second.

By ohms law 50v/ 0.25 ohms gives you 200amps ....I would imagine that anything bigger than say 1ohm would work. Of course bear in mind that you could burn the resistor up if it doesn't have enough wattage to withstand the surge energy. Also you should only charge the caps up and not let too much normal load power heat up resistor.

I have experienced the lv5048 not working out so well because caps get discharged too fast....even with unit switched off...so the surge limiter I believe is what I need.

 

[BruceNewEngland]

WOW! Taking out eight brand new Battleborns would’ve been devastating...

Glad you were able to recover, and thanks for sharing.
Bruce

 

[ebdesroches]

I figure that $280 for the surge protector beats chance of wrecking about 8k of batteries!

 

[ebdesroches]

@Will Prowse To be clear, there are criteria when the resistor isn't enough and could damage the BMS? If so, under what criteria is the resistor method safe?

I have a 30 ohm 50W resistor I was planning to use on a 2S2P 24V of Lion Energy 90aHs (UT 1200s) with LV2424 as early as tomorrow. Just balancing the batteries today.

Battleborn says use a surge suppressor for inverters over 4kw. I think yours is 2kw? Anyway using a resister is the civilized way to do it....as long as the caps in the inverter don't discharge too fast.....remove all loads from all in one

 

[ebdesroches]

I rather suspect if it's an all in one the unit itself requires battery power....which will drain your caps and make the resistor charge of no use.

 

[ebdesroches]

If you have only an inverter you are connecting a resistor may work to charge caps.

 

[ebdesroches]

Again this is exactly what Will showed us how to do.

 

[erik.calco]

@ebdesroches very good to know! Mine is 2.4kw. As for the drain, is this because you are disconnecting from the batteries? The drain shouldn't be an issue as long as it has batteries and AC-in at all times, I would think.

 

[ebdesroches]

Yes problem is when you first connect or reconnect the battery. You may still experience battery internal disconnect....if you do use a 12v charger on each affected (measure voltage).