diy solar

diy solar

Battle Born BMS hates my freezers

Bruceinfl

New Member
Joined
Mar 22, 2021
Messages
4
New to Solar but being assisted by an engineer buddy. Having a problem with what I think is a Battle Born BMS system. Trying to use a Battle Born 100AH battery to run a few freezers in my shed. Freezers average around 200 watts (at most). When multiple compressors turn on at once, the wattage spike will reach 750w or 65Amps for a split second. This should not be an issue for a BB 100AH battery connected to a Giandel 2200W Pure Sine Wave Inverter (using 1/0 gauge cables). Here is what has happened multiple times in my attempt to get this going:

When I turn on the inverter, BEFORE plugging in any load, the battery voltage tested by multimeter, and also on the inverter display, reads normally about 13.6v. As soon as I plug in my main freezer (69watts/hr), within 1-3 seconds and even before the compressor kicks on, the inverter gives off a tone and shuts down. I immediately retested the battery's voltage by mutimeter and it typically shows 2.5 - 7.0v after these failures. Sometimes after a few minutes, the battery voltage reading by multimeter returns to normal, showing 13.2-13.6v. Other times I need to use a charger to charge the battery enough to wake-up or reset the BMS. I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts.

I have attempted to rule out other equipment. I completely disconnected the solar charging side of the setup to strictly test the battery and inverter and it still failed. Originally I had a circuit breaker between the battery and the inverter. To rule that part out, I bypassed the circuit breaker, connecting directly, and the battery still failed, so it's not a bad breaker. All my battery connections are correct and my connections are tight. In order to rule out the inverter, my friend brought over his $250 Alibaba purchased LifeP04 battery w/ BMS (also rated at 100A continuos) and it worked perfectly without any issues. Max amps we saw was about 60-65. His Bluetooth app showed the brief spikes when plugging in the additional freezers and the compressors clicking on and off, but the inverter did not tone- and turn off. The Alibaba purchased battery and 2200 watt inverter ran for our entire half-hour test without any problems. After unplugging my BB battery for that test I tried one more time and it actually handled the load for about an hour before the inverter toned off again reading LO, although the BB still read 13.2v. Is this an overactive BMS ? Previously I had it hooked up and it ran all freezers for about 8 hours.
 
I think you are triggering the short circuit protection in the battery. I assume the test battery BMS may not me as strict. I believe you really should have 200-250 amps available to drive a 2200 watt inverter. Second BB is probably in order. Probably need it for run time anyway while the sun is down.
 
What is LRA (Lock Rotor Amp) of that freezer? The startup current of compressor can be from 3 ~ 7 times of running current.
"When I turn on the inverter, BEFORE plugging in any load, the battery voltage tested by multimeter, and also on the inverter display, reads normally about 13.6v. As soon as I plug in my main freezer (69watts/hr), within 1-3 seconds and even before the compressor kicks on, the inverter gives off a tone and shuts down."
Ddi you try some other load, I.E. 1000W Heater or hair dryer to see if you get the same result?
 
I think you are triggering the short circuit protection in the battery. I assume the test battery BMS may not me as strict. I believe you really should have 200-250 amps available to drive a 2200 watt inverter. Second BB is probably in order. Probably need it for run time anyway while the sun is down.
2200 watt inverter at 12V is 183A
 
It seems the battery is definitely suspect just from this test....you are sure the battery is charged?

I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts.
 
Call Battle Born tech support.

New to Solar but being assisted by an engineer buddy. Having a problem with what I think is a Battle Born BMS system. Trying to use a Battle Born 100AH battery to run a few freezers in my shed. Freezers average around 200 watts (at most). When multiple compressors turn on at once, the wattage spike will reach 750w or 65Amps for a split second. This should not be an issue for a BB 100AH battery connected to a Giandel 2200W Pure Sine Wave Inverter (using 1/0 gauge cables). Here is what has happened multiple times in my attempt to get this going:

When I turn on the inverter, BEFORE plugging in any load, the battery voltage tested by multimeter, and also on the inverter display, reads normally about 13.6v. As soon as I plug in my main freezer (69watts/hr), within 1-3 seconds and even before the compressor kicks on, the inverter gives off a tone and shuts down. I immediately retested the battery's voltage by mutimeter and it typically shows 2.5 - 7.0v after these failures. Sometimes after a few minutes, the battery voltage reading by multimeter returns to normal, showing 13.2-13.6v. Other times I need to use a charger to charge the battery enough to wake-up or reset the BMS. I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts.

I have attempted to rule out other equipment. I completely disconnected the solar charging side of the setup to strictly test the battery and inverter and it still failed. Originally I had a circuit breaker between the battery and the inverter. To rule that part out, I bypassed the circuit breaker, connecting directly, and the battery still failed, so it's not a bad breaker. All my battery connections are correct and my connections are tight. In order to rule out the inverter, my friend brought over his $250 Alibaba purchased LifeP04 battery w/ BMS (also rated at 100A continuos) and it worked perfectly without any issues. Max amps we saw was about 60-65. His Bluetooth app showed the brief spikes when plugging in the additional freezers and the compressors clicking on and off, but the inverter did not tone- and turn off. The Alibaba purchased battery and 2200 watt inverter ran for our entire half-hour test without any problems. After unplugging my BB battery for that test I tried one more time and it actually handled the load for about an hour before the inverter toned off again reading LO, although the BB still read 13.2v. Is this an overactive BMS ? Previously I had it hooked up and it ran all freezers for about 8 hours.
 
It seems the battery is definitely suspect just from this test....you are sure the battery is charged?

I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts.
If I am certain of anything, I'm certain its charged. It was charged with a 60Amp charger recommended by BB and it was also topped off by my panels. Somehow BMS is triggering.
 
What is LRA (Lock Rotor Amp) of that freezer? The startup current of compressor can be from 3 ~ 7 times of running current.
"When I turn on the inverter, BEFORE plugging in any load, the battery voltage tested by multimeter, and also on the inverter display, reads normally about 13.6v. As soon as I plug in my main freezer (69watts/hr), within 1-3 seconds and even before the compressor kicks on, the inverter gives off a tone and shuts down."
Ddi you try some other load, I.E. 1000W Heater or hair dryer to see if you get the same result?
When the compressor kicks on it goes up to 60amps for a split second but thats within BB capabilities to my knowledge.
 
I think you are triggering the short circuit protection in the battery. I assume the test battery BMS may not me as strict. I believe you really should have 200-250 amps available to drive a 2200 watt inverter. Second BB is probably in order. Probably need it for run time anyway while the sun is down.
I agree with part of that. I actually have 2 batteries on a boat from China right now but was using the BB as a test and it will be used for something else. That reminds me that I used the BB to run a window AC for 4-5 hours and the amperage on that was higher than the freezer for sure.
 
If you're willing to invest $40-50 or so get a 2-3F supercapacitor and wire it parallel with your battery bank. That'll feed any conceivable surge that the inverter could ever pull without destroying itself.
 
"Trying to use a Battle Born 100AH battery to run a few freezers in my shed. Freezers average around 200 watts (at most). When multiple compressors turn on at once, the wattage spike will reach 750w or 65Amps for a split second."

The freezer that broke the battery's back.

It may be able to start one freezer at a time, and start one when a few are running, but starting multiple at once is asking for a lot.
One 50 Ah lead-acid car battery can put out about 800A (at 7.5V, a bit below what inverter needs.) Lithium battery has lower internal resistance.
BMS is what is limiting the current. If BMS controlled an external contactor for over/under voltage and didn't try to limit current, it would have a better chance.
 
I think @Bud Martin is on the right track by asking about LRA.

I haven't seen inrush current otherwise mentioned. A current spike on a display is likely notably lower than the actual inrush current. "MAX" on a typical clamp ammeter won't cut it. You need an INRUSH function.

I suspect the inrush is exceeding the 100A limit and causing the BMS to trip.

+1 to @Bud Martin's suggestion to try it with a resistive load.
 
I thought he did test with a resistive load......

"I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts."
 
I thought he did test with a resistive load......

"I simplified the test by only plugging in two light bulbs instead of a freezer. You can see that the voltage is 99% to start until I turn on the inverter and immediately it tones off and the voltage on the battery reads 7.0v. From (2) light bulbs totalling 210 watts."

Thanks. Missed that. Time to call Battleborn.
 
I bought two BB 100AH to use in my trailer with a Samlex EVO inverter rated at 2200W. The BMS in the Battle Borns is not fooling around when it comes to strictly limiting current. For testing (only one battery) I hooked up a 700W heat gun to the inverter output and that worked well. Next I tried a cheap-o Harbor Freight grinder with a 1/4 HP motor. Just triggering the motor switch instantly shut down the whole system. Motor loads have ridiculously high peak starting currents.
 
I bought two BB 100AH to use in my trailer with a Samlex EVO inverter rated at 2200W. The BMS in the Battle Borns is not fooling around when it comes to strictly limiting current. For testing (only one battery) I hooked up a 700W heat gun to the inverter output and that worked well. Next I tried a cheap-o Harbor Freight grinder with a 1/4 HP motor. Just triggering the motor switch instantly shut down the whole system. Motor loads have ridiculously high peak starting currents.

Did it work with both batteries in the circuit?
 
When the compressor kicks on it goes up to 60amps for a split second but thats within BB capabilities to my knowledge.
how are you seeing the 60amp peak? LRA only last for a milliseconds most meters can't read the true inrush.. but max is over a longer period so it averages to a lower reading
 
Back
Top