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Any way to reset BMS on parallel batteries without unparalleling them?

corn18

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Looking for a way to reset 2x12V SOK 206Ah LFPs in parallel. I do a lot of playing around with load testing and what not and every time I trip the BMS protect, I have to unparallel my batteries, apply power from the SCC to each one individually and then reparallel them. PIA. And sometimes I trip the BMS without meaning to and again, PITA to reset each one. And there is no way my wife will be able to reset them if I am not with her, which has happened.
So, any thoughts on how to get these suckers to reset without getting out a tool kit?
 
The only time one of my BMS "tripped" was when I did something stupid. Once I corrected my mistake I pulled the balance lead connector out of the BMS and it reset when I plugged the connector back it.

In the normal course of use, someone would have to do something purposely nefarious to cause my BMS to trip. In saying that, I'm lost on how you're tripping your system so easily.
 
if the system were powere down, do you think an adjustable DC 30 volt 10 amp across the battery leads would do the trick?

For my BMS resets, they were overcurrent from the SCC to the battery and hat simply meant removing and reapplying the solar panels. Flip of a circuit breaker in my case. Your procedure is obviously different..
 
Any time batteries are set up in series or parallel you will eventually have imbalance issues. My advice is to have access to connect a charge device to the terminals of each individual battery.
When the batteries get imbalanced to the point they effect system operation, remove load from system and individually charge each battery to full. (you don’t need to disconnect batteries, just ensure loads are zero)
You can use the existing SCC for this in the case of parallel batteries, but need to charge series batteries at their individual nominal voltage.
 
The only time one of my BMS "tripped" was when I did something stupid. Once I corrected my mistake I pulled the balance lead connector out of the BMS and it reset when I plugged the connector back it.

In the normal course of use, someone would have to do something purposely nefarious to cause my BMS to trip. In saying that, I'm lost on how you're tripping your system so easily.
I replaced my SOK non bluetooth BMSs with their new bluetooth BMSs. I thought they were identical except for the addition of BT. Well, reports came out that they had different current limits, so I wanted to test that. That requires load testing. Turns out, they are very different. Every time I run a test to see where the discharge/charge limits are, I have to go through the reset procedure. I can live with that.

The real problem is when I am boondocking at night. I go to the store to get something and my wife wants to make some coffee and toast. She forgets that I told her you can only run one big ticket item at a time and poof! no power to the camper. None, zip, notta.

If there is solar, she can turn off the main battery switch and turn it back on and one BMS will reset and power is restored. But wiat, she forgot to press the precharge button, so both batteries are still inop. Then she remembers she needs to push that magic red button so she turns off the batt switch, pushes the button, turns on the batt switch and still nothing. She hates my system and wonders how this is an improvement over the factory setup. Valid question.

Here's the scenario that happened to me. Trailer was hooked up to 50A shore power. Had both air conditioners running. Getting ready to leave and I flipped off the 50A breaker at the shore power pole. The system tried to switch to battery power and the BMSs tripped. No power.

So, I am looking for a way to reset a BMS that is easy and preferably automatic. An A-B-Both switch is great if the sun is out.

Better yet, who makes a BMS that resets itself? I would gladly install those to replace the SOK BMSs.
 
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In my system, I think the inverter will trip on overcurrent before the BMS on the batteries does. Can you set your inverter to draw fewer amps from the batteries than the BMS are willing to produce?
 
In my system, I think the inverter will trip on overcurrent before the BMS on the batteries does. Can you set your inverter to draw fewer amps from the batteries than the BMS are willing to produce?
Maybe. It's a Victron Multiplus II 12/3000 12x2. I'm sure it has a setting somewhere for that.
 
I decided to take the first step. I bought a Blue Sea Systems 1,2,1+2 battery cutoff switch. This will allow me to connect each battery individually or parallel. I can use that and the SCC to get both BMSs reset. Or the truck with the DC-DC charger. Parts will be here tomorrow and I will report back.

DC wiring 290RL rev 1 b.jpg
 
Got the 1,2,1+2 switch installed. Works a treat. I forgot to hook up the precharge and turned the batteries on and the first one went into protect. So I set the switch to that battery and the solar reset it. Awesome sauce! Now I need to build my little boost pack with the buck converter so I can use that when the sun don't shine.

DC wiring 290RL rev 1 cubby.jpg
 
I got the little boost pack set up with a buck converter. The boost pack is Li and puts out 12.56V. The buck converter output is set to 14.6V which should be plenty to wake up the BMSs if the solar is not working. I may wire this into the system with a momentary switch on the output to the 1,2,1+2 switch to easily reset the BMSs.

IMG_5239.jpgIMG_5240.jpg
 
I got the little boost pack set up with a buck converter. The boost pack is Li and puts out 12.56V. The buck converter output is set to 14.6V which should be plenty to wake up the BMSs if the solar is not working. I may wire this into the system with a momentary switch on the output to the 1,2,1+2 switch to easily reset the BMSs.

View attachment 93949View attachment 93950

So did this work to reset the BMS ?
 
I just ordered a converter. I'm going to wire it to the RV tongue battery and set it's output to 28VDC. I'll put a pushbutton in series with it so I can pulse the BMS units to see if that will wake them up.
 
Got out to the trailer and turned on the batteries without precharging. Both went into protect. Used the boost pack with the buck converter and brought them both back to life. So that works.
 
Got out to the trailer and turned on the batteries without precharging. Both went into protect. Used the boost pack with the buck converter and brought them both back to life. So that works.

Did you have to disconnect them from each other?

EDIT - Just saw your other post regarding the 1,2,1+2 battery main switch. Sorry.
 
Here's my first cut at wiring in a reset system.

I have a DP3T toggle switch that is on-on-on.

In the center position, it connects the + batt buss to the charge input on the boost pack. This is the normal state where the boost pack is charging. The output of the boost pack is not connected to anything.

Up position provides 14.6V from the buck converter to the left battery. This position also disconnects the charge input. This avoids a do loop where the boost pack tries to charge itself.

Down position is the same as up but connected to the right battery.

I have to set the main batt disconnect switch to off in order to do the reset. Otherwise the loads will overpower my boost pack and draw the voltage down below reset level.

I will give this a go to see if it works. I gotta say, these new SOK BT BMSs are much more finicky than the originals. Breath on them funny and they go to sleep.

Will report back once I have this hooked up. I might house it all in one box with the inverter precharge (another BMS work around).

DC wiring 290RL rev 1 boost pack.jpga
 
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