ShunBin Battery Packs: 12V/24V 100AH and up ! A Complete RIP-OFF ! AVOID

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
As stated before, I was sent a replacement BMS. The positive terminal would still get incredibly hot using my solar setup or the charger. SHUNBIN sent out a 3.6v charger to test every cell. Every cell was able to charge to 3.3v without any heat. I have no idea what to try next. Is there a plug and play BMS that might work? Could it be the + - terminals from the cells to the box exterior? Next time...I'm talking to Steve S for the next solar setup.
I'm not sure what exactly you are asking here.
 

Stiffmeister

Solar Enthusiast
I have a $2000 battery I don't know how to troubleshoot. Each cell charges to 3.3v. But when connected to solar the positive terminal burns my fingers. Already swapped with replacement BMS of SHUNBIN. Maybe buy a Chargery BMS? I don't want to be out $2k. Just messaged SHUNBIN AGAIN. He asked if it charged/discharged correctly. Well dude read out messages for the past year!!! Is he forgetting? Do i ask for a 3rd BMS replacement?
 

Supervstech

Administrator
Staff member
Moderator
I have a $2000 battery I don't know how to troubleshoot. Each cell charges to 3.3v. But when connected to solar the positive terminal burns my fingers. Already swapped with replacement BMS of SHUNBIN. Maybe buy a Chargery BMS? I don't want to be out $2k. Just messaged SHUNBIN AGAIN. He asked if it charged/discharged correctly. Well dude read out messages for the past year!!! Is he forgetting? Do i ask for a 3rd BMS replacement?
Take pictures and post them here of your setup, and the charge controller connection place, and the charge controller settings.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
The pack I got also had the one cell terminal get hot, even burnt the fiberglass. Photo's on Page 10, Post 191.
I wound up tearing the ShunBin mess apart and converted it to two 175AH simple Straight 8S packs, each with a QNBBM-8S and Chargery BMS8T. The original BMS was attached to the end (neg) cell directly and one 1g wire to the Neg Battery terminal from the BMS, the POS was just a cable from the cell to Batt Terminal which is the one that burnt.

I'm sure you rechecked your connections and bolts to the busbars & cables are all tight. If they are maybe it need to take the busbars off, clean everything thoroughly, busbars surfaces, the contact areas on the cells etc and put it all back together and see. I can't speak to the Dumb BMS they used, I tossed mine because not only did it look like a 5-year-old soldered it with a blowtorch it was a "dumb" BMS and I wasn't having any of that "blind use" nonsense as the cells were not behaving. I initially put a Chargery on the original configuration and that showed me how wonky the cells were, that's when I decided to break it up into two packs.

This works but is NOT optimal either because these two live next to 2x 280AH packs (3rd one in the works) and the 105AH difference in capacity presents issues while charging as the 175's reach full and tickle HVD (Hi Volt Disconnect) and start cycling on/off while the 280's are still charging. The Gotcha, is that if the 280's are not charged to the same voltage (SOC) because they take more when charging completes the 175's will dump to the 280's (they are all in parallel). I'm now considering redoing the 2p8s with these as 70AH capacity difference is better than 105AH and should help with keeping things more even.

2x-175AH-8S with QNBBM-8S.jpg
 

Stiffmeister

Solar Enthusiast
Well i had another SHUNBIN BMS take a crap. Once again, a battery will not charge. So I have five SHUNBIN 500ah batteries and only three work. Going to come back to the US and order quality BMS to replace them all. Chargery or Overkill? Any suggestions? Can I purchase more of these cells that were in the SHUNBIN cases? I'm not sure if they were 280ah or 272ah.
 

mandrews44

Solar Addict
I have 2 400ah shunbin batteries and I replaced all of the BMS's with Overkill. I don't recall your voltage, I'm sure he either has or can get 12v or 24v. The one I used the 12v 120A version and it is working great. Between using the Overkill BMS and an active balancing addon, both are doing well.
 

Stiffmeister

Solar Enthusiast
I have 2 400ah shunbin batteries and I replaced all of the BMS's with Overkill. I don't recall your voltage, I'm sure he either has or can get 12v or 24v. The one I used the 12v 120A version and it is working great. Between using the Overkill BMS and an active balancing addon, both are doing well.
Thank you for the reply. I have five 12v 500ah. Technically I have four wired in series for 48V paired with an Outback Power FlexPower 2 inverter and two Flexmax 80 charge controllers. So I will go with five Overkill BMS...but what is the active balancing addon?? I just watched Will Prowse build a small eight battery pack battery with the Overkill BMS on YouTube.
 

mandrews44

Solar Addict
Thank you for the reply. I have five 12v 500ah. Technically I have four wired in series for 48V paired with an Outback Power FlexPower 2 inverter and two Flexmax 80 charge controllers. So I will go with five Overkill BMS...but what is the active balancing addon?? I just watched Will Prowse build a small eight battery pack battery with the Overkill BMS on YouTube.
You might want to make sure the BMS that you use is setup to support serial to 48 volts. Most BMS's I've seen will not handle more than 2x stated voltage in a series configuration. This might be why the BMS's are no longer working. If I was building a 48v system, I would not put 4 12v packs in series, I'd use a 48v BMS and a 16s5p (using 100ah cells) for this. From what I've read, 4 12v packs in series does not work.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
Well i had another SHUNBIN BMS take a crap. Once again, a battery will not charge. So I have five SHUNBIN 500ah batteries and only three work. Going to come back to the US and order quality BMS to replace them all. Chargery or Overkill? Any suggestions? Can I purchase more of these cells that were in the SHUNBIN cases? I'm not sure if they were 280ah or 272ah.
First, you have to find out the make/model/version of LFP cells you have. It was not easy to figure out mine with the scratched off numbers and Shunbin would not volunteer anything. I would not bet on being able to get similar cells.

The BMS' really does depend on how you are going to use these packs.
I have five 12v 500ah. Technically I have four wired in series for 48V
TBH, I don't know of BMS' that will allow for that, 4x12V in series... nope.
Honestly, you'd likely be better off tearing them apart and converting them to a proper 16S/48V with 16S BMS running the show. That of course would depend on IF the cells are all the same or now, there's a 50/50 chance they may be.

I KNOW this is not your favoured plan, I get it. It pained me greatly to have to tear apart that nice cased battery assembly with my 24/350 which I split into 2x 24V/175AH packs. But now Ironically, I have to put that back together as a 350 going back to paralleled cells because the 105AH difference between my 280AH packs and the 175's is causing me grief where 70AH difference will lessen that a lot.
 

Stiffmeister

Solar Enthusiast
SHUNBIN say's they have an improved BMS now. Ugh. I have been using the batteries for months no problem. For sure next time I build my own battery bank.
Yes, we have improved the BMS, the battery can support parallel or series now, do you want to try to order the new version 2 pieces to series? please check the attached BMS picture
 

mandrews44

Solar Addict
SHUNBIN say's they have an improved BMS now. Ugh. I have been using the batteries for months no problem. For sure next time I build my own battery bank.
Yes, we have improved the BMS, the battery can support parallel or series now, do you want to try to order the new version 2 pieces to series? please check the attached BMS picture
While it might be improved and permit 24v total, most circuit designs I've seen at best use 2x max design voltage. Even with a BMS that states it handles series, they all have max voltage limit on the mosfets. Typical is 30 volts. They may work for a time at 48v but I'd imagine their days are numbered. The battery where the + output is passing 48+v through the mosfets.
 

Stiffmeister

Solar Enthusiast
So are you you saying pull all cells out and get a 48v BMS? Which BMS is best...Chargery? I saw the Overkill which sells for over $100 and yet it's only $70 on Alibaba (same bluetooth, etc). I haven't drawn more that maybe 1500 watts on this with a coffee pot. One of the SHUNBIN batteries never worked in the first place.
 

B.Rad

New Member
I have been using two12VDC 500Ah Shun Bin batteries to power the house side of my RV for a few years. They have performed as well as any of the CALB or Battle Born I have. The only bad thing I can say is that after load testing the batteries are more like 400Ah, 834Ah for the two in parallel. Still a great deal at $4.90/Ah. Upgraded the house power converter/charger to LiFePO4 as well as added a DC-DC LiFePO4 charger to the alternator charging circuit and use an Outback FM80 CC.
 
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