I am removing the Li-ion 48V Bigbattery.com pack from my recommendation list


making mistakes so you don't have to...
Perhaps "stupid comment" but can't you just use the holes in the BMS to attach the new wire with M4 bolt and nut?

Sure, soldering beats any lug.
Depending on wattage of the soldering iron and the experience of the person wielding it..
(Too low wattage (and mass of the tip) will heat up the entire board and not just melt the solder)
A lug and bolt/nut might be the easiest way.

Seeing "quick fix" solution like this...
Really bad.
For Chinese companies it's more "normal" as they don't have to follow safety regulations.

BB is American company, yes?
I don't know about customer protection in the USA, in Europe a factory can write what ever they want, but still need to follow the EU law.

That means a washing machine factory might say one year warranty, but it's expected lifetime makes 3 or 5 years more reasonable.

Hard drives have 3 years, CD players, 3 years etc.

It doesn't matter what the factory likes, it still needs to live up to expectated lifetime.
As they made 10 year warranty, any court in EU would set minimal 5 year warranty.
Unless it's sold and bought as "B choice, at own risk" clearly described in the description of the product.

Bud Martin

Solar Addict
Thank you, thank you. You've saved me a lot of research!
I would ask BB to send you new BMS board with wires already properly soldered well to the board, if you do not have proper soldering tools and good experience with soldering, especially with large wire, I would not suggest you to do the work, cold solder joint can be dangerous due to the joint will heat up and burn the board.
BB should own up to it and make it right for selling products with poor quality workmanship.
Luckily we have some people that do the good test to find out about the poor qulality workmanship, you would think BB will have proper tools to perform QC.
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New Member
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New Member
This is one manufactoring inside display. Clean and tidy, high quality, test report outperform the counterpart.


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Photon Sorcerer
@adunsulag that looks like one side of your Anderson connector just popped out and should click back in.

No soldering necessary if I see what I think I see in your picture.


Photon Sorcerer
See here at about 1:30 into the video:

Don’t worry about the handle part in the video, that’s an add on.

Just happened to be the first helpful video I found.


New Member
@JoeHam Unfortunately its just a hair too short to actually click in with where the sb50 is screwed in at. I've attempted multiple times to push it back in and the wire is just barely not able to make it. I'm not able to get a new board but they are sending me new wires. I think before I attempt to deal with re-soldering, I'm going to try and unscrew the connector from the case, push the wire in and then see if I can drill new holes to mount the sb50 connector 5-10mm back. It means the connector won't be flush with the case, but I think it might still work. I'd prefer that approach than having to replace the wire.

I built some nifty sb50 disconnects out of a sprinkler T-joint that won't work with the connector being farther back in the case, but that's fine if I can at least get the thing to connect.