Thoughts on a 48V Lithium Battery that won't broadcast Bluetooth?

[TobiasFunke]

For you incredibly talented battery minds out there...

I took a chance a bought a 48V 100ah BMS Bluetooth battery from an auction closeout site (Amazon returns). Paid next to nothing for it, was pretty excited, as it is time to switch out my lead acid batteries in my Yamaha. Upon receiving the battery, I noticed the following:
- It had a charge
- It would take a charge (although I didn't leave it on long)
- But, the bluetooth broadcast from the BMS can not be found anywhere

And I've hooked up to BMS bluetooth before on other batteries, so I don't believe this is user error on my end.

I could, of course, tear this thing apart, disconnect the existing BMS and attach a new BMS on. However, before doing so, my question is... is there any risk of using it as-is?

I'm not too concerned with the bluetooth functionality, and someone has tried to convince me a faulty BMS would cause the battery to not charge at all. Any thoughts?

Thanks in advance!

[jasonojordan]

Not every BMS has Bluetooth. Its very common for budget batteries to cut corners with cheap BMS units that do not have Bluetooth.

Heck even what I would call middle of the road price point batteries like my Big Battery Falcon Elite does not have Bluetooth from what I am told...

(although I suspect they are lying since I get a broadcasted Bluetooth id but can't find an app that works with it but thats a rant for another day)

[ojo]

You could try with the Overkill Solar app or the Xiaoxiang app, both to be find at App Store / Play Store!

[TobiasFunke]

Thank you both. The issue is less about the bluetooth broadcasting. I can confirm this is a bluetooth connected battery, but have tried multiple apps and none detect a bluetooth signal from the battery.

My bigger question is it is safe to use this battery? If I can't see that the bluetooth is working, how do i know if the BMS is any good?

And what would be the harm in using it? I only have about $100 in this battery, so I'm not really worried about any really long-term damage. I just want to make sure nothing bad happens, like self implosion

Thoughts?

[TheCartBoy]

Without actually testing all the protection mechanisms yourself, you won't know. Did just the Bluetooth controller fail, and the main microprocessor is still functional and doing BMS stuff? Is it an all in one chip and it's partially corrupted? Your guess is as good as mine.

[TobiasFunke]

Originally Posted by TheCartBoy

Without actually testing all the protection mechanisms yourself, you won't know. Did just the Bluetooth controller fail, and the main microprocessor is still functional and doing BMS stuff? Is it an all in one chip and it's partially corrupted? Your guess is as good as mine.

Which means I need to pull this battery apart?

Here is what it is: https://www.lossigy.com/Products_details/15.html

[ojo]

The Bluetooth of my JBD BMS turns on on demand. You've to open the app and the app tries to connect to the BMS. A metal enclosure will shorten the distance to connect significantly. The battery will work even w/o Bluetooth.

[TheCartBoy]

Originally Posted by TobiasFunke

Which means I need to pull this battery apart?

Here is what it is: https://www.lossigy.com/Products_details/15.html

Really depends on your risk tolerance and what you want to do. A battery with a suspect BMS, I wouldn't put in anyone else's cart. If its just me, well I may do it if I take other precautions like an external fuse close to the battery stud to serve as short and over current protection. Would also make sure my charger will shut off at the right voltage point and not be capable of pushing too much current. And would be mindful to never charger below freezing temps.

But I have repaired some batteries already using JK BMS, so I would probably replace the BMS eventually, then I could have the SOC and cell monitoring and fault information.

[TheCartBoy]

Looks like an ABS case, so Bluetooth should get through. It also says completely sealed, so you might have to cut it open, at which point how will you put it back together to keep moisture out? New enclosure? 6 tubes of caulk?

[jasonojordan]

So sounds like it uses the smartbms app. My guess is its using possibly a Daly bms.

I have had issues in the past where the bluetooth goes to sleep and the app wont see it unless it has a load on it or is being charged.


I would try checking for a bluetooth ID while also either discharging or charging the battery.