Moscow Plus Battery BMS Dead

blueskyca

Member
Region
USA
City
SoCal
In what appears to be a somewhat common occurrence, I went for a ride in a light California drizzle and hit a few puddles but nothing extreme. When I returned I put the battery on the charger and saw it was charging normally. When I returned a few hours later the charger showed green but I could not get any LEDs to respond on the battery.

I took the top battery cap off and found maybe a couple drops of water in the BMS compartment so I blew it out with compressed air and gently warmed the parts with a heat gun. The BMS and battery power indicator board look pristine, unlike others who had visible corrosion from water intrusion, but still no power or charging. I tried several BMS reset suggestions that didn't work as well. There is a flashing red light on the BMS PCB.

I probed the individual battery voltages at the14 pin connector (disconnected) and found all cells are sitting around 4V each. However, when I connect the BMS, cell 4 voltage (to ground) would spike up to around 16 volts (about normal) then immediately drop down to about 12 volts, which is what the cell 3 connection is measuring. This repeats about every 2 seconds. It looks like something is loading down the cell 4 connection and the BMS refuses to charge or discharge. I probed a few components on the boards and found nothing obvious.

It doesn't appear there are any sources for the DeHawk BMS. At the moment, I'm thinking about replacing the BMS with a non-DeHawk BMS with a power switch feature. I should be able to retain the LED battery power display indicator as well as the USB port. I'll also need to replace the momentary push button switch with a latching type and wire it to the new BMS.

Any suggestions before I commit myself to a few hours of work?
 

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Yes, head over to endless_sphere.com and poke someone like Amberwolf. A better forum for battery rebuild threads.

Hee's a good thread.
 
In what appears to be a somewhat common occurrence, I went for a ride in a light California drizzle and hit a few puddles but nothing extreme. When I returned I put the battery on the charger and saw it was charging normally. When I returned a few hours later the charger showed green but I could not get any LEDs to respond on the battery.

I took the top battery cap off and found maybe a couple drops of water in the BMS compartment so I blew it out with compressed air and gently warmed the parts with a heat gun. The BMS and battery power indicator board look pristine, unlike others who had visible corrosion from water intrusion, but still no power or charging. I tried several BMS reset suggestions that didn't work as well. There is a flashing red light on the BMS PCB.

I probed the individual battery voltages at the14 pin connector (disconnected) and found all cells are sitting around 4V each. However, when I connect the BMS, cell 4 voltage (to ground) would spike up to around 16 volts (about normal) then immediately drop down to about 12 volts, which is what the cell 3 connection is measuring. This repeats about every 2 seconds. It looks like something is loading down the cell 4 connection and the BMS refuses to charge or discharge. I probed a few components on the boards and found nothing obvious.

It doesn't appear there are any sources for the DeHawk BMS. At the moment, I'm thinking about replacing the BMS with a non-DeHawk BMS with a power switch feature. I should be able to retain the LED battery power display indicator as well as the USB port. I'll also need to replace the momentary push button switch with a latching type and wire it to the new BMS.

Any suggestions before I commit myself to a few hours of work?
If you do go ahead with this, would you be able to post a link to the BMS you choose and the latching switch you choose?
 
I'll keep you posted. This is the BMS I ordered - unfortunately I had to resort to AliExpress so it won't be here until February.
 

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I received that same Be_Much_Safer BMS yesterday. I have never used these guys (Be_Much_safer? good grief) before, but their unit seemed to be one of the smaller circuit boards, and I need it small to fit in my battery case. I placed the order on Dec 22, and it arrived Jan 10. That's 21 days or 3 weeks.
.
Should have it wired in tomorrow. Am putting new Samsung cells in a old style Dolphin Case,

P1111367.JPG
 
I received that same Be_Much_Safer BMS yesterday. I have never used these guys (Be_Much_safer? good grief) before, but their unit seemed to be one of the smaller circuit boards, and I need it small to fit in my battery case. I placed the order on Dec 22, and it arrived Jan 10. That's 21 days or 3 weeks.
.
Should have it wired in tomorrow. Am putting new Samsung cells in a old style Dolphin Case,

View attachment 144471
Yeah there weren't a lot of options for a 13S BMS > 30A with disable feature and balancing. At least they posted lots of specs on the BMS and look pretty legit. Let us know how it works out. And this should just barely fit into the Reention battery case.
 
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Pilot error. They sell this with/without the switch for the same price, and I didn't look at the option., so I ordered one without the switch. I had to re-order it. They offered to swap if I sent it back, but not for a $24 part. Would have bought the annpower model, but it's 6mm wider, and won't fit.
.
It did power up. Charges too,
 
Pilot error. They sell this with/without the switch for the same price, and I didn't look at the option., so I ordered one without the switch. I had to re-order it. They offered to swap if I sent it back, but not for a $24 part. Would have bought the annpower model, but it's 6mm wider, and won't fit.
.
It did power up. Charges too,
I'll bet there's a simple PCB mod to get the switch working on your no-switch bms. They're likely the same board.
 
Have you guys ever used this stuff?

20230113_111212.jpg

I've got a Reention Dorado battery that may have the same BMS?

I'm thinking of coating it.
 
ACF 50 and Boeshield are coatings used on avionics. But I just work over every battery case seam with a high quality black RTV and coat the external connectors.

Maybe I'll do both.
I use dielectric grease on my external connectors.
 
dielectric grease
Messy stuff and so old school when superior products have been around for decades. In my experience... I figure if it's good enough for avionics my eBike will benefit.

  • ACF-50 kills any corrosion currently in progress with just one application.
  • ACF-50 is non-flammable, non-carcinogenic, and virtually non-toxic.
  • ACF-50 can be safely applied to electronics such as radios, timers, test equipment, antenna connections, computers, etc.
  • ACF-50 can be safely applied to electrical components such as alternators, starters, magnetos, generators, distributors, carburetors, wiring, switches, rheostats, compressors, battery terminals, light bulb sockets, electrical connectors, circuit breakers, ignition systems, wire harnesses, etc.
  • ACF-50 provides excellent low-shear lubrication to moving parts and cables.
 
That's even more money.
And neither are available at my local Canadian Tire or Home Hardware.


Screenshot_20230113-144318_eBay.jpgScreenshot_20230113-144555_Amazon Shopping.jpg


What about this from Home Hardware??


Screenshot_20230113-150443_DuckDuckGo.jpgScreenshot_20230113-150532_DuckDuckGo.jpg

And they use isobutane and propane as a propellant, so it will make an awesome blowtorch. Lol
 
There is also this option,..

Screenshot_20230114-055653_DuckDuckGo.jpgScreenshot_20230114-055903_DuckDuckGo.jpg

They are both synthetic and safe for plastic and rubber and don't conduct electricity, but the KP53 is thinner, penetrates better and probably isn't as messy?

I'll use it to replace my WD-40.
 
The new BMS arrived ahead of schedule so I wired it up and jammed it in. And I mean jammed. It's uncomfortably tight but I think it will be OK. The battery charge level indicator lights work but I've pretty much given up on getting the USB port back in action. I'm still waiting for my latching push button micro switches to arrive but the switch function on the BMS works well. It took a while to find a BMS with the on/off switch function so I'm not sure I could find another BMS that is smaller. But I would try if I was to do it over...
 

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In what appears to be a somewhat common occurrence, I went for a ride in a light California drizzle and hit a few puddles but nothing extreme. When I returned I put the battery on the charger and saw it was charging normally. When I returned a few hours later the charger showed green but I could not get any LEDs to respond on the battery.

I took the top battery cap off and found maybe a couple drops of water in the BMS compartment so I blew it out with compressed air and gently warmed the parts with a heat gun. The BMS and battery power indicator board look pristine, unlike others who had visible corrosion from water intrusion, but still no power or charging. I tried several BMS reset suggestions that didn't work as well. There is a flashing red light on the BMS PCB.

I probed the individual battery voltages at the14 pin connector (disconnected) and found all cells are sitting around 4V each. However, when I connect the BMS, cell 4 voltage (to ground) would spike up to around 16 volts (about normal) then immediately drop down to about 12 volts, which is what the cell 3 connection is measuring. This repeats about every 2 seconds. It looks like something is loading down the cell 4 connection and the BMS refuses to charge or discharge. I probed a few components on the boards and found nothing obvious.

It doesn't appear there are any sources for the DeHawk BMS. At the moment, I'm thinking about replacing the BMS with a non-DeHawk BMS with a power switch feature. I should be able to retain the LED battery power display indicator as well as the USB port. I'll also need to replace the momentary push button switch with a latching type and wire it to the new BMS.

Any suggestions before I commit myself to a few hours of work?
How did you reset the BMS? My charger trip's out every time I plug it into the battery and starts flashing red?
 
How did you reset the BMS? My charger trip's out every time I plug it into the battery and starts flashing red?
I tried several methods involving pressing and holding the battery power button, charging through the discharge port, disconnecting the BMS leads and charging... Nothing worked. This Biktrix video gave me some hope but didn't work in the end.

 
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