Help! Looking for battery control board advice for Oxygen eMate 13Ah MTB 2015

[minimaltoo]

Hi all,

I picked up a great value eMate a few weeks ago as an unwanted PX at a local bike shop - they said the battery had been fixed as it was dead at trade-in. It's cut out on me 3 times in 335 miles, each time in heavy rain, and it always came back after a minute or two off, until this morning.

Went round all the connectors with WD40 and a cloth, but nothing got it working again. Spent 30 minutes trying to remove the battery, and when I unscrewed the two halves found that the power feed into the controller had been superglued in place...

Going over things with a multimeter the battery pack does have 30+ volts in it, but looking more closely at the board (BMS ?) it seems like a red sense wire has come off (yellow circle) and I am wondering if it came from the empty solder pad in the purple circle:



I think the power switch board uses the disconnected red wire, but I'm a bit puzzled as there's still a voltage at the exit pins into the controller box under the battery but no amount of button pressing gets the LCD to come on.

Does that floating wire do anything more than light up the LEDs on the battery pack ? If so, then that's never worked the entire time I've had the bike (those lights have always been off).

Any and all advice most welcome, as this bike is too much fun to leave in the garage, but I'm not sure where to start digging next.

 

[Nealh]

Yes it needs soldering back in place other wise is will cause a short if it contacts something else, that pad is marked B+.

I have my pair of old cases so will see if the BMS is still with them or not to check on the wire location as the battery is the same Daskit one used on the Oxydrive kits.

 

[vfr400]

The red wire should be soldered to that pad. I'm not sure what it does. it might be to power the USB and indicator lights, or maybe the whole board.. You should charge the battery right up to do any testing. It should be over 40v.

When you get it to 40v+ and it still doesn't work, switch it on and measure the voltage coming in to the controller board in the receiver compartment. If you have 40+ volts there, check the voltage on the red wire on the connector that goes to the LCD.

 

[minimaltoo]

Thanks both - my apologies for the delay in replying but I've got stuck on mechanical issues trying to get to the controller. The battery connector is glued most strongly on the left, and in trying to pull it off (before I knew it was glued !) you can see that I broke off the left screw lug.

Using a thin metal shim I have tried to lever the plug out across the flat front you can see in the image, but that only seems to have loosened the right hand side. Removing the bottle mounting screws doesn't release the full mounting bracket as it feels like there's another attachment point under the controller box.

Unscrewing the controller cover from the bottom (down tube side) also doesn't work, as whilst 3 screws came out easily, the fourth is too tight to get purchase on, as it's so close to the down tube I can't get a straight access with the screwdriver.

My soldering iron doesn't appear to be beefy enough to de solder the battery power lines cleanly from the plug, so I think I'm down to destructive options such as chopping off pins with wire cutters, but that just feels like a bad idea on top of a bad idea...

Are there any more mounting screws which can only be accessed from within the controller box, or do I just need to remove the two screws which are obscured by the connector pin & power cable (blue arrows in the image) ? If it's just those two then I may just end up butchering the connector, but if I need to get inside the controller box as well then I'm still going to be stuck, I think.

 

[Nealh]

Looks like the mating connection is fused together, either the pins have been fused by possible cross polarity or corrosion may have stuck them together.
The battery connection with the v+/v- attached should disconnect and is a two piece male/female connection.
You may be able to remove the controller from underneath, on the heatsink base there are four small screws that are accessible. I was able to do this but depends on the down tube size.

 

[vfr400]

Those two screws have nuts on the back, so you have to remove the whole receiver from your bike to undo them. all they do is hold the controller to the aluminium mounting strip. It's possible that one of them has been lengthened and another rivnut added to the frame to use it as a third fixing. There's not much room inside the box to drill another hole for a mounting screw - maybe just enough room at the front. Normally, it's only the two on the aluminium strip that hold it to the frame.

I think you're going to have to remove the 4th screw to see what's up. It's only in plastic, so shouldn't be very tight. Can't you get it out with one of those small flat electrical screwdrivers?

 

[vfr400]

Those connectors often give trouble. If the worst comes to the worst, you can chuck them and use any connector, like a Deans or XT60, then seal the opening in the controller box. Leave about 200mm of wire, which will tuck into the battery when you clip it on. No water will go in through the hole in the battery because it faces downwards.

 

[Nealh]

If MM can access the 4 screws from underneath then he can remove the controller to gain access to the pair of screws arrowed.

The set up is DASKIT stuff and also as mentioned the same as the Oxydrive kits now no longer available.
My battery /controller connection never gave me any issue and I still have the empty controller base and two battery cases, In the future I plan one day to utilise them again as 48v as I can just squeeze in 52cells with a little adjustment internally with a Dremel cutter and add a new bms. Controller wise it will be an external 9 fet one.

The only faults I found were the bms gave me issues after about 3.5k miles and the 22F & 26F Samsung cells were a bit crappy after 18 months use, other wise the kit was very good and the CST Bafang hub is still going strong and in regular use.

 

[minimaltoo]

Thanks again all

The down tube is a rounded square-ish shape, and the screw that's being awkward is the only one that's corroded (of course !) and is also only visible due to the rounded edge of the tube, so the screwdriver is going in at a 45 degree angle and so it's proving tricky to get purchase on it.

Knowing that it's the best way in is exceedingly helpful, so I shall attack just that portion with more effort - I gave it a WD40 soak this morning so maybe this evening it'll be a little more co-operative.

I'd been hopeful that I could just remove the battery, check for proper connections/wiggle reluctant cables and connecters, give the battery a charge whilst off the bike and be back on the road again.

I'm also comfortable with putting the controller into a different box and get a custom cable up to a rear pannier rack mounted battery if the current one has been shorted/broken/the source of my problems, but wanted to leave that as a last resort due to the length of time that'll take.

Cheers everyone !

 

[minimaltoo]

I'm pleased to say that the WD40 did the trick, and after a very slow and careful go with a series of screwdrivers, I finally got the final screw out, and it looks like the cause of the failure is that the black power lead came off the connector:



The downside is that before I got this far, the battery pack fell off the bike and ripped the wires from the charging socket and BMS board:



I can see where the negative has been ripped from the underside of the BMS as the lead to the cells is still in place, and both red and black from the button have obvious targets, but I'm not sure how the fuse is connected as I'd not seen that until it was ripped out of the insulation wrapping...

Does it fit on the stub coming from the cells (above left image) ? And did I read it correctly that it should be a 20A fuse ?

Oh, and if anyone knows the correct RS/Farnell part for a new DC jack socket then that would be awesome. I should add that I'm equally happy to buy parts from forum members if it helps supports them/this forum !

 

[Nealh]

The fuse is connected to the v+/red on the discharge side , inline on the v+ from cell group #10 and the battery discharge connector.

 

[vfr400]

Take your pick. It might be an idea to get a plug as well as a socket in case the middle pin doesn't fit:

5.5mm dc jack socket for sale | eBay

Find great deals on eBay for 5.5mm dc jack socket. Shop with confidence.

www.ebay.co.uk

 

[Nealh]

Hi all,

I picked up a great value eMate a few weeks ago as an unwanted PX at a local bike shop - they said the battery had been fixed as it was dead at trade-in. It's cut out on me 3 times in 335 miles, each time in heavy rain, and it always came back after a minute or two off, until this morning.

Went round all the connectors with WD40 and a cloth, but nothing got it working again. Spent 30 minutes trying to remove the battery, and when I unscrewed the two halves found that the power feed into the controller had been superglued in place...

Going over things with a multimeter the battery pack does have 30+ volts in it, but looking more closely at the board (BMS ?) it seems like a red sense wire has come off (yellow circle) and I am wondering if it came from the empty solder pad in the purple circle:

View attachment 32456

I think the power switch board uses the disconnected red wire, but I'm a bit puzzled as there's still a voltage at the exit pins into the controller box under the battery but no amount of button pressing gets the LCD to come on.

Does that floating wire do anything more than light up the LEDs on the battery pack ? If so, then that's never worked the entire time I've had the bike (those lights have always been off).

Any and all advice most welcome, as this bike is too much fun to leave in the garage, but I'm not sure where to start digging next.

For you my old oxydrive bms pic

 

[Nealh]

I'm pleased to say that the WD40 did the trick, and after a very slow and careful go with a series of screwdrivers, I finally got the final screw out, and it looks like the cause of the failure is that the black power lead came off the connector:

View attachment 32482

The downside is that before I got this far, the battery pack fell off the bike and ripped the wires from the charging socket and BMS board:

View attachment 32483

I can see where the negative has been ripped from the underside of the BMS as the lead to the cells is still in place, and both red and black from the button have obvious targets, but I'm not sure how the fuse is connected as I'd not seen that until it was ripped out of the insulation wrapping...

Does it fit on the stub coming from the cells (above left image) ? And did I read it correctly that it should be a 20A fuse ?

Oh, and if anyone knows the correct RS/Farnell part for a new DC jack socket then that would be awesome. I should add that I'm equally happy to buy parts from forum members if it helps supports them/this forum !

Best fuse pic I can find, if you need other pic Q's just ask away I might be able to find more, the fuse is also T'd off to the charge inlet and as previously mentioned the v+ with white sheath is to the discharge connector.

 

[vfr400]

There should be two black wires on that output pad, one for the charger and one for the main power. It looks like you changed something there.

 

[Nealh]

The main discharge and charge points utilise pads on the reverse of the board.


The pads we can see on top in the pic on post#13 are a 5v power supply for the switch/leds and usb output.

 

[vfr400]

That's right. i was thinking in two dimensions instead of three.

 

[minimaltoo]

Thanks a bunch for the images, and yes, I am missing a black wire on the base of the BMS board due to the battery falling off the bike and yanking it off the board for me...

I've found a likely socket on eBay and that's on order, along with a motorbike in-line mini-blade fuse holder & 20A fuse as the battery/controller connector is so totally broken I'll need to redo the wiring there.

Having prized the original battery connector out of it's 'glued in' position it looks like the ground wire may have been working loose for quite some time as it seems like the plastic has been burnt by an arcing connection - it certainly has a strong burnt plastic aroma to it, and the pin on the controller side is almost unrecognisable:



I've also got some 5mm rubber sheet on order so I can plug the connector hole into the controller and just punch the two power wires through it to the bullet connectors, and then put spare wire into the battery case so there's just enough room to demount it if required.

 

[vfr400]

Those connectors were always troublesome for some reason. Somebody made a small batch of much more robust replacement connectors for Oxydrive kits, but they soon ran out. Those batteries are still used on various Das Kit bikes. I guess that they must have changed something by now, but one weird thing, there's a guy in Poland that sold the same Das Kit at the same time, but he didn't get the same problem that plagued nearly every Oxydrive one.

 

[minimaltoo]

It’s been a while, but that was mainly waiting for eBay parts and 1.5mm2 wire as everything I had on hand was smaller than the original diameter.

The good news is that I did 25 miles on it today, and it was down to the last bar on the meter when I got home again.

The bad news is that the charger LED stays green, and never goes red

I took the Cell 10 (+ve) connector into a 20A fuse, and then on to the centre pin of the DC socket, and down into the controller power input. I took the negative lead from the bottom of the BMS to one of the ground pins on the DC socket, and the other ground pin went down into the controller power ground.

Before things broke, the switch on the side of the battery never worked - that was due to the missing red wire back at the start of the thread. I’ve fixed that and the battery switch does work properly now. I’ve tried charging with the switch on and off, and it makes no difference to the charger LED.

With the charger disconnected, the display voltage says 35.3v and if I leave the display on when I connect the charger, the display does show that the voltage rises to 42v, so it does seem like it ought to be charging.

I didn’t notice any loose sense wires, but the battery pack is firmly glued into one half of the shell and the wiring sucks and dives a lot through many layers of tape, so I might have missed something.

Thanks for the advice so far - I’m hoping there’s something equally easy that can be done to get it charging again !