Think my charger has failed?

[Synthman]

Yesterday had a bad journey as one of the wires in the battery came loose and I lost power twice. Got home, soldered it back on, and tried to charge it. The red light wouldn't come on.

I got my multimeter out and checked both the charge and load connectors, and got a good reading. I opened the battery up again and checked all the connectors and reassembled. Plugged the charger back in and the red light did indeed come on, but the green light came back on too early. Checked battery voltage again and it was about 39v. I thought the charge connector might be dodgy, as I could hear the charger clicking on and off as the connector was inserted/removed.

I tried connecting the charger first, then plugging it into the mains. The red light came on and I watched it for about 45 minutes. The charger wasn't getting anywhere near as hot as it was usually. I then decided to measure the battery again and the charger output. Battery voltage had barely gone up, and there were basically no volts coming out of the charger, and the polarity kept switching.

The charger is a 1.8A 42V by Sans Electric Co LTD, with an XLR jack. It has done 143 charges. I've got a month's warranty left on the bike, not that it matters as I'm sure they'll find a way of not giving me a replacement. The charger is dangerous as the cover can easily be pulled apart.

I'm really pissed off as I didn't need this trouble or expense right now. I need a quick way of getting a suitable replacement, if anyone knows where to get one or has a spare please let me know. Cheers.

 

[Marky T]

Hi Synthman,
Sorry to hear about that, there's always something to zap your money. Is the bike cutting out now when you ride it? I say this because I had a problem a few weeks ago, it turned out to be one of the battery cells.
Marky T

 

[Synthman]

The cutting out problem has been persistent over the last 6 months, always due to a loose wire somewhere. I put a block of wood in the pack to take up movement of the two battery packs inside, so the problem went away for the last 3 months. This time the weight of the fuse and holder + wires and the state of the roads contributed to the live wire of the load socket nearly coming off completely. It was literally hanging on by a thread! But no the battery has never cut out because it couldn't cope with the load. I'm saving what's left of my battery charge for emergencies only, so I haven't tested it on the bike yet.

 

[Synthman]

My mum said I should have checked the fuse in the charger, so I got the cover off and checked the continuity. Fuse is fine. The output is putting out half a volt, and I'm 100% certain its dead.

I would like a slightly quicker charger, preferably with a fan but I can't find one. Would the Phylion battery mind if the charger has higher amps?

This is identical to the charger I have now. FreeGo 10Ah Electric Bike Battery Charger - Black

This is what I'm thinking of replacing it with. New 36V Lithium battery charger for electric E bikes on eBay (end time 07-Jan-11 20:38:54 GMT)

 

[JuicyBike]

We use compatible chargers....
Juicy Bike Accessories: stylish electric bikes and scooters
But you should get yours replaced under the FGo warranty. Or ask them to fix it within 5 days.... According to their adverts you'll get a new bike if they can't fix it...

 

[Synthman]

Should have made clear that my charger didn't come from them, that was the only identical replacement I could find. I want no further dealings with my ebike supplier.

 

[Synthman]

I bought the Sunlova charger, however their warehouse is shut until after the new year so will probably have to wait at least a week! I was lucky the charger did put something into the battery before it failed completely, and I've got 39.4v left, enough for a few short trips I think.

 

[eddieo]

It really helps to put what bike you have in your signature? As I for one have not got a clue as to what bike you are talking about......

 

[Synthman]

Good point, will add a signature soon. The bike is "Ninja Electric Bike/Scooter" not to be confused with a Kawasaki.

 

[Synthman]

Can you believe my bad luck?

Got the charger today. Plugged it in, green light came on followed by the fan. Plugged it in to the battery, red light comes on. I check it 3 mins later and there's no lights.

I checked the plug fuse, which is the worst I've ever seen. One of the end caps came off but that wasn't the problem. There is still output on the charger, and its getting warm, I'll have to check battery voltage in an hour to see if there's an increase. If there is I can take up the issue with the seller, as no LEDs would be a nuisance.

The worst case scenario is that I take a CBT as soon as possible, and upon completion, go straight to my local scooter shop and buy a Vespa GTS 125 super ie, and post my leaving thread here.

 

[Synthman]

Ok I give up thats it.

 

[NRG]

Ok I give up thats it.

Sorry to hear this Synthman, eletrical problems can be very frustrating to resolve but worth it in the end...although I can fully empathise when it gets too much, sometimes you just have to throw in the towel...

 

[Dynamic Position]

Ok I give up thats it.

Don't give up yet.

The problem is likely to be with the battery along the lines Marky T has suggested? The charger (SMPSU) probably will be looking for an attached battery (load) before it provides significant output so that is why you are getting the low reading. Check connection points are clean. You should open up the battery and check internal connections again because it would appear your battery has an open circuit. Have a look to see if there is a in-line fuse that may have blown by checking the impedance (resistance) of wire connections from battery terminal to where they are connected to Battery Management Circuit Board. If continuity of each wire is confirmed you could visually check BMS Circuit Board.
I think the problem suggested by Marky T is unlikely because the battery is still able to supply power to your bike without problem.

 

[eddieo]

The worst case scenario is that I take a CBT as soon as possible, and upon completion, go straight to my local scooter shop and buy a Vespa GTS 125 super ie, and post my leaving thread here.

Or you could have bought a decent, well reviewed e bike in the first place instead of your ninja wotsit

 

[Synthman]

Don't give up yet.

The problem is likely to be with the battery along the lines Marky T has suggested? The charger (SMPSU) probably will be looking for an attached battery (load) before it provides significant output so that is why you are getting the low reading. Check connection points are clean. You should open up the battery and check internal connections again because it would appear your battery has an open circuit. Have a look to see if there is a in-line fuse that may have blown by checking the impedance (resistance) of wire connections from battery terminal to where they are connected to Battery Management Circuit Board. If continuity of each wire is confirmed you could visually check BMS Circuit Board.
I think the problem suggested by Marky T is unlikely because the battery is still able to supply power to your bike without problem.

I've measured the charger output without a load and it is still 42v (when it was working of course). When the first one was playing up, I measured the output and it had gone up to over 48v just before it died. Second one also nearly hit 49 volts after the lights went out. They're actually sending me a new charger after confirming my battery is indeed 36-37v, but I will be too afraid to try it, as I fear there is a problem with the battery that is causing this.

As for continuity there's no broken connections either to the charge or load ports, and the 5a fuse is intact. How would I go about checking the BMS, what exactly am I looking for?

Or you could have bought a decent, well reviewed e bike in the first place instead of your ninja wotsit

Apart from one issue with the chain slipping (and I hardly pedal ) the bike is not at fault. The dealer is for supplying me with an ancient battery, and also for moderating reviews on their site. I wonder if I should just have done and rip out all the battery internals and contact Li Ping or whoever can supply new cells.

 

[Dynamic Position]

As for continuity there's no broken connections either to the charge or load ports, and the 5a fuse is intact. How would I go about checking the BMS, what exactly am I looking for?

It might be possible to spot a hairline crack or you could look and see if the quality of the solder joints are okay. Running a hot solder iron over a dry joint might just fix the problem (do not do this if components are the extremely small surface mount type)? If it is a component fault then then you probably will need to get a new battery unless you can source a new board or component to fix the problem.

I assume that when you try and charge the battery the ambient temperature is within the range given by the manufacturer?

 

[Synthman]

Each charge has been done at a temperature of 19-21c, don't have any documentation that states the correct temperature.

I'm going to attempt a visual check of the BMS if I can get to it, and every single connection, either way I won't take the risk in wrecking another charger. The only good thing is this XH370-10J seems common and if the BMS is fried, might be able to get another one.

 

[Synthman]

I had some difficulty removing the bottom battery pack, but have finally got to the BMS, looks a bit dusty but there's no sign of anything wrong visually.

Someone prevented me from taking a sledgehammer to the battery casing, which is the equivalent of a short ride through Oxford.

I reckon I can get the entire Ninja into a few plastic bags when I take the panels off and cut the frame to pieces. Might keep the motor and controller, might not either. Might even make my first youtube video of the process.

 

[Synthman]

I reassembled the battery really carefully, and thought I had nothing to lose by testing the new charger. Glad I did as it seems to be charging perfectly now. If nothing goes wrong in the next 2 hours it should be fine. P.S. it seems I was correct about the chargers putting voltage out even if not connected to the battery.

I had a look in the first charger they sent me, the heatsink, capacitors and everything else shifted to one side, either bad manufacturing or damaged in transit.

 

[Synthman]

I'm pleased to announce the charge was a success. Took 15 mins longer than usual which got me worried, however my battery has never been left standing that long after going flat.

I think lessons can be learned from this thread. I think it was just a coincidence that the charger died the same day after resoldering a loose wire, something I've done at least half a dozen times on the battery without trouble. For the replacement charger to die straight away is just bad luck. Very impressed with Sunlova's service, if only my original dealer were half as good as that...