New bottle battery under the rain... is dead :(

[cwah]

hello all,

It has been raining a lot today, and as usual I parked my bike outside until I finished work. But when I came back to ride my bike it worked fine for 5mn... then I heard a "bang". Then light off. No more power.

I was wondering what happened... then I turned off the battery, then turn it on again and it was working... but 5 seconds after another "bang" and all stopped.

No more light from the battery plug. The battery I purchased is this one:
https://bmsbattery.com/ebike-battery/685-48v10ah-bottle-09-e-bike-battery-charger-battery.html

I removed the battery to inspect, and I've realised a lot of water leaking out of the battery.

I had to pedal back home


I opened it back home, it was full of water, I dried it up and checked the bms:

Fuse is intact. It was smelling a bit the melted plastic when I opened the box. I think the bms is dead.

What should I do???

 

[D8ve]

Top photo under the PCM
It looks like the Fet has blown.
A close up photo of it and it's neighbour should show I'd number and damage?
Then it's a test with DVM and some soldering to confirm/replace

 

[cwah]

The PCM is glued to the board. So I'd need to remove the glue to tke a picture.

How do I test if a Fet has blown?

have you seen the second picture? It seems that something exploded.

What is a DVM and what a test with DVM? And what do I solder? Thanks you.

 

[Deleted member 4366]

Is it the photo or does the bottom MOSFET have soot all over it? (top picture)

None of these bottle batteries are waterproof enough to be left out in the rain. These ones will let in water where the handle is. You should cover them if you're going to leave them out.

Hopefully, the cell-pack is OK, but you need to check the cell voltages before it's too late.Use a voltmeter with your black probe on the pad marked B- and your red probe on each pin of the two multipin connectors with white wire, i.e positions B1 to B13. That big orange thing with OK written on it is also a fuse. Check that it's still conducting.

 

[cwah]

So I check cells voltage and conductivity check on the big orange thing? What about the Fets? I think it's the picture that looks darker. Do I also do conductivity test on the first and last leg?

 

[Deleted member 4366]

I have exactly the same battery, so I opened it up. It seems that you've blown the two capacitors in the corner. That was why there were two bangs.They're used by the USB, so shouldn't matter too much, but if you had water in your BMS, you might have wiped out anything.. The fact that your bike still worked after the first blew confirms that they're not needed..

 

[Deleted member 4366]

So I check cells voltage and conductivity check on the big orange thing? What about the Fets? I think it's the picture that looks darker. Do I also do conductivity test on the first and last leg?

The FET will only be a problem if it has soot on it. I think it'll be OK now that wev'e identified the source of the two bangs. You still ned to check the cells and that fuse.

 

[cwah]

The fuse is ok as per the picture. I'm going to check cells voltage but I don't see why it would be a problem

 

[cwah]

I tried to turn it on, and I realised the power is getting on... but it is blinking. The blue light is blinking!!

What is going on?

 

[cwah]

It stopped blinking!!!

It happened to my bike a bit before, it was running for 5 seconds then all turned off without bang. What's wrong?

 

[anotherkiwi]

None of these bottle batteries are waterproof enough to be left out in the rain. These ones will let in water where the handle is. You should cover them if you're going to leave them out.

Hope I am on topic: can they be made more water resistant with some well placed silicone?

Cheers
Tony

 

[trex]

no, but a shower cap may.

water can follow so many pathways that it's just impossible to be completely sure. Tiny space through all the connectors, bolts and lock can let water in, even when these are protected with rubber seals. Simplest solution is to put a hat over your battery.

 

[Deleted member 4366]

It's the orange fuse with OK written on it that you need to check. Then check the cell voltages. There's no point in trying to guess what's wrong. Measurements will show you.

 

[KirstinS]

I have the 12.5ah 36v version of this battery from BMS.

I use a 11.1v booster battery and I have noticed that when I finish a ride I turn the LED panel off, then I switch this battery off using the blue button. It then blinks for about 10 seconds before going off.

If I ride without a booster battery it doesnt do this - it just switches off

I have presumed that it is something to do with the BMS detecting a low voltage (in my case it sees 11.1v wehn it should be 36v)

This may lend some weight to some of the cells being 0 or low. Why might this be ? Well water can easily short them out and drain them. A have opened an old style bottle battery where exactly this had happened. Water had damaged the BMS and taken 3 cell series to 0

 

[anotherkiwi]

Putting cheap bicycle cover on shopping list....

Tony

 

[Deleted member 4366]

Mine blinks when on charge and still switched on.

 

[trex]

@cwah
how about bypassing the output FETs for now until you can get a new PCM from China?

 

[Deleted member 4366]

He needs to test it first to find out what's wrong. Maybe nothing - just needs cells to be charged.

 

[jonathan75]

Putting cheap bicycle cover on shopping list....

Tony

Could anybody recommend one of these please? Aren't they a danger in crosswinds? Or in causing onlookers to have accidents due to uncontrollable laughter?

Seriously the thought of designing a rain device just for covering the battery appeals more - it could be a drawstring waterproof cover (like a shower cap but custom made), with the mounting plate sealed up with silicone, and a velcro bottom cover to go over the remaining bits at risk of ingress... but given the battery seems to be vented, could such a design precipitate a heat build-up which might damage the battery, shorten its life, or cause a seriously increased risk of some danger?

 

[flecc]

Seriously the thought of designing a rain device just for covering the battery appeals more - it could be a drawstring waterproof cover (like a shower cap but custom made), with the mounting plate sealed up with silicone, and a velcro bottom cover to go over the remaining bits at risk of ingress... but given the battery seems to be vented, could such a design precipitate a heat build-up which might damage the battery, shorten its life, or cause a seriously increased risk of some danger?

Check this one out with Martin at e-bikeshop Jonathan.

I don't know if it's waterproof, but as Bosch make it, there won't be an overheating issue.
.