48v 10aH LifeP04 Battery Repair

[bedmountain]

Hi everyone.

Last week I attempted to repair a loose charging port on my 48v 10aH LifeP04 Golden Motor battery.
As I opened the top of the case I think the nut at the back of the charging port must have slipped down and touched something it shouldn't. There was a bang and a flash and now the 2 leads to the port have been blown off and are blackened.
I have tried in vain for the last week to find somewhere that is willing to try and check/repair the battery and to be honest I'm a little scared to poke around with it now.
I live in the UK (Cheltenham, Gloucestershire). Does anyone know of anywhere that might be willing to take a look at it for me? At £350 I really can't afford to buy another one and so this may be the end of the road for my electric bike experiment (only 400 miles covered )
I have tried a couple of electric bike shops and even some specialist battery places but nobody is willing to take a look....

Any help/advice would be much appreciated!

 

[d8veh]

I'll fix it for you if you can send it to me. I'm in Telford. No cost for the work. You're not really supposed to send batteries by post, but they don't check. Collect Plus is cheap and reliable. You do it all on line and then take the package to a local corner shop for collection. Cost about £7 each way. Send me a PM if you want to go ahead.

 

[dnmun]

or you could repair it yourself. it would be an opportunity to learn how to maintain your bike yourself which is really essential.

if you don't know how to solder or repair stuff then you can learn by doing it. never too late to start.

when i ship batteries through the post i always put a big label on the outside that says "heavy, power transformer" so they don't throw it.

 

[bedmountain]

Thanks dnmun

I'm not too bad with a soldering iron and am confident having a go at most repairs but after the bang and flash that blew the leads of this battery I'm reluctant to start poking tools into something I have very little knowledge of. The learning curve is a little too steep and painful on this one for my liking.

 

[dnmun]

if you post up pictures of your battery everybody will offer opinions and some help in you figuring out what you are looking at and how to fix it.

if you gonna use an ebike as transportation, you should develop enuff skills and familiarity with the components that you can fix it yourself, even on the side of the road.

 

[Racer_X]

d8veh, really generous of you donating your time like that.
anyone else in my town would charge an arm and a leg.

 

[brumbrum]

I would definitely take up the offer of d8veh. He is a very trust-able and active UK member on here and on the UK forum Pedelecs UK forum. He will be your saviour in this problem which i have observed on the GM forum from your post on there.

Andrew

 

[mlt34]

That's a surprisingly common problem to have. I saw it all the time when I worked in an ebike shop. That nut works itself off from vibrations and shorts the charge leads. The solution is good quality hot glue on the nut combined with heat shrink on the tabs, but not every battery manufacturer does it.

 

[d8veh]

When I repaired it, I did it myself and vaporized the terminal on the connector. Luckily I had a spare one. Before attempting it again, I put an additional Deans connector on the wires so that I could isolate it to put the nut on. As far as I know OP is happily enjoying his battery again now.

 

[bedmountain]

I am Dave - and very much appreciate your work. I've made quite a few mods to the bike since and am getting better with the soldering iron each time! Still too scared to mess with the battery though as I just don't know enough not to fry my fingers. Would love to break down a lifep04 pack so I could remount it within my MTB frame. Am currently taking the internal controller out of my MP3 and fitting an external one.
Thanks again Dave...

 

[mlt34]

Yea I did it myself a couple times. That's a great idea about adding the inline connector. I would just use needle nose pliers and play a higher stakes version of Operation.

 

[Ussyamoto]

I am Dave - and very much appreciate your work. I've made quite a few mods to the bike since and am getting better with the soldering iron each time! Still too scared to mess with the battery though as I just don't know enough not to fry my fingers. Would love to break down a lifep04 pack so I could remount it within my MTB frame. Am currently taking the internal controller out of my MP3 and fitting an external one.
Thanks again Dave...

Your fingers are safe, you can touch the terminals with your bare hands and not get a shock, as long as they're dry. I started with my MP3 without knowing anything and now I have and external kelly controller and have taken the GM lifepo4 pack apart and remounted the cells on my frame. It was easier and safer that I initially thought. Just make sure to tape off your battery terminals while working on them and get some anderson connectors to join everything together or you'll see more sparks. I've sparked and melted a few terminals but these GM cells are tough and handled it well and my fingers are still good to go; these are not Lipos. Only time I've had a serious issue is when I had a dead short on the battery, story here. http://endless-sphere.com/forums/viewtopic.php?f=3&t=63023 Even then no explosions, the cells only got hot. So if you have any skill what so ever with DIY, don't be afraid and just go for it. Replacement cells are relatively cheap anyways if worse comes to worse, http://www.batteryspace.com/lifepo4...gerate32whwith6mscrewterminal-unapproved.aspx. Don't buy replacement parts from GM too, way over priced IMO... you can get better for cheaper somewhere else.

BTW a few tips for when you rewire your MP3 to external controller. Throttle wires are Green/throttle signal, White/5v in, and black/ground. I havn't messed with the orange or brown wires yet but 1 is for the LEDs and the other is for the light switch. Brake wires are blue/brake and black/ground, there is also a red wire but I'm not sure what that's for either. Weird thing is the mp3 brake connector only has 2 pins but has 3 wires. There are plenty of guides to figure out phase/hall sensor configurations. One last thing, while testing your controller, wire in a fuse of some sort or you might get magic smoke. I fried my first replacement controller cause I shorted it through ground and that could have been avoided with a simple 20A automotive fuse. I now do not do any testing without it. Remove the fuse when you're done with testing with everything workings or you'll just blow the fuse the first time you put any loan on the motor.

That's all, sorry for the long message xD

 

[amberwolf]

The solution is good quality hot glue on the nut combined with heat shrink on the tabs, but not every battery manufacturer does it.

Loctite or similar would be a better solution than hot glue....

 

[mlt34]

The solution is good quality hot glue on the nut combined with heat shrink on the tabs, but not every battery manufacturer does it.

Loctite or similar would be a better solution than hot glue....

That's interesting, loctite probably would be a good solution. I wonder why many manufactures use hot glue and not loctite. I think it could have something to do with serviceability. Even blue loctite would be tough to remove. And when you're working with plastic parts/metal hardware, too much force could probably lead to cracking something. I'm not sure, just a thought. Maybe I'll use loctite from now though instead of hot glue, the installation would certainly be simpler. No more napalm fingers :lol:

 

[amberwolf]

Hotglue may also be cheaper, and it's easier to see that it got applied, if any actual QC is done :lol:

I doubt serviceability enters into the equation, as so few places honor warranties (if they even give them in teh firs tplace!) that it doesn't seem to apply.

 

[fourbanger]

I believe hotglue would be much faster on the assembly line: Fasten all the nuts; done. Grab gluer; glue all fastenings; done. NEXT!

I really like this thread. People helping people solve their problems together, learning from advice and experience that nothing's really *that* hard.

Cool.