Back to track, complete brompton maintenance

[cwah]

Hello all,

I finally finished moving to France. It was a hell of a journey. And shipping 2 bromptons to France wasn't easy at all.

Look at how I've managed to put everything inside massive cardboard:

Unfortunately, when shipping with parcelforce, the cardboard looked like nothing on arrival:

Hopefully, I didn't have too much damage.

I did a sanity check on my battery pack, and the box looked bent on top:

 

[cwah]

There wasn't any voltage from the output of the lead. I decided to dismount my pack to see what happened:

It seems that one of the lead has been disconnected. I think I have to resolder it back.


But I've also noticed this:

One of the cells seems to be damaged and expanded a lot!

Look how it pushed the other cell:

 

[cwah]

Now I need to replace this cell, but I've never done that before, and I was wondering what was the plastic thing around the cell lead? How do I desolder a cell?

That is really annoying, I was thinking that with Lifepo4 I wouldn't have any issue, but I still do have problems.

I now need to replace cell and I don't know where to source them. I think I'll try on endless-sphere second hand cells.

I'm going to buy butane gaz soldering so I will have enough heat to solder these cells:
Dremel 2000 6 Versatip Variable Temp GAS Soldering Iron | eBay

 

[Scimitar]

Oh, pretty bad luck with the battery. Only goes to show, you have to treat shippers as you would gorillas and pack accordingly. Unfortunately, you can't shoot them.

 

[Deleted member 4366]

Sorry to here about that.

What Voltage is it, and are they A123 cells from Victpower?
I'm not sure what plastic thing you're talking about, but the cells have two metal tabs that poke through a a sort of printed circuit board to which they're soldered. The printed circuit board is just a bit of fibreglass with slots for the tabs and pads for the balance wires. If you can, melt all the solder on one tab at a time, and tilt the cell to slide out the tab. Once the tabs are out, you can clear the slots of solder by re-melting the solder and blowing really hard on it to blow it through the slots.

If you can't get a new cell, you can wire it out, and run at 3.3v less. You still need to get rid of the puffed cell, but then you can join the two tabs with thick wire and move the balance wire to the next cell. Many chargers are adjustable. There's a potentiometer inside, which adjusts the voltage, so that you can reduce it by 3.6v.

As an example, a 16S 48v LiFePO4 pack has 16 cells at 3.65v fully charged, so the charger would be set to 58.4v. Take one cell out so that you have 15S: The new charging voltage will be 54.7v, so you loose 6% of your battery.

 

[jerrysimon]

Nice to see you posting again cwah. Glad you have settled in France. Your posts always make me sit up and take notice and this one is no exception. Sorry about the damage I think it was lucky that there was no resulting fire though!

If I recall you purchased your battery pack form Ping ?

If so he will send you a new cell. I am pretty sure you will have to match up the cell exactly.

Regards

Jerry

 

[cwah]

Hehe, thanks all. I'm happy to be back, I hope I'll have more time. Took so holidays for now so I hope I'll have time to fix my 2 bromptons

Scmitar, next time I think I'll have to put everything inside woodboard rather than cardboard lol.

I purchased the battery for Victpower, so warranty is non existent with them. I'll try to buy new cells rather than have less voltage

I'm in contact with OSN Power, apparently it's the only good A123 seller out there. They sell good level cells and also sell kits. I'm thinking of desoldering everything and replace the whole pack into a 20s kit like this:
Free Shipping Professional Assemby Kit for A123 20Ah 36V Battery Pack with Free Screw, Terminal and Connector-in Connectors from Electrical Equipment & Supplies on Aliexpress.com

So it should be easier in the future to repair the pack... because now it's a pain with lead that disconnects.


I'd like to test each cell capacity but I've sold all my hyperion charger... ahah.

Do you know how I can do a lightbulb test with a voltmeter and ampmeter? How do I make sure the amperage isn't too high?

 

[Deleted member 4366]

Best not to do a load test on the individual cells unless you have a proper charger that can do it because you could drain the cells too far to damage them.

You don't need to unsolder everything. Just unsolder the balance wires and BMS. Then add your extra cells as a short extension, and then solder on a 20S BMS with its balance leads.

I don't understand hpw that assembly kit works. Are you sure it's not for cylindrical cells?

 

[cwah]

The kit is made for A123 20AH cells:

It's purely mechanical, nothing to solder. So it's a breeze to replace damaged cell. I expect that to keep happening later lol


I don't have any balance charger anymore and sold them all. But most charger are very bad at discharging. Wondering if there are any good out here?

 

[KirstinS]

I think the 30quid IMAX b6 lipro charger does discharging ok

And it can charge at 5a which does a pretty fast job on a 10ah pack

It can only take up to 6s balance charging though

I'm sure there are other more expensive chargers available that are better. Reviews seem good on the IMAX though

I have not used the discharge function - only balance and bulk charge

 

[cwah]

Thanks Kristin. I've been looking around, and having cycled cells before with my Hyperion. I can tell you it's a hell of a pain to discharge them at low power. It needed 3 days to cycles them and that made me crazy.

I now think to get the Icharger 1010B. It accepts up to 10s battery (so scalable for future) and also accept an external discharger up to 280W so it should be much faster for me to cycle the cells in the future.

 

[cwah]

While I'm waiting for my 1010B charger to arrive, and my butane solder kit to arrive, I'm going to clean the brompton

Here are the tools I have to do a proper maintenance:

I'm going to start with the rear part of my bike:

As you can see, a bit of paint has been removed from the area with the eazy wheels. I think it's also a bit bent with my bike weighting 30 kg But not much I can do I suppose.

I'm going to repaint it buy this rust paint for easyness:
http://www.amazon.co.uk/Hammerite-5092966-750ml-Direct-Smooth/dp/B004R23DE2/ref=sr_1_2?ie=UTF8&qid=1373817405&sr=8-2&keywords=hammerite+black

And use WD-40 to clean the chain. Not sure it's going to be enough. Looks tough to remove.

 

[jerrysimon]

Buy a new chain its not worth the hassle cleaning the old one though you have probably spent the cost of a new chain in cleaning stuff already . The only problem is if the chain is badly worn then you mind find the rear sprocket and main crank teeth are also worn and will need replacing if you fit a new chain.

The frame part linking the two chain stays looks badly corroded and whilst I would recommend that needs a good rubbing down and repainting it depends how much metal is left

The frame part holding the eazy wheel has corroded because it has bent and the paint cracked. Again if you bend it back it may break. I tend to use hammerite paint.

The alternative is to buy a new back frame which is quite expensive and not that easy to remove and refit.


Regards

Jerry

 

[cwah]

hmm.. looks annoying. For sure I'm not going to change the rear frame lol

Do I need to buy a new chain? I don't pedal much anyway I only do it when I have no choice (battery down or cops in the way). And this rusty chain keeps thieves away lol

To repaint, do I have to remove the current paint first? Do I need to use something like heat gun to remove the current paint and repaint it after?

 

[cwah]

Pictures of the rear crank and sprocket. Do they need changing?

 

[jerrysimon]

Hard to tell really. They could certainly do with cleaning up and lubricating though!

You will soon know if they are worn however as when you put on a new chain they will jump when the new chain goes over them. I guess you clean up the old chain and that way you know it would continue to work.

For sure the longer you leave the chain on the more likely it will damage/wear the rear cogs and main crank teeth. Rear cogs are quite cheap but the main Brompton crank is around £50. I change my chain about every 1000-1500 miles and even then I have had to change the rear sprocket some times as once the chain is stretched it wears the teeth on the small back sprocket very quickly. If you have used that chain for more than 2000-3000 miles I suspect your most used rear sprocket will be worn and like I said possibly your main crank teeth too.

Re rust on the frame as long as you clean off all the lose rust then you can paint over the rust to a certain degree with a couple of coats of Hammerite. Not ideal, but will prolong things a little longer and slow down the frame failure. On the older Brompton frames its common for that little cross piece to fail through rust as the water never drained out properly.

Regards

Jerry

 

[cwah]

Will do Jerry. Looks like you've been through it many many times

I've always found it very difficult to clean rust, it tends to stay and never leave away....

I am only using soap for now but I was wondering if there are any other product I can use? Something like the rust removal liquid I sometime see would that work?

Damn that's a lot of work... and I haven't shown you the front part and the wiring

 

[jerrysimon]

Just spray it with your WD40 then use a small wire brush to clean it up.

Afterwards just spray it with GT85 or some other type of spray lubricant. WD40 is not really a lubricant though it will lubricate it for a bit. WD 40 is really to clean off the muck and grease and is a water disperser.

Rust will keep appearing on the chain/sprockets usually when it gets wet and washes off whatever lubricant is on there. So you need to lubricate it every couple of weeks in the wet weather until it gets real messy again when you then have to clean it. I tend to spray WD 40 on mine and wipe it off with a cloth which gets it nice and clean and then just smear it with a little car grease or three in one oil. Others swear by this which I am going to try next. Much better than paying a fortune for all the different types of bike wet and dry lubes.

Need to put a rag behind so it does not go all over the tyres/frame.

Regards

Jerry

 

[Scimitar]

I am only using soap for now but I was wondering if there are any other product I can use? Something like the rust removal liquid I sometime see would that work?

30% phosphoric acid solution is all you need. Brush it on, let it sit for a day and wash it off. That's all that's in most of the rust cures sold for inflated prices.
However, if you don't fancy getting involved with mixing chemicals, just use some Jenolite or Kurust - same stuff, much more expensive.

 

[cwah]

Thanks Jerry. I use wd40 for most or my cleaning but on rust it doesn't seem to work too well.

I was thinking to lubricate with my teflon spray, is it not good? I'm hoping not to have to buy too many new spray lol

Will definitely have to put something to protect others area of the bike when cleaning.


Dave you phosphoric acid solution seems interesting but where do I buy the solution and how do I make it?