Refurbing bike batteries

Electrically assisted bikes, trikes, etc. that are legal in the UK
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Refurbing bike batteries

Post by simonineaston »

Anyone any experience of refurbishing batteries in use with 'leccy bikes? My own Bosch 36v 2ah battery is coming to the end of its useful life and I imagine that inside, there are the same basic units that everyone else seems to use.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Refurbing bike batteries

Post by simonineaston »

Much to my surprise, I just found this...
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
borisface
Posts: 360
Joined: 19 Feb 2010, 3:48pm

Re: Refurbing bike batteries

Post by borisface »

Sounds easy (as things like that often do on the net) but I suspect that there are all kinds of potential pitfalls not least is the voiding of any warranty, if that matters anymore. Maybe have a look on the pedelecs forum there maybe some more info there.
Jdsk
Posts: 24639
Joined: 5 Mar 2019, 5:42pm

Re: Refurbing bike batteries

Post by Jdsk »

It's that just after posting moment isn't it? : - )

The 'net equivalent of l'esprit de l'escalier.

Jonathan
stodd
Posts: 708
Joined: 6 Jun 2018, 10:24am

Re: Refurbing bike batteries

Post by stodd »

I'm afraid that is about their power tool batteries. Their ebike batteries are much more complicated; with digital communication battery to battery management system (BMS) to controller. If you lose power to the BMS during a recell process the battery is effectively dead.

It can be done, the expert is (apparently, I've not used him) Jimmy at Insat
https://ebikebatteries.co.uk/
https://bga-reworking.co.uk/
(same company???)

There are several threads on pedelcs site, eg https://www.pedelecs.co.uk/forum/thread ... ath.39669/
That's where I have seen Jimmy regularly recommended.
hemo
Posts: 1438
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Refurbing bike batteries

Post by hemo »

It is now believed that the Bosh BMS doesn't need to have the power kept live during transfer to a new cell pack, though it does communicate using handshaking protocols. A generic non Bosh BMS with a battery can't be used though any type of Li cell can be used as long as the Bosh BMS is used.
stodd
Posts: 708
Joined: 6 Jun 2018, 10:24am

Re: Refurbing bike batteries

Post by stodd »

hemo wrote: 10 Aug 2021, 8:43pm It is now believed that the Bosh BMS doesn't need to have the power kept live during transfer to a new cell pack, though it does communicate using handshaking protocols. A generic non Bosh BMS with a battery can't be used though any type of Li cell can be used as long as the Bosh BMS is used.
I stand corrected on the BMS details.
In fact I see it is even possible to repair the BMS: https://youtu.be/Ia4xe_R0qgw
(pointed out on pedelecs forum: https://www.pedelecs.co.uk/forum/thread ... ost-622977)

It is still correct that repairing/recelling a Bosch ebike battery is much more complicated than work on a Bosch tool battery, or on a generic ebike battery.
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Refurbing bike batteries

Post by simonineaston »

that is about their power tool batteries.
That's correct. My e-bike - a conversion by a company called Nano - uses Bosch's 36v power tool batteries.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Refurbing bike batteries

Post by simonineaston »

Quite good YT video here. Very interesting from the pov of what goes on inside a Bosch tool battery and very short on data, but most educational, nevertheless. :shock: I think I'm just going to splash for a new one, after watching this!
In a way, it's a shame to bottle it when it comes to a DIY refurb, given the potential to enjoy additonal capacity (6 AH plus, as opposed to original 4AH), but I don't have the tools or knowledge / skills to do this.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
hemo
Posts: 1438
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Refurbing bike batteries

Post by hemo »

I build all my ebike batteries using top brand cells from reputable sellers.
My last battery a 6ah 12s LG HG2 12s/2pall shoehorned in to a 82mm ali drinks bottle, it replaced a pair of 7yr old Samsung dolphin case batteries.
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Refurbing bike batteries

Post by simonineaston »

I build all my ebike batteries using top brand cells from reputable sellers.
Nice! In the linked video, you can see the bloke joining the cells together, with strips spot-welded to the ends, using some sort of electric device - do you do the same? Or do you use another technique? What precautions do you take re the potential to get shocked?! Do tell!!
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
User avatar
NUKe
Posts: 4161
Joined: 23 Apr 2007, 11:07pm
Location: Suffolk

Re: Refurbing bike batteries

Post by NUKe »

"Wrap the lithium ion cells in paper and place them in a plastic bag and dispose of them. Lithium cells, unlike NiCad or NiMH, are environmentally friendly and can be disposed of in your regular trash."

But please don't follow this step they can be recycled
NUKe
_____________________________________
hemo
Posts: 1438
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Refurbing bike batteries

Post by hemo »

No shocks from batteries if you are careful, never use any metal tooling except for the electrodes for the spot welding tips , make sure any tools are plastic or wood. Use cut card to temporary cover bare cells once welded.
Don't wear any jewellery, so chains ,rings or watches area no,no.
Jimmy uses a state of the art 30k welding machine, for the diy user one can buy pretty good K-Weld or Malectrics arduino spot welders for les then £200. My Malectric runs off a 3s/12v very high output lipo battery for it's power source. Welds can have the pulse level adjusted to suit power of spot weld depending on the material being used, welds are automatic or can be controlled by a foot pedal. For material I use a pure nickel over copper for the current rating, the diy arduino's don't spot weld copper on it's own very well but add a top piece of nickel with a slit cut in it and the copper welds quite nicely.
Under standing how current and voltage flows and having a digital meter is key.
Lots of good stuff on the Endless Sphere forum in the USA, some very knowledgeable minds on there who experiment a lot.
User avatar
simonineaston
Posts: 8003
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Refurbing bike batteries

Post by simonineaston »

Cheers, hemo - your post is confirmation enough that I would be waaay outside my skillset / comfort zone if I attempted any of this and so it's off to Bristol Batteries on Midland Road it is, instead ! :lol:
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
hemo
Posts: 1438
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Refurbing bike batteries

Post by hemo »

Battery building is possible by the diyer, but a good under standing of safety is need not only in building but over design.
For a one off the expense of diy isn't worth it unless you really like to have ago just because you want to know how to.

For me after building e -bikes it peaked an interest and have since build several ebike batteries as well as other smaller ones for remote power sources for 12v items I use in other hobbies.
Post Reply