Introduction

edepa

New Member
Region
Europe
I've just joined and have come to pay respect :)

I'm from Malta, and have been biking for decades.
Given the intensity of Summer here, and that I pedal to work, I'm switching to an eBike for Summer.
I've acquired an old Pharos forenzo bike (1995?) and am currently working on assembling a replacement battery pack.

Cheers,

Etienne
 
Welcome to the Forum!

A 1995 e-bike? Etienne, please accept the fact e-bikes have slightly changed over the past 29 years... (A Ni-Cd battery?!)
Hello Stefan - yes, you're right about the battery being Ni-Cd. I've bought NiMH replacements, a spot welder, nickel strips and am now looking for a suitable inter-battery glue, apart from the heat-shrinkable wrapper around the whole assembly.
 
Hello Stefan - yes, you're right about the battery being Ni-Cd. I've bought NiMH replacements, a spot welder, nickel strips and am now looking for a suitable inter-battery glue, apart from the heat-shrinkable wrapper around the whole assembly.
If you think the effort is worth of it, I can only wish you good luck. This e-bike is a real hot rod! :)
 
I've bought NiMH replacements, a spot welder, nickel strips and am now looking for a suitable inter-battery glue, apart from the heat-shrinkable wrapper around the whole assembly.

What about an upgrade to lithium cells?

The new 21700 cells have come way down in price.

Screenshot_20240828-154524_DuckDuckGo.jpg



Just make sure that you buy original Samsung, LG, or Panasonic cells, with an appropriate BMS and charger, and you're good to go, without any safety issues.

I bought this stuff for gluing inside my battery,..
It's the "Proper" stuff to use.

Screenshot_20240828-155123_Amazon Shopping.jpg



Clear Electronic Grade Silicone - 2.8 oz Squeeze Tube https://a.co/d/0bLoSh5
 
What about an upgrade to lithium cells?

The new 21700 cells have come way down in price.

View attachment 181281


Just make sure that you buy original Samsung, LG, or Panasonic cells, with an appropriate BMS and charger, and you're good to go, without any safety issues.

I bought this stuff for gluing inside my battery,..
It's the "Proper" stuff to use.

View attachment 181280


Clear Electronic Grade Silicone - 2.8 oz Squeeze Tube https://a.co/d/0bLoSh5
Thank you for tipping me off about the battery glue !
When I dismantled my NiCd battery pack, I removed one battery from the assembly to gauge the adhesive strength (picture below).
Whatever the glue used was, it was hard to prise one 32600 free ... do you know whether the product you've suggested has that strength of adhesion?

Cheers,

Etienne
1724938860248.png
 
I opened up my battery then used some of that glue to close it up again.
I found a little circuit board inside that could bounce around and I wanted to stabilize it.

20230413_201904.jpg
20230413_202153.jpg



My battery cells are wrapped in what they call "fish paper" and I don't know what it looks like under the fishpaper.

You can also get plastic separators and the cells "plug" into the spacers to keep them separated.

You don't want any rubbing between cells that can wear through the plastic shrink wrap and short out the cells.

Vibration can also stress the nickel strips and they can break (metal fatigue) or a weld can break.

Changes in heat can also cause metal fatigue due to expansion and contraction.

You can also get circular stickers with a hole that go on the positive terminal of each cell to help prevent a short circuit across from the positive terminal to the cell casing a mm away or from the nickel strip that could touch or wear through to the negative case of the cell.

Another thing I remember is that Ni-Cd batteries are supposed to be drained fully before charging or they develope a memory.
I don't know if NiMH have a memory issue or if the cell voltage is the same as Ni-Cd ?

I found the owners manual for your e-bike and it looks like the charger has a setting to drain the cells before charging to prevent the memory effect.
That may not be necessary for NiMH or even bad for the cells?

So you've gotta look into charge rate (amps) as well as charge voltage.


The main things about the glue is that you don't want it to melt if it gets hot, and you don't want it to give off any gasses that can damage sensitive electronics.

Regular Silicone 1 gives off acetic acid during the cure and that's not good for sensitive electronics
Silicone 2 doesn't stink when it cures, and as far as I know, it should be fine for your battery?

I was messing around with a lithium battery so I wanted to use the proper stuff.

The original white silicone inside the battery was pretty good strength of adhesion but I could still careful pull the wires from it.
Regular silicone is a bit stronger, and I probably would have broken the wires?


The stickers go here, under the nickel strips.

1724938860248.png
 
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When I did not know better, I messed with batteries. Say, No, No, No. And a really great young man Gregory died in my town recently messing with stuff he shouldn't. That said I did awaken a sleeping BMS this week, safely. It is like playing with petrol. Easy to become complacent.
 
I learned in school how to mess with batteries.
I've revived dead NiCad batteries by connecting them to a car battery.

I've also set my cars gas tank on fire, and myself on fire half a dozen times.

NiMH batteries are much safer than lithium.


Screenshot_20240829-202214_DuckDuckGo.jpg



s*it always happens though.

This is the hand of a guy who messed with a lithium battery,..

IMAG0258.jpg



Do your homework and follow the protocol and keep safety in mind.
 
When I did not know better, I messed with batteries. Say, No, No, No. And a really great young man Gregory died in my town recently messing with stuff he shouldn't. That said I did awaken a sleeping BMS this week, safely. It is like playing with petrol. Easy to become complacent.
Please keep in mind that batteries are made by people; experts, admittedly. Some of us might be experts, others might not ...
 
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