Originally Posted by
breadbin
Thanks for the advice, I did try one car battery and it didn't do anything so I guess it probably would take 4 which I don't have and which I won't even try. I am guessing that there might be 18650 cells in it, if so I can try and get fresh ones and replace the ones inside. I haven't been able to get to the bike shop because the car is out of action, that's actually why I was trying to charge the electric bike!
I think you are right that it will probably be 18650s inside. And I think that they will be okay if charged.So if you can dismantle the battery and put the individual 18650s in a 18650 charger then you should be able to charge them up and put them back in the pack without having to purchase new cells.
One issue may be that individual cells are usually welded together with nickel strip. I have recently purchased a welder and nickel strip from China very cheaply for precisely this purpose but I have not tried it yet. It is said to run off one car battery. Details below this photo with link to aliexpress
Battery Welder by
Timothy Takemoto, on Flickr
But cutting apart your battery, charging the cells individually, and then welding the cells back together sounds very time consuming.
As mentioned above, I guess that there is more than two battery terminals but Googling the battery, it seems that only two of the terminals are made for charging so you are going to need more volts or get a new battery.
The batteries for the Carerra Impel 1 (there is also a Carerra Impel 2 ) are 36v cost 200UKP from ebay.
https://www.ebay.co.uk/itm/394509832421
There are videos on YouTube of people trying to get 18650 batteries to explode and or catch fire. They succeed but it is clearly not all that easy -- e.g. a fully charged batter, a hammer and a spike -- to get them to explode / catch fire.
So I dismantle laptop battery packs with a screwdriver watching the sparks without much fear. I have about 40 18650 cells harvested in this way.
Good luck