Foolish battery builder question


New Member
United Kingdom
Hi All.
New to ebikes, always wanted one. Im a 30 year full bike licence holder and never driven a car. When not on two wheels I get the train to work.

Recently got a job where the journey was a bit of a challenge on foot and train. I usually walk 1.5 mile to station then a mile to work and have been lucky to be able to do this since 2015 despite having a few differeny jobs.

My latest job 1.5 miles to station and 3 miles from end station to work so I bought the cheapest ebike Halfords had which was the 20 inch wheel assist ebike. I figured on on a packed train its small size would cause less mither. To be honest its not much smaller than a regular bike, has no gears, and the battery seemed to struggle after the five mile journey.

I had a brain wave, bought another pack for 50 pounds off fleabay, and basically doubled the cells in the pack. The cells rated at 1.2volt. Anyway its been charged up a couple of times now and Ive got power to spare and a lot less battery sag.

My question... this.

After parking up the bike over the weekend I came to charge it yesterday and the charger light was green. The cells had recovered enough in 2 days to trick the charger into thinking it was fully charged.

I had to go out and ride a mile or so on it, come back and plug charger in at which point it took 3 hours to charge.

Does anyone have any comments, advice, is this normal for a 24v 4p7s pack? Its got 14 brand new cells in it and 14 ebay cells in it. I was lucky to find the ebay pack had 14 batteries and another14 empty battery spaces in it. A few hours later I had broken down the new pack and was soldering the batteries into place using the strip tags.

Am I foolish? I read of people reclaiming batteries all the time.

By the way, i keep the battery in an amunition box when not in use, bolted to the back of the bike. If it explodes it will either be in the box or in use. If its in use I could get my ass blown off lol.

People may laugh at me, but so far this bike has took 2 hours off my journey. Im fairly competent with a soldering iron, a bit of a screwdriver expert, but I also worry a little bit.

I expect no one could tell me its 100% safe but I was suprised to see the pack recover as much as it did. Batteries dont get warm when charging or in use now either. Surely thats good right? 2amps into 2 packs rathet than one etc.
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Am I foolish? I read of people reclaiming batteries all the time.
Dangerous especially soldering packs. Lots of claims never followed up with failures. There is a solder technique using goot wick but needs a really good choice of soldering irons and fast work. This isn’t the same as building solar charged systems with salvage. Watch for deals on salvage battery sites selling quality cells. Run don’t walk away from cheap eBay cells and packs.