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  1. P

    DIY Capacity test battery packs

    Hi john61ct On consideration I'm going to continue this side project but it looks like the DIY route has headed beyond my capabilities. I'll still use my contraption to drain the odd battery for storage or something. I was going through your links earlier and was interested in this...
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    DIY Capacity test battery packs

    I thought so too lol. Strange my wife's reaction was not so warming when she discovered it on the outdoor dining table.
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    DIY Capacity test battery packs

    Ah ha, thank you for taking the time to reply in simple, understandable terms - it makes more sense now. I now know what is missing on this little adventure - keeping the load at a constant current for accuracy. I cannot test the same pack as it wears out accurately without a constant static...
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    DIY Capacity test battery packs

    Hello all I have built a DIY battery capacity tester and as i’m not electrical engineer I wanted to run a few things by you before I test my good battery packs as there are a few things I don’t understand. I’m using a watt meter to measure the current flow. The load is from oven, stove and oil...
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    8FUN motor needs help to get spinning

    So it definitely was the hall sensor as now the motor starts to spins from any position and ran perfectly during a ride. And the sensor works fine even though it has different behaviour to the existing two, which I didn't bother changing. During discovery and testing, the existing two sensors...
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    8FUN motor needs help to get spinning

    You were right, at least I think so, by my diagnosis, which could be wrong. Just like to say this forum is amazing, 2 days ago I knew nothing about Hall Sensors and now I'm attempting to replace one. One hall sensors voltage did not change when I placed a magnet over it. The other 2 went from...
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    Battery not charging BMS voltage lower than battery total

    Just to update, it was the BMS's that had failed across all 3 batteries. Replaced two of them and they have been working well.
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    8FUN motor needs help to get spinning

    I cleaned up a 8FUN front 250w geared hub motor that was badly rusted internally, I mean really badly. I'll post some pics later. After the clean up, it ran fine on the bike for a few days. After briefly stopping on a ride, I set off again and the motor was noisy and ran rough for a short while...
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    Turn 48v battery into 36v after removing bad cells

    Hi, I have a 48v 13s5p battery pack. It had 3 bad banks which I've removed. I'm left with what is shown in the pics with all banks around 3.6v. I'd like to make 3 12v batteries which I'll run in series. To charge them I have 2 iMax B6 hobby chargers so I'm thinking of wiring up balance leads...
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    Battery not charging BMS voltage lower than battery total

    I'm picking up a genuine iMax B6 charger tomorrow. Having never used a hobby charger I suspect it'll be a big learning curve to get going. My plan is to balance each bank of 13 cells to 4v (as they are near this currently) by manually plugging 2 pins into the balancing port connector of each...
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    Battery not charging BMS voltage lower than battery total

    The two wires looped from the BMS connector, is this a single non-spliced wire? Yes it's a single looped wire from Port 15 go 16. With some manual balancing on one battery I got all cells within 3.98 and 4.04v. I then connected each BMS to this pack. Each read out roughly half the voltage of...
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    Battery not charging BMS voltage lower than battery total

    Thanks for the tips on the BMS. My controller is rated at 18amp and my motor is only rated at 250w. I may build another ebike with a mid motor so may get one with higher than 18amp, maybe around 25 to 30 amp. Is that OK? I'll get one BMS as my balancing charger idea doesn't sound that easy...
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    Battery not charging BMS voltage lower than battery total

    Thanks I thought it was weird all would be the same, but it does show how little I know hahaha. This is where I read it https://www.elecycles.com/blog/post/how-to-diagnose-the-lithium-battery-bms-damaged-or-the-battery-cells-damaged/ I see they do say within range not the same. Is that correct?
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    Battery not charging BMS voltage lower than battery total

    Yeah my first post was in reference to the first battery at 52.5v. The second battery has two 0.6v banks which I won't use so that one I'll be tearing apart for another project. Another reason I'm keen on an adjustable balancing charger. The third battery was at 42v. I'll try what you...
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    Battery not charging BMS voltage lower than battery total

    I'm now thinking i may buy a good battery charger that can balance the batteries, etc. As I have to buy 3 BMS for the battery packs and as I don't know the history of these batteries would it make sense to rather buy a good charger so I can monitor the cells from the led? I would feel more...
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    Battery not charging BMS voltage lower than battery total

    Thanks, that's not too long of a wait. I just counted and I have 16 balancing wires. B0 and the last 2 wires in a loop. Will try find one that matches up.
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    Battery not charging BMS voltage lower than battery total

    Many thanks for the links. I've never bought a BMS before, is there anything I need to be aware of? Would the above two works with my specs... My specs are 48v 13Ah Cells are Samsung ICR18650-26H M there are 65 cells Be great if the BMS port that links to all the battery wires just plugs...
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    Battery not charging BMS voltage lower than battery total

    I've just opened up the final 3rd battery pack and it's measuring 18.9v at the charge port and 42v across the batteries. Another pattern I have noticed across all 3 batteries: For the third pack I've just opened as an example, measuring the cell banks from the BMS port, the first 9 banks...
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    Battery not charging BMS voltage lower than battery total

    The results from measuring where the connector goes into the BMS are: 9 cell banks at 4.05v 3 cell banks at 3.925v 1 cell bank at 4.13v So they are out of balance but would that cause the above symptoms? They are Samsung cells. I was under the impression these packs were not cared for and...
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    Battery not charging BMS voltage lower than battery total

    Hi guys I'm in need of some help as I'm completely new to ebike batteries and troubleshooting them. I've learnt loads today and won't do anything I don't understand... I have 3 48v 13ah batteries and 3 chargers. None were charging so I have opened 2 of them up. From the BMS: The battery...
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