Ninebot E+ Li-Poly Graphene battery mod

[litewave]

I have been itching to do the @smallexis battery mod /  @enaon battery mod on a spare E+ for at least 2-3 years. I now have the batteries and time to give it a go. Here are the two battery options available to me:

1. harvest spare 18650 cells from two Ninebot P 340wH batteries that have failed me (cut-outs) previously but are relatively new, or
2. use 4x Graphene Li-Poly in series.

If I harvest the 18650s, I would like to split them into 4 packs of two each: 7S+8S and solder balance lead wires to each.

The graphene batteries (new) are 14.8v (tested and confirmed) rated 6000mAh at 100C and already have balance connectors attached and would be far easier to implement. Combined they are 59.2v @6500mAh. I intend to use manufactured y-cables with XT-90 connectors to merge them into one pack, and make a custom XT-60 to XT-60 + XT-90 y-cable to connect to the control board.

The end goal is to charge all batteries with a hobby charger to better manage/monitor battery health.

Any caveats or warnings on this? Based on my reading of the previous (successful) mods linked above, this should work. I also think the graphene batteries are more than up to the task.

Thanks in advance.

 

Edited March 1, 2022 by litewave
removed photo to reclaim available user space

[enaon]

you can not merge li-ion and li-poly, so I guess you are planning on not using the included battery at all. If you want to use it, this will not work. The bms part is missing from your post too. 

Another thing that is important is safety, small rocks will get trapped inside the wheel, considerations should be made to protect the batteries. I have since placed yet 15 more cells on the other side of the 9bot, and this is what I came up with, it is a "no packing" sign with some resin on top. 

 

 

 

 

Edited April 26, 2021 by enaon

[litewave]

^^^ thanks. I was planning to skip the BMS on the internal 18650s salvaged from the P battery packs and connect them to the existing battery BMS. I think @smallexis did the same. I would disconnect the internal 18650 cells before charging them with the balance leads.

I'm still wondering how to use Li-Polys only without BMS.

Edited April 26, 2021 by litewave

[enaon]

46 minutes ago, litewave said:

I was planning to skip the BMS on the internal 18650s salvaged from the P battery packs and tie it in to the existing battery. I think @smallexis did the same. I would disconnect the internal 18650 cells before charging them with the balance leads.

gotway likes this post

 

I think he had some protection, I am not sure. A 15s bms from ali is cheap and small, and it works. I have 3 packs now, the original and the 2 new ones, 3 bms's in total.  I had a cell fail on me on one of the new packs some months ago, I only noticed because I was getting less distance, the bms worked as it should and disconnected the pack when it fell too low. You need the bms, not for balancing, this will not work with the voltages the nb is set to, but for protection. 

I have followed your cutout adventures due to batteries. I think it's  best to use one bms per pack, and Samsung q30 batteries. This way, each pack will be strong enough to support the wheel by it self, you will have 3x times the safety, and more than 2x the range, it will be well worth the time if you enjoy the E+ I think. 

you will then be able to run it as a p with the speed limit at 30, I can now say, after 3 years with not a single fail, that it works nice

And a photo as an inspiration, 44km wondering in the city, the last part was uphill, and it made it. 

Edited April 26, 2021 by enaon