building first pack using N.E.S.E system 10s8p

Batteries, Chargers, and Battery Management Systems.
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barnaby81   1 mW

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Joined: Jan 09 2017 6:31pm

building first pack using N.E.S.E system 10s8p

Post by barnaby81 » Dec 12 2018 5:55am

ive got through a couple of shop bought packs and i have been thinking about building a pack for myself for a while, and like the concept of these modular units.

i have bought all the bits i need except for the cells.i ride at about 15a@36v(540w) give or take. i live in the uk and want to buy quality cells, probably from nkon. is there any point in me buying 30Q cells over 29E cells as i think i pull 18A@36v max? Even with the 29E 8a approx that gives me 64a in a string of 8p. i want to charge this pack at 8A (C/3). i do not expect to get any more than 500 cycles but i haven't done that on any pack yet. i normally charge at C/7 but if my pack only last to 500 cycles anyway...

could someone who has done this before comment on why i should spend double the amount on cells except for the 4ah extra i get using the GA or 30Q compared to the 29E. Or is there a fundamental flaw in my thinking?

cheers

whereswally606   100 kW

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Re: building first pack using N.E.S.E system 10s8p

Post by whereswally606 » Dec 12 2018 9:41am

My friend Joel and I built the exact NESE pack you are i.e. 10s8p so 80 cells
he chose LG INR18650-HG2 3000mAh - 20A as he wanted capacity and current draw. He runs two 250w hub motors the 100h type ones from bms battery.

using a server power supply and the cheap step up dcdc which supposedly can do 15 amps we didn't see over 10amp charge rate in reality.

I think you are fine to go with the 29E cells. I also see one purpose of the NESE kits is that once your cells don't perform well enough for your bike anymore you can take them out weed out the dying ones and repurpose them for stationary storage. By that time better cells will be on the market and prices will have dropped.

anyway good luck and my friend seems very happy so far with the packs cable tied to his scott ransom.

Be careful when putting the cells in the NESE cases, I nicked the end of one when putting in the last cell in a subpack at a slight angle and the cell caught fire. In essence I shorted the terminal with the case and it welded a bit of metal bridging the anode and cathode. Was like a roman candle firework which was fun to watch but also bloody scary. This shouldn't happen if you are careful and put it down to user error.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

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MJSfoto1956   10 kW

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Re: building first pack using N.E.S.E system 10s8p

Post by MJSfoto1956 » Dec 12 2018 9:59am

whereswally606 wrote:
Dec 12 2018 9:41am
...I nicked the end of one when putting in the last cell in a subpack at a slight angle and the cell caught fire. In essence I shorted the terminal with the case and it welded a bit of metal bridging the anode and cathode. Was like a roman candle firework which was fun to watch but also bloody scary.
Please post photos of the aftermath if you have them!

M
EVs have fewer externalities than ICE vehicles. In the long run, it is the only way forward.

whereswally606   100 kW

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Joined: Jun 19 2011 2:11pm
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Re: building first pack using N.E.S.E system 10s8p

Post by whereswally606 » Dec 13 2018 3:40am

sorry I don't and it didn't completely burn. it just shorted until I managed to get the metal which had welded itself between the +ve and -ve to disconnect. after that it was fine (hot but ok) just didn't feel like it was smart to use it so we bought another instead.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

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