Ninebot S2 with DIY battery packs???here my reasoning to how to...

[alex87]

hi to all, my first post, my first EUC....... and i bought from amazon ITALY a ninebot S2.

why the s2? because i read that it has 2 batteries under 160w and i COULD bring it on a plane...... and because i APPRECIATE external batteries instead of built in.

As a flashlight enthusiast.. and everything about batteries etc, i find that one person could build by itself a batetry pack, am i wrong?

THis model should use 2x batteries and each one should be of 15 x18650 batteries. right?

i also supose that the FINAL CONFIGURATION should a 15s2p battery ( both packs) so it should be relatively safe, i read that the voltage is 54,3 (medium voltage nominal) so i can think it is 54,3 / 15 batteries = 3,62v that's the CLASSIC VOLTAGE of a 18650 lithium

in fact the WALL CHARGER is rated for 63volt...........so it can charge 15series of 18650.

My idea would be to use 4x of these holders 

(of course minus 1 battery to be 15 of total) and buymyself 15x 18650 batteries , the connection cables should not be a problem i think, but my only one CONCERN, is how to CALIBRATE 15 batteries!!!

i know that there are balance cables but i know they reach at max 8x batetries in series, and there are hobby chargers that can handle up to 6x balanced batteries in series.

So could someone say me how is made the charging cirtuit of a EUC ?? how could it properly balance 15 batteries in series ? maybe... he uses 5x 3 blocks of cells to be balanced.. i don't know.

or maybe..............they NEVER BALANCE THE ENTIRE PACK.... but doing so the overall life of it will decrease over time.....

[Chriull]

34 minutes ago, alex87 said:

hi to all, my first post, my first EUC....... and i bought from amazon ITALY a ninebot S2.

Welcome & much fun with your EUC!

34 minutes ago, alex87 said:

why the s2? because i read that it has 2 batteries under 160w and i COULD bring it on a plane...... and because i APPRECIATE external batteries instead of built in.

This COULD was quite some time ago - by now most airplanes refuse transport of EUC's, hoverboards, etc... No matter if with or without battery...

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My idea would be to use 4x of these holders 

That's absolutely not recommended - they cannot stand the necessary current and every contact failure lets your S2 stop immedeately.

 

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(of course minus 1 battery to be 15 of total) and buymyself 15x 18650 batteries , the connection cables should not be a problem i think, but my only one CONCERN, is how to CALIBRATE 15 batteries!!!

i know that there are balance cables but i know they reach at max 8x batetries in series, and there are hobby chargers that can handle up to 6x balanced batteries in series.

So could someone say me how is made the charging cirtuit of a EUC ?? how could it properly balance 15 batteries in series ? maybe... he uses 5x 3 blocks of cells to be balanced.. i don't know.

EUC's normally use a BMS which has the charge "control" - the charger itself is just a current source up to max cell voltage and then a constant voltage source.

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or maybe..............they NEVER BALANCE THE ENTIRE PACK.... but doing so the overall life of it will decrease over time.....

?Some?/The BMS have/has a balancing circuit integrated, which gets active in the last phase of the charging process (once the charger delivers the constant max voltage and current dropped below a certain threshold (somwhere around ~100mA?))

Edited July 14, 2017 by Chriull

[smallexis]

3 hours ago, alex87 said:

THis model should use 2x batteries and each one should be of 15 x18650 batteries. right?

i also supose that the FINAL CONFIGURATION should a 15s2p battery ( both packs) so it should be relatively safe, i read that the voltage is 54,3 (medium voltage nominal) so i can think it is 54,3 / 15 batteries = 3,62v that's the CLASSIC VOLTAGE of a 18650 lithium

in fact the WALL CHARGER is rated for 63volt...........so it can charge 15series of 18650.

Right but you need to have an original NINEBOT 15S BMS if you want you battery will be recognize by your wheel.

3 hours ago, alex87 said:

So could someone say me how is made the charging cirtuit of a EUC ?? 

This is an example for the charging circuit (C+ and C-) with a 16S BMS (it's the same for a 15S BMS) and power circuit (P+ and P-)

Each cell (or group of parallel cells) are balanced individually. In this case only over charge protection is active (and it's safe).

[zlymex]

On 2017/7/14 at 11:39 PM, alex87 said:

how could it properly balance 15 batteries in series ?

I use a cascadable 4-cell balancer when DIY my own external pack.


https://www.aliexpress.com/item/4S-4-2v-li-ion-balancer-board-li-ion-balncing-full-charge-battery-balance-board/32811548126.html

 

Edit: in case an odd number(other than multiple of 4) of cells, a 3series version is available, and can be split into two single-cell circuit, and appended to 4-cell one making an 5-cell balancer as below. This is one of 4 of my 780Wh external pack: 

Edited July 17, 2017 by zlymex

[alex87]

thank you for all the infos... 

but the most important thing atm is learn to ride it XD

[smallexis]

On 7/15/2017 at 7:23 PM, alex87 said:

thank you for all the infos... 

but the most important thing atm is learn to ride it XD

yes First you have to learn and Second you need capacity in order to have more fun

[Matahalii]

Hey folks! I am thinking of external battery pack(s) for my S2 to increase the range. Making the battery pack(s) with BMS is not the problem now, connecting them would not be either, but where to put them? Can anyone think of a solution other than making an extension cable and carry them in a backpack? I guess there is not enough space under the hood for placing 2x15 solo cells and the BMSes like one did with 15 cells in the Ninebot E+.