Electric Scooter Forum for Scooter Enthusiasts, Scooter Chargers, and Scooter Mechanics.

Discuss the Xiaomi mijia mi M365 original and pro versions in this forum. Topics include hardware, software, hacking, riding, and everything in between.
By Vyt
Posts
#11771
Hello!

I am new here and love to see fellow scoot loving people.

I was also thinking how to improve this M365 and came up with idea how to add additional battery capacity without adding that ugly case attached and waste feet space on the deck.

Idea is, getting 10 pcs of 16650 type batteries. Found some on Aliexpress: € 3 7%OFF | 1pc/lot 100% Original for Sanyo UR16650ZTA 16650 2500mah battery 3.7V Li-ion rechargeable battery with flat top
https://s.click.aliexpress.com/e/kWZOAm8
They are a bit thinner than usual 18650 and of course has less capacity (2500mah declared). Anyways, plan is to use steering pipe as a vessel, two of those 16650 fits together into it. Also found a suitable bms to fit. My only concern is - do 16650 give enough current to work in scooter? Theoretically load should divide by current on both batteries.

Any insights are appreciated!


#11795
Thats been in my want to list for a while.
My plan is take the mast and aux battery from Segway ES and fit it to replace the mast of a M365. Of course keeping M365 handlebar & dash.
Chances I wont build a new BMS, just take my chances I dont burn down my workshop.
Vyt liked this


#11831
Vyt wrote:
Sat Jun 15, 2019 2:53 am
Found this bms which would fit easily.
https://s.click.aliexpress.com/e/bMqy2TYM

I was thinking to adapt Segways additional battery on M365, but prices of those are terrible.
Your ali links does not open item, just main page for me. Seems because valid for your login only. Give item name.

anyway, perfect, if it fits

standard 18650 does not fit?


By Vyt
Posts
#11853
BMS item name: 10S or 13S small size 36V lithium PCB or 48V BMS for electric li-ion battery with 15A constant discharge current

Batteries: 1pc/lot 100% Original for Sanyo UR16650ZTA 16650 2500mah battery 3.7V Li-ion rechargeable battery with flat top
Saw some reviews, people were testing them and claimed they're fine. Capacity is approx as declared. I might give it a shot. But still, I'd like to get some opinion from battery specialists To view images REGISTER or LOGIN for full access.

That's some review I found: https://www.candlepowerforums.com/vb/sh ... -(Magenta)

And no, unfortunately 18650 doesn't fit. The pipe is too short for 10pcs 18650, but long enough to fit 5 pairs of 16650.

By Dog
Posts
#11862
The problem with this is that they have quite different ah. 7800 and 2500, so the voltage of the 2500 will drop before the 7800 causing it to charge the 2500. I know this results in less efficiency due to the heat wastage, how significant it is I don't know. I'm not sure whether this damages the battery or not. Maybe someone with better knowledge can comment as I'm also interested!

By Vyt
Posts
#11882
Dog wrote:
Mon Jun 17, 2019 12:53 pm
The problem with this is that they have quite different ah. 7800 and 2500, so the voltage of the 2500 will drop before the 7800 causing it to charge the 2500. I know this results in less efficiency due to the heat wastage, how significant it is I don't know. I'm not sure whether this damages the battery or not. Maybe someone with better knowledge can comment as I'm also interested!
That's not how it works. Its all about current. When there is a voltage decrease on one battery, the current will be drawn from the battery with higher voltage. Voltage should remain equal and in balance between both batteries.

By Dog
Posts
#11886
Vyt wrote:
Tue Jun 18, 2019 3:21 am
Dog wrote:
Mon Jun 17, 2019 12:53 pm
The problem with this is that they have quite different ah. 7800 and 2500, so the voltage of the 2500 will drop before the 7800 causing it to charge the 2500. I know this results in less efficiency due to the heat wastage, how significant it is I don't know. I'm not sure whether this damages the battery or not. Maybe someone with better knowledge can comment as I'm also interested!
That's not how it works. Its all about current. When there is a voltage decrease on one battery, the current will be drawn from the battery with higher voltage. Voltage should remain equal and in balance between both batteries.
Yes exactly, the process by which the voltage remains the same and equal in both batteries is by the larger one charging the smaller one.

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