SOS 74v 30Ah Lithium-Ion battery repair

#21

I would agree with you Joe! but thing is I did buy another one which is not “limited”, and has a peak performance of 6000W as they said and it’s got even slower max speed then the original… however acceleration was amazing :slight_smile: - was even thinking about replacing the micro controller with custom software but that’s even a bigger project… as first I would need to analyse how the signals are used and generated… and so on

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#22

I would be happy if I wouldn’t have to buy more battery cells, a new BMS and a charger for this, as the lithium-ion battery pack itself was about 700 pounds

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#23

The limiting factor may be the output devices or the motor inductance or a whole host of things.

This sort of thing was rocket science a few years ago. What I am trying to say is it might be a bit more difficult than just pumping up the voltage.

If you catch me in the space I will be happy to help

#24

Do you have a drawing of the controller?

#25

I don’t have a circuit drawing for any of the controllers :frowning:. but I can drop by with the one I’m not using currently

#26

They are probably based around a chip jus get the datasheet

#27

:slight_smile: probably… But I was not able to find the datasheet :frowning:

IMG_20170530_202922.jpg2610×4640 1.37 MB

#28

It’s a 16 bit nec microcontroller.

Its all in software

#29

Thx… Got it.
Maybe I can replace it with an Arduino ?

#30

Probably not powerful enough .

There’s a good application note from microchip An857

Google "microchip an857 "

Happy reading :grinning:

#31

Brushless motors are rated in revs/volt so more volts = more revs. The current (amps) is the horse power…
volts x amps = watts so that’s the correlation.

I’m back in the uk and should be at the space for Thursday Electronics!!

Courty

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#32

Sarcasm is the lowest form of wit :grinning:

At 6kw I am pretty sure it is not that simple.

But if it is i am prepared to eat my hat …

#33

While it is an over simplification, fundamentally the above is true !

Courty

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#34

I definitely got the inpresion that the limiting factor was not the motor inductively, I got the inpresion that it was probably the inverter, but I will still Google what goes best with hat

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#35

okay… I talked to the guy I bought the controller from and he advised not to increase the voltage above 80V. Now max voltage on the li-ion battery is already 84 volt and it gave me 1 mile of increase in speed. So bad news is if I want to increase the voltage I’ll need more cells, a new BMS and a new controller… not the news I was expecting as this will cost another few hundred pounds :frowning: