$10 DIY Smart Charger Alternative / Ver. 2.0

[Gionnirocket]

Cool little circuit you’ve assembled. I totally agree that hacking is part of the fun. I hack other thing last for the same reason. I may use this for my 36v battery. Maybe I can use the same unit for a 36v battery and a 48v battery. Though, at the price, maybe I’ll make a separate one. I like to monitor my charging.

Depending on your use between the two batteries. . .
Very easy to adjust voltage and I've set it up so it's easy to swap out charger and battery input/output connectors. But if I had to change back and forth daily I'd definitely build 2 for convenience.

 

[Gionnirocket]

With a new bike and battery I had to update my charge adapter similarly to the mod' @rounds had to make.
The safety features of the Zen battery does not output voltage on the battery charge port unless it receives a handshake from the charger.
So I had to install a momentary contact switch which needs to be held for 2 seconds to initiate the charge... then it's all automatic to my desired SOC as before.


Special thanks to @Zen Support for helping with the necessary cables as their proprietary 3 pin Julet connector was impossible to source.


One question for Mr. @Ravi Kempaiah...
Is it correct to assume that Watt-hour in equals Watt-hour out?
Example...
If I charge to 50.0V
Then ride 20 miles.
Then charge to exactly 50.0V again with a total of 155Wh being input back into the battery.
Can I divide the Wh in by miles driven to have a fairly accurate Wh per mile?
(155Wh/20mi = 7.75Wh/mi)

 

[Ravi Kempaiah]

With a new bike and battery I had to update my charge adapter similarly to the mod' @rounds had to make.
The safety features of the Zen battery does not output voltage on the battery charge port unless it receives a handshake from the charger.
So I had to install a momentary contact switch which needs to be held for 2 seconds to initiate the charge... then it's all automatic to my desired SOC as before.
View attachment 173481

Special thanks to @Zen Support for helping with the necessary cables as their proprietary 3 pin Julet connector was impossible to source.
View attachment 173482

One question for Mr. @Ravi Kempaiah...
Is it correct to assume that Watt-hour in equals Watt-hour out?
Example...
If I charge to 50.0V
Then ride 20 miles.
Then charge to exactly 50.0V again with a total of 155Wh being input back into the battery.
Can I divide the Wh in by miles driven to have a fairly accurate Wh per mile?
(155Wh/20mi = 7.75Wh/mi)
View attachment 173480

Wh - in will always be > Wh - out.
There are inefficiencies with every charger, and it is safe to add 5-8 % buffer to compensate for that.

 

[Gionnirocket]

Wh - in will always be > Wh - out.
There are inefficiencies with every charger, and it is safe to add 5-8 % buffer to compensate for that

Thanks Rav'
Yes I'm aware of charger inefficiencies... but I'm measuring Wh -in post charger so the charger inefficiency are bypassed and the remaining concerns would be the wiring, the BMS and the internal resistance of the cells.
Since the generated heat in these areas is negligible (as far as I can tell)
Do you think the buffer lower (1%)... or am I assuming incorrectly?