CAN BUS more Features

Hi Stuart,

the can bus connection works fine.
Any chance to implement more steps for overvoltage?
E.g: after overvoltage alert on one cell max chage current down to xx V.
( This works in the moment. )
But when the cell is recovered below limit voltage ESP gives Vicky a signal and immediately I have high charge Amps.
Better would be:
A settable time delay before the high charge condition is allowed to regain.
And more steps.
Eg.:
32A normal load
During overvoltage 1,5A. If this fits for a time back to 16A
If the overvoltage reappears down to 1,5A again.
Next attempt at 8A.
And so on…
Vice versa when the lower charge generates no overvoltage for a time.
Switching up to higher Aps.

This would regulate at the end of the day the battery to be charged longer with higher rate.
And after the night when the battery is used it may start with higher rates automaticly.

Any chance for more regulating?

Hi. What inverter are you using? By the sounds of it you are explaining what CC and CV.

As batteries charge for the initial stage its called Constant current or bulk charged. Then as the cells reach their upper charge limit most inverter chargers switch to Constand Voltage CV or known as absorbtion phase. This is where your charger starts the back the current off.

Stuarts diybms could do this but generally most inverter chargers have cc and cv algorithms built in.

Post some info aboutyour set up and maybe we can help with the settings first off.

Whats your battery voltage. What chemistry battery you using?

I use a Victron Multiplus II GX 3000.
First I used it without CAN of the DIYBMS.
The Multiplus charges the battery CC until the demanded voltage is reached.
Then it goes to CV. Unfortunately it has no idea about the unique cell voltage.
The voltage is reached but it may be one cell blows, another has undervoltage.

Thats the reason why I use the CAN BUS connection.
The DIYBMS tells the Victron to change CC when an OV occurs.
In my setup from 16A to 1,5A. The cells get more time to blance.

But as soon as all cells are back in the blue area DIYBMS switches back to 16A.
And the OV occurs in the next minute again.

I would like to have steps to switch up a higher CC than the 1,5A after OV in a cell.
But not as hight as the 16A before OV occured. Maybe only 8A.
To accelerate charging but prevent immediate OV again.

I use LiFePo4 prisma cells.