Has anybody tried LT3081 regulators in series to charge each battery independently in a series of batteries? I'm thinking of a simplified version of the circuit using TL431 which performs the same function here

The LT3081 floating regulator which has 1.5A output avoids the need for external transistor to boost current as is used in the TL431 circuit and the Imon pin sense draw current/5000 & regulates output current proportional to the current draw of the battery while charging. It has reverse battery & reverse current protection.

I'm looking to go this route mainly because I may connect to some of the series batteries for different & multiple output voltages & wanted to keep each battery balanced & fully charged

Am I missing anything in my thinking?

 

Transistors T1,3,5 will just blow up as they will short out the batteries...

 

Transistors T1,3,5 will just blow up as they will short out the batteries...

As the battery voltage rises and hits the TL431 threshold, those transistors will begin to turn on and divert charging from the batteries. They will only be passing the charging current. If the battery voltage begins to fall they will turn off again so they cannot 'short out the batteries'.

This circuit will not prevent overdischarge so it only covers half the problem.

 

Sorry, I haven't explained myself well - the TL431 schematic was just given as an example of how the TL431 floating regulator (no ground pin) can be used without floating supplies i.e. just one overall supply but each TL431 unit of the schematic is charging/balancing one battery in the series.

My thought was that LT3081 is a floating regulator just like TL431 & therefore could be used connected in series with each LT3081 charging its equivalent battery in the series - just like with TL431.

I'm not that worried about overdischarge for a number of reasons

 

I'm not that worried about overdischarge for a number of reasons

You have asbestos skin and live in a cave?

 

You have asbestos skin and live in a cave?

I didn't say what battery chemistry I was using & anyway there are easy ways to cutoff discharge at set voltages.
I'm specifically only interested in what I stated, not a full solution.

 

Actually I see the TL431 circuit was originally posted on this forum here so maybe that's where I should continue the conversation?