Originally Posted by Pat Masac
I've got a little project going that I need some of you battery guys to help me with. I'm looking for a low voltage cutoff for a 6s lipo that has no curve or warning but just cuts that battery at a safe voltage not to ruin it. Let me explain why.
Have you considered a solar charger for your 6S LiPo? A simple adjustable linear regulator circuit would do it.
If not, another option would be a little microcontroller with six analog inputs programmed to monitor each cell, and shut off a relay when any cell drops below a safe minimum. Microchip makes a whole bunch of them. Their Pic18F458 is one I've used many times, and in fact am working on a project with one of them right now.
The microcontroller circuitry would be fairly simple. Unfortunately, the software to run it would not. (I did this awhile back for a different project.)
If you just want to monitor the whole battery voltage as a unit, again, a microcontroller would do the job. Just use one analog input and a relay. The software would be much simpler, like one page. Microcontrollers such as the Pic18F13K50 would do it, along with a 5 volt regulator, a few resistors and capacitors, and a relay. The whole thing could be built on a Radio Shack 276-150 circuit board. The PicChip has a resolution of 1028 steps, so that would be a 30 millivolt resolution.
Just to show how much power these Microcontrollers have, that 20 pin 18F13K50 has a manual that covers 410 Pages!