I broke down and finally added electronics to the old R5eIII. Here are the Cell Log 8s mounted up inside the tank.
I got them from the Hobby King, and they give you the cell voltage levels, logging, as well as under and over-voltage alarms. They were pretty cheap at the time, but it looks like they’re a little more pricey now – about $28 each.
For now I have them mounted so you plug them in to turn them on, since I’m not aware of any effective switching for them. I’ve read that you can switch the negative “ground” lead (the red), and that will cut the drain a bit, but leaving the rest of it gets the cells unbalanced eventually. Setting them to “Sleep” mode apparently doesn’t do much at all. I’m not too worried about it, I’m just using them on occasion when I want to take a look at the pack.
The strategy, to review, is to “bulk” charge the pack regularly, and then balance-charge each cell once in a while as needed. So this will tell me when that’s needed.
The Cell Log 8 instruction manual? Let’s just say it’s a product from China and leave it at that. But here it is: cell_log_8s_manual. The software to handle the logging is Windows, of course, and German at that. I’ve messed with it a little, only enough to pretty much give up on it until I need it. That’s here: LogView.