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How to read battery percentage?

battery
voltage

#1

I have two e-boards, both with zippy 6S batteies. Both boards have lipo battery indicators that convert the voltage into remaining capacity, but something I noticed is that both indicators don’t drain in a linear line. When the battery indicator gets to 50%, the reading starts to drop quicker. By the time it gets to 30%, it is only a matter of a couple minutes before it reaches 0%.
The indicators are different brands completely and they suffer the same issue.
Any thoughts on how to accurately read capacity remaining?


#2

Those are accurate. The lower the voltage the faster it drops.


#3

is there any smart battery indicators that counteract this to make a linear drop? Smartphones and other lithium powered devices decrease linearly.


#4

Not that I know of.


#5

I use HobbyKing’s HK-010 Power Analyzer - it measures cell voltage and percentage remaining. It also balances your cells, so that you can maintain healthy batteries. I’m not sure if this will help you? :slight_smile:


#6

The phone’s battery indicator percentage might decrease linearly, but the battery voltage doesn’t, which your battery indicators are showing.

In the below picture is the discharge curve for a LG MJ1 Li-Ion 18650 cell.

The voltage is pretty linear in the 100% - 20% after which it will very quickly drop down. A better way to figure out how much battery life you have left based on your indicators is to charge the Li-Pos with a charger that can show how much capacity it has charged back.

Zippy batteries are Lithium chemistry.


#7

So its basically a monitor and a bms? That would be awesome.


#8

Not simultaneously, you can balance the cells when the battery isn’t in use/under load. It is an epic piece of kit, though :slight_smile: