Understanding LiPo Batteries

Why is looking after your LiPo batteries so important?

In the modern world Lithium Polymer (commonly known as LiPo or li-po) batteries have exploded onto the scene (no pun intended), none more so than the radio controlled market. If you own just about anything that’s an electric powered radio controlled vehicle, it’s almost guaranteed to be powered by some sort of LiPo battery, from the tiny little polystyrene helicopters all the way through to the big 3D helis and planes.

LiPo's have both advantages and disadvantages though, some of the key advantages are size and weight for the punch they pack they are hard to beat, which makes it hard to understand what the disadvantages are, unfortunately though the disadvantages are real and need to be considered, the primary concern is that they can be volatile if not cared for correctly, they only have a limited life expectancy, and some of the larger versions can be expensive, although the price seems to be continuing to drop slowly as higher capacity batteries are becoming more and more available.

In order to care for LiPo's correctly you first need to understand the different markings and ratings on them. LiPo's are split into cells, the number of cells are dictated as 1S for one cell 2s for 2 sell 3s for 3cell etc, in recent years you may have come across a LiPo with the marking 6s2p, since we know the 6s refers to the number of cells, that just leaves the 2p, this would denote the battery is made up of 2 batteries, thankfully in today’s market there is no need to manufacture LiPo’s in 2 pieces.

The next major point is the mah rating, this refers to the capacity in milli ampere hours, so for example a 2000mah LiPo could deliver 2000mah for an hour before its depleted, or 2amps (to convert from mah to Amps divide by 1000), sounds simple enough? It a little more complicated than that though as we have to look at the C rating, this refers to the rate of discharge, so taking our 2000mah example from earlier we know for 1 hour it can deliver 2 amps, this would be a discharge rate of 1C or 1 times its capacity, now with the LiPo’s available today we see 60C and above, the 60C simply means it can deliver 60 times its capacity, so a 2000mah 60c battery could potentially deliver 120,000 ma or 120amps, however if we increase the discharge we decrease the time it can sustain that power for, so we would have to divide the hour by 60 so effectively that battery would only last at best 1 minute before its depleted! In summary S denotes the number of cells, mah the capacity and C the discharge rate.

Now comes the interesting bit, the voltage (if your still awake and I’ve not bored you yet!), each LiPo cell has a nominal voltage of 3.7v but in reality it can be anywh