When to retire LiPos!

[gtranquilla]

I am hoping there is a simpler way to determine when to retire the LiPos on my MR. Is there a direct correlation between battery line loss and battery internal resistance? If so I am hoping to gauge battery retirement by means of the later. The DJI method for retiring batteries requires multiple steps involving DJI Assitant software including reconfiguration of the battery protection levels between two or more flights. Step 1 and 2 appear below..... I have FPV so I can read battery voltage from the ground.

View attachment 13738View attachment 13739

 

[kloner]

the easiest way is to use an Internal resistance reading of ewach cell and determine if shes done or not. I never fly a pack with an uneven or high resistance. Icharger, i think that hyperion both read em.

the usual is 2 years or 200 cycles. Some people claim 500 but the way i fly, 200 is pushing it.

 

[gtranquilla]

Excellent. My Hyperion reads 15 milliohms for all 6 cells.... used to be around 12 milliohms per cell..... Turnigy Nanotech..... roughly 50 recharges so far.

 

[kloner]

in my experience them nanos are the quickest packs on the market to loose IR..... the blue turnigy ones are some of the best...... behind gens ace

 

[DucktileMedia]

I was in a crunch and bought some semi used gens ace lipos. The IR is around 10-15/cell. I can balance charge them to 4.2/cell and they seem to hold which is good. But Im not sure I like the high IR reading. I also impulsively bought some Zippy lipos the guy said they have less than 10 flights and the IR is around 10/cell. Are these all shot or do some lipos just start higher? I've always just flown a pack until they cant hold an even charge of less than .2-.3v per cell. So in other words if one cell reads 4.17 I get a little worried if I cant balance it out.

On another note, specifically the icharger 206b, when you are in the special modes and looking at the IR, if you go a page over it says a bunch of numbers that look to be per cell voltages. They are listed as 4.12-4.18v/cell. I got worried and put the lipo through another balance charge cycle just for half a minute to see what the voltage reading was. They were 4.2. So now I am very confused as the reading on the charge cycle says they are all at 4.2 yet this other page is saying 4.15-ish. Any ideas? I wish I had the icharger before but I am new to it.

edit: so, in reading the online manual I see that the reading I am referring to was the idle output voltage. Should the charge voltage and idle output voltage be closer to each other? Usually if I can charge a lipo to 4.2/cell it will read 4.2/cell on an external volt meter. I don't get it.