Reading the Cellpro 4s

[founder]

Hello:

When I plug my batteries into the Cellpro after a flight, they are down to about 12% or so. Is this too low? I thought I read somewhere that it should not be below 20%. Does the Cellpro consider this so that 0% on the Cellpro indicates that the battery has lost 80% of it's capacity?

Thank you

[outhouse]

i try and keep mine at 20%

someone else said that there not that reliable on that guage and you should just see how many MAH your putting back in.

for me the cellpro 20% is close enough

[founder]

Thanks, outhouse.

In looking at the amount of MAH I am putting back in, I see that one pack has "1.404 Ah added" and another has "1.28 Ah added". How am I to make understand and make use of these figures? What should I be looking for?

[outhouse]

if you have say a 1000 mah pac and you put back 800mah then you hit 20% perfect.

[CompuFoil]

Multiply your batteries MaH rating by .8. That is the most ou should be sucking out of it.
Eric

[founder]

"I see" said the blind man. My packs are 2200mah. The most I should be putting back in the pack then is 1760mah (80%).

As stated earlier, I only had to put 1404mah into one of my packs. I guess this means that 796mah was still left in the pack. 20% of 2200mah is 440mah, so I still had 356mah left to use (796-440).

The Cellpro did indicate that this pack had about ~13% fuel left (286mah). If I would have used that last 13% that Cellpro reported as fuel, the pack would have been left with 510mah (786-286) and still been over 20% (440mah) in the pack. .

I hope I have the right understanding. I did the math for my own edification. If the above is true, then it does appear that the Cellpro does take into account the 80/20 rule of lipo packs. That is, ~0% on the Cellpro = ~20% in the pack.

I am going to test this after discharge and see for sure.

[astroflyer]

The cell pro doesn't take into account any rule about lipos. it reads 0-100 percent fuel left and if it says 20 percent that's what it thinks that pack has left. it's that simple. 20 equals 20.

You can also check the voltage of the cells when you first plug in the pack. somewhere near 3.8 volts per cell is in the area of 20 percent left from what my two cellpros show me. a few seconds after plugging in and the charge starts voltage will jump a little and the percent left also can jump somewhat, easily to 30 percent or more after initially showing 20 percent. so it's not an exact science, just a guide.

look for after flight voltage near 3.8 and that the packs are not overheated and your lipos should last a long time.

[dct]

One more thing most people don't seem to understand .
Every time we use are packs they age! And no longer have the same mah inside of them,,, they are getting older with every flight.. I have many older packs that are 2200 packs and can't last 4 minutes and only put back 1000mah back into them.. Why ? You ask they no longer have the maternal inside of the battery that will hold the mah or volts.. All batteries do this,,and many IMO don't mark there packs with true size of mah. The 80% rule really only works on (( new packs! ))