Which do you use to calculate 80% usage?

[PeteStewardson]

OK so I have a battery checker, when I've taken the lipos off the heli it shows a % of charge. But when I charge on the PL8 I get the total Mah put back in. If I take the battery off the heli and leave it a bit the fusion checker might say 23% left for example, but when I charge the numbers might indicate I have 45% left.

So which is right, and which do you use as the guide to know how long you can fly for?

[acidla]

Hi mate,

I have the same voltage checker. At 10-15% i was close at 80% of the used capacity.

I now use telemetry with mAh counter..

[Grumpy]

Short of telemetry (which i agree is the ultimate solution) I just like to keep it simple and check cell voltage. If the battery has in the range 3.7 to 3.75V then I'm good, if lower or higher adjust flight time (especially lower, obviously). I dont worry too much about % remaining estimates or mAh I put back in, at the end of the day it's the voltage falling too low that does the damage.

[scallybert]

The PL8 & PL6 have a means of generating 'fuel tables' for each type of pack. These tables relate the %age fuel level to the pack voltage.

if you calculate these, the fuel levels might be accurate for that pack type.

The battery checkers don't have anything like this. Which suggests they are a rough guess.

[ghost2212]

I wouldn't even trust the battery capacity in the first place, I would aim to run the batteries down to a resting voltage after a good few minutes of between 3.75v and 3.8v per cell.

[helijohn]

Because they have such a good rep I only trust the icharger.

[askeys_heli_madness]

OK so I have a battery checker, when I've taken the lipos off the heli it shows a % of charge. But when I charge on the PL8 I get the total Mah put back in. If I take the battery off the heli and leave it a bit the fusion checker might say 23% left for example, but when I charge the numbers might indicate I have 45% left.

So which is right, and which do you use as the guide to know how long you can fly for?

My thoughts are that the battery checker will read down to 0%, however this could well be the 20% voltage of the pack, hence the difference you are noting.

For instance your mobile has a lipo in it, but when it is allegedly at 0% charge i.e flat I bet that is still at the 20% level.

Therefore as others have said, look at the voltage as an indicator, keep it above 3.70, and note the capacity. Compare this with the mAh put back in and it may be that 0% on the battery checker is actually the 20% capacity of the battery. If that makes sense?

[Grumpy]

Because they have such a good rep I only trust the icharger.

A bit cumbersome to cart down to the field just to check battery remaining voltage/capacity though? Personally if all you want is a remaining voltage check a little cell checker popped in the pocket is the way to go. They are not intended to be precision measuring instruments but they are more than accurate enough for the purpose intended.

Unless of course you have a field charging rig, then fine, check voltage with that if you like.

[helijohn]

A bit cumbersome to cart down to the field just to check battery remaining voltage/capacity though?

It's not much bigger than a pack of 20 fags so takes no space at all. I have a fag lighter socket in the back of the motor so it's really convenient.

[Varelco]

I use a fusion battery checker, which ive always found to match up to what my icharger says when I recharge. Im interested in the rest voltage, not the stated capacity.

[Delarado]

For instance your mobile has a lipo in it, but when it is allegedly at 0% charge i.e flat I bet that is still at the 20% level.

iPhones have Li-ion. Not sure about others.