Yes, there seems to be some confusion here.

The Hyperion Sentry and other similar meters calculate the estimated capacity of the battery based on RESTING voltage. That is they estimate mAh from pack voltage. This is not the voltage under load. Depends a lot on battery characteristics, temperature etc and it is only an estimate based on assumptions about voltage vs. capacity curve for the LiPo. I have two excellent quality meters that do this and they give significantly different results.

The Quanum measures the actual current used and integrates the readings over the time for which it has been running. Within the accuracy of the meter it is an exact value for capacity used in mAh. It starts the timer from zero when you plug it in so the reading is for the capacity used in that run.

The 99% figure is probably just meter error and/or the small current the system is using apart from motor load.

John

PS: The capacity vs. voltage methods for estimating end point was extensively discussed earlier in this thread and elsewhere.

My conclusion in the end was that there are people who firmly believe in one method or the other. There are arguments for both and it depends a lot on your flying style and environment, particularly cold weather. IMO neither is absolutely preferred for all situations. At least with the Quanum you can use both.

Is it better then to set the display to show the consumption instead of the remaining capacity?

Whichever you find easiest to understand. They are the same value just presented differently.

Note that you still need to know the CORRECT capacity of the battery (not what the manufacturer printed on the label) to get meaningful results of % capacity used or left.

Originally Posted by sonnydc

Is it better then to set the display to show the consumption instead of the remaining capacity?

Originally Posted by Bill Glover

I disagree. Measuring resting voltage as suggested (not under load) gives a pretty good estimate of percentage charge remaining. What varies based on age (and nature of usage) is the capacity.

Two packs straight off the same charger will show the same voltage (100% charge), regardless of age. Take 10 amps for 5 minutes out of both of them and they may then show different voltages. But that's because one is now further discharged (in percentage terms) than the other.

Put those batteries in the sun for a while, and the voltage will change, but the capacity does not. It is still just an estimate.

Originally Posted by Wintr

Put those batteries in the sun for a while, and the voltage will change

Huh?

Originally Posted by sonnydc

Is it better then to set the display to show the consumption instead of the remaining capacity?

I've been flying the earlier version of the Quanum system for over two years now ...... I would never fly without it on my more exotic(relatively expensive) planes (Hangar 9 and Sebart's) .........

I have the mini screen mounted on my Tx so viewing is easy during flight ..... I view 'Consumption' as a key statistic and set myself a limit of around 3/4 of the capacity used, on landing ....... If I'm flying a 4000 mAh lipo I'll try and make sure I'm down at say 3000) ..... I also keep a key eye on overall voltage(particularily under load) and now and then individual cell voltage to spot any cell dropping off, indicating to me a battery on it's way out, and not for future use ......

What do they say? ..... keep it simple ....

Originally Posted by jj604

Yes, there seems to be some confusion here.

The Hyperion Sentry and other similar meters calculate the estimated capacity of the battery based on RESTING voltage. That is they estimate mAh from pack voltage. This is not the voltage under load. Depends a lot on battery characteristics, temperature etc and it is only an estimate based on assumptions about voltage vs. capacity curve for the LiPo. I have two excellent quality meters that do this and they give significantly different results.

The Quanum measures the actual current used and integrates the readings over the time for which it has been running. Within the accuracy of the meter it is an exact value for capacity used in mAh. It starts the timer from zero when you plug it in so the reading is for the capacity used in that run.

The 99% figure is probably just meter error and/or the small current the system is using apart from motor load.

John

PS: The capacity vs. voltage methods for estimating end point was extensively discussed earlier in this thread and elsewhere.

My conclusion in the end was that there are people who firmly believe in one method or the other. There are arguments for both and it depends a lot on your flying style and environment, particularly cold weather. IMO neither is absolutely preferred for all situations. At least with the Quanum you can use both.

using the quanum for couple of years now, very statisfied about it, but i hope in version 4 they will implement this nice feature.
- showing the state of the Lipo capacity when Lipo is connected and gives you a warning when not > 95% full and not showing 99% in most cases, this is misleading , capacity indication is related to the cell voltage and gives a good indication of a healthy lipo . ( Like the HK cellmeter does)
I dont need to know exactly what is the capacity left, but it gives me a warning i did not use a full loaded Lipo, i can change then the consumed warning level myself or charge the lipo first.

Also a step further it is possible quanum adjust the warning level automatically when calculating the capacity by measuring the cell voltages.

e.g. you have set the lipo capacity to 5000mAh
the consumed capacity alarm is set to 4000Mah , but when lipo is connected first time and current < 1Amp then it does calculate the capacity of the Lipo by measuring the cell voltages and finds it is 70% ( 4,02V per cel) then it wil set the consuming alarm automatically from 4000mAh to 2500mAh

Originally Posted by mrforsyth

Huh?

Like many batteries, if you raise the temperature, the voltage will rise; not a great deal, but enough.

Originally Posted by hobie14

I've been flying the earlier version of the Quanum system for over two years now ...... I would never fly without it on my more exotic(relatively expensive) planes (Hangar 9 and Sebart's) .........

I have the mini screen mounted on my Tx so viewing is easy during flight ..... I view 'Consumption' as a key statistic and set myself a limit of around 3/4 of the capacity used, on landing ....... If I'm flying a 4000 mAh lipo I'll try and make sure I'm down at say 3000) ..... I also keep a key eye on overall voltage(particularily under load) and now and then individual cell voltage to spot any cell dropping off, indicating to me a battery on it's way out, and not for future use ......

What do they say? ..... keep it simple ....

Same here. Goes up in what ever i fly. I still have the first version.....

Originally Posted by jaccies

using the quanum for couple of years now, very statisfied about it, but i hope in version 4 they will implement this nice feature.
- showing the state of the Lipo capacity when Lipo is connected and gives you a warning when not > 95% full and not showing 99% in most cases, this is misleading , capacity indication is related to the cell voltage and gives a good indication of a healthy lipo . ( Like the HK cellmeter does)
I dont need to know exactly what is the capacity left, but it gives me a warning i did not use a full loaded Lipo, i can change then the consumed warning level myself or charge the lipo first.

I totally agree. Now I'm assured that my unit is not faulty. Thanks for confirming this

Originally Posted by Wintr

Like many batteries, if you raise the temperature, the voltage will rise; not a great deal, but enough.

Huh?

It is just a chemical property of the batteries. When they get warmer they also increase in voltage a little bit.

You already know the voltage (related to apparent power) goes DOWN in cold weather, so why is it a surprise the voltage goes up when you warm them. (thus the comment put them in the sun, or maybe in your pocket).

Originally Posted by Wind Junkie

It is just a chemical property of the batteries. When they get warmer they also increase in voltage a little bit.

You already know the voltage (related to apparent power) goes DOWN in cold weather, so why is it a surprise the voltage goes up when you warm them. (thus the comment put them in the sun, or maybe in your pocket).

i am talking about a lipo with no load on it.
never noticed voltage goes down in cold weather or voltage increase when you warm them

any example of voltage increase, decrease values to temperature ?

or is it a temperature problem with your voltage measuring device

Originally Posted by mrforsyth

Huh?

Mark you are also suprised?, is this also new for you

Originally Posted by jaccies

never noticed voltage goes down in cold weather or voltage increase when you warm them.

Haven't tested this, but there is a rule that Lipos shouldn't be charged in low temperatures, as voltage measured by the charger will be lower than normal, and they will be overcharged.
FMA chargers have a low temperature feature that will terminate charge at 4.1V to avoid damage.

Fred