Lipo auto power off

[MikeB]

I'd guess at a G.T.POWER Digital Battery Capacity Checker (upside down ion the picture!).

Mike.

[Billthetug]

The one shown above

[Billthetug]

As above

[Daedalus66]

That sort of meter doesn't directly measure capacity. It's just a digital voltmeter with an algorithm to convert voltage to remaining capacity. Unfortunately, the very flat voltage discharge curve of LiFe batteries makes this a very rough indicator.
http://www.rcmart.com/power-lipo-tester-p-36098.html

I would be very skeptical about the 35% figure, which is not at all consistent with a reading of 10.0 volts. A number like 80 or 85% would be more like it. Moreover, the recharge data indicate that the battery had about 60% capacity remaining. That would correspond to a voltage reading of 9.9 or 9.8.

Basic conclusion is not to take the readings of cheap meters too seriously (this one costs about $8 on eBay). The transmitter is likely significantly more accurate if properly calibrated. As I suggested earlier, if you don't have an accurate meter, a reasonable approximation can be achieved by assuming that the voltage after half an hour or so of discharge is 9.9.

By the way, once the voltage drops below about 9.6, the discharge curve gradually becomes steeper and voltage becomes a better indicator of remaining capacity.

[Billthetug]

The one in the picture above

[Billthetug]

Cheap and cheerful but at least I don't have to try and stick test meeter probes into small plugs and risk shorting and yes cheep means not very accurate but it will do for in the field
Bill

[Kilrah]

Yep, no problem with that. Just ignore the % indication and stick to the voltages

[Billthetug]

Just out of interest I managed to get 9hrs out of the life04 before the alarm went off so one happy chappy.

[Daedalus66]

Just out of interest I managed to get 9hrs out of the life04 before the alarm went off so one happy chappy.

That sounds about right. Nine hours should be enough for a decent amount of flying!

We seem to get two or three years of use out of the HK LiFe batteries. I always have a spare, not only as a backup if I forget to charge but also in case I accidentally run the transmitter battery down all the way. The batteries go in and out of stock, so are not always available.

By the way, I've found that the batteries can survive a single discharge to zero and still be revived (using the NiMH cycle for about 30 minutes at about 500 mA to get the voltage back up to the range where the LiFe cycle works - be careful!). A second full discharge, though, results in swelling to the point where the battery is no longer usable.

[Billthetug]

Yes I have a spare just in case
Now a question I have been setting up the throttle cut safety switch whilst I wait for my hk-450 kit to arrive, I have it set but can you tell me what the difference is with thr and !thr please.
Cheers


Sent from my iPad using Tapatalk

[Daedalus66]

THR means the throttle switch ON. !THR means the throttle switch NOT ON (for a two position switch that obviously means OFF but for 3 position it could be either of the other two positions).