mysterious current drain

[DennyC]

I have a manned craft on the way to the moon that has something that is stealing battery charge.

The craft has an empty cockpit, a manned capsule, a materials lab, two goo canisters, and two thermometers. I am not advanced enough in the tech tree to have solar panels, but have two batteries. The batteries, plus the onboard charge of the crew capsules have been enough for previous missions if I am careful an gentle in maneuvering. Without maneuvering, the current drain is normally 0, and the charge state does not change.

However, after completing a midcourse correction, the electrical usage eventually settled at .01, instead of 0, and now the charge continually decreases. All engines are off. Turning the SAS off does not help. Toggling the torque Off does not help. I tried minor maneuvers, but the current still settles to .01 instead of 0.

When I recalled an earlier save of the same mission, the passive current was 0, as expected, but became .01 again after ejecting from Mun orbit.

What has changed to cause the continual slight discharge? On a long mission, it has a troublesome impact, and prevents things like transmitting science. One mission was lost from this problem.

Edited July 13, 2015 by DennyC

[HoloYolo]

Do you have a probe on there?

[UmbralRaptor]

Are the thermometers active? They have a small drain while taking data.

[jkool702]

I've had this issue as well. May be associated with having a probe on board, although I feel power usage should still be zero if you arent using the probe.

One way I've found around this is to manually turn off any batteries you have on board, and turn them back on when you need them.

[Sharpy]

Is SAS turned off? The cockpit and capsule reaction wheels will drain the batteries. Switch them off and see if the problem persists.

(and always remember most engines have alternators to recharge your batteries even without solar).

[annallia]

SAS off? How about capsul lights? Those things drain way more than you would think... And then there are your insturments, thermometers and such will have a small constant drain if they are actively displaying temperature.

[DennyC]

Aha.

I had the display turned on on one thermometer. Turning it off fixed the current drain.

That seems to have been the problem, although I don't remember using the thermometer the first time I noticed it.

Thanks for your help.

[Snark]

Aha.

I had the display turned on on one thermometer. Turning it off fixed the current drain.

That seems to have been the problem, although I don't remember using the thermometer the first time I noticed it.

Congratulations, glad it cleared up!

Just wanted to highlight jkool702's excellent advice, in case it got missed in the thread: it's an excellent fallback plan that provides insurance against any sort of unexpected electricity shortage:

One way I've found around this is to manually turn off any batteries you have on board, and turn them back on when you need them.

^^ This. The fact that you can activate/deactivate batteries, the same way you can do for fuel tanks, is really handy.

A convenient VAB design technique: put one extra battery on your craft somewhere, and disable it (or you could disable the electricity supply on the command pod itself). That's your "reserve"; it's safe and can't be drained by anything until you activate it. If you ever run out of power, just wait until you need it (for maneuvering, landing, etc.) and then enable the battery.

[bonyetty]

Yep sleep mode works a treat. Did for New Horizons and many other RL space craft too.

[Bev7787]

i managed to get my probe to the Mun with no solar panels with that technique. It ran out of power immediately after I orbited