Mysteries of using electricity in space

[GungaDin]

Up until now I have paid no attention to my electrical systems.  I'm at the point now where I'm trying to transmit science data back home and I keep finding that I have no damn electrical charge left.  I tried installing a rechargeable battery in a storage bay but that didn't help.  I'm guessing that I will need a solar panel but I'm surprised that I have no charge left if I've only been off the pad for a few minutes.  Thanks for any help comrades.

 

 

[VoidSquid]

Товарищ!

Ты отключили «Требовать завершения» для антенны?

[bewing]

Probe cores only start with about 5 EC. They use .02 per second -- so yes, the electricity stored in a core only lasts about 15 minutes, typically. SAS/reaction wheels use a lot. So you have to learn to be efficient about reorienting your rocket. Transmissions of any sort use a tremendous amount of EC. You have to memorize in advance that a SciJr will use 125EC to transmit a report, for example, and plan for it in advance. Researching in a Lab will use 5 EC per second, which is quite big compared to what a solar panel can produce. And the big drills can use almost 30 EC per second - similarly with the big converter. And transmitting a survey from orbit can easily cost 1000 EC depending on the number of biomes. You have to have enough batteries on your craft to handle all of these things that you plan to do, and then you have to have some solar panels to charge everything back up afterwards.

[GungaDin]

I guess I could start with multiple batteries and do my transmission as soon as I get to orbit.  Is there a special place to hook up batteries or are they live as long as I store them somewhere?

2 hours ago, VoidSquid said:

Товарищ!

Ты отключили «Требовать завершения» для антенны?

Нет, сэр. Что это делает?

[VoidSquid]

Позволяет передавать данные, даже без достаточной электроэнергии (частичная передача, с потерями, не сильно, хотя).

 

Edited October 23, 2019 by VoidSquid

[Fierce Wolf]

3 hours ago, GungaDin said:

I'm guessing that I will need a solar panel

Why don't you use solar panels? they are super useful

[Zhetaan]

2 hours ago, GungaDin said:

I guess I could start with multiple batteries and do my transmission as soon as I get to orbit.  Is there a special place to hook up batteries or are they live as long as I store them somewhere?

Batteries can be attached anywhere.  Some are radially-attached and can go anywhere, and there are two sized at 1.25m and 2.50m for in-line placement.  The radial ones are best placed inside a service bay, fairing, or cargo bay until you get out of the atmosphere, because they cause drag otherwise and are not very heat-resistant.

Also, there are more generators than just solar panels.  Many of the engines, for example, have 'alternators' (a real device but not used on real rockets) to generate power during launch when the solar panels are stowed or hidden behind fairings.  If you haven't noticed a loss of power during ascent, then it's likely that your engine has been keeping your power levels full during launch without you noticing.

If you're not planning on using the vessel again, then you don't need solar panels; you can send enough batteries to complete the mission and then abandon the vessel to space.  If you do plan to use the vessel again, then you only need enough batteries to send your most demanding (in terms of electric charge) report, and only enough solar panel to cover your average consumption plus a bit for recharging.  If you're less patient and want to send more reports, then add more batteries.  If you're even less patient than that and want to recharge quickly, send more solar panels.  Just remember that each battery and panel you add beyond what you need adds parasitic mass, which requires larger and larger rockets to lift.

As a secondary recommendation, note that batteries all have the same charge-mass ratio, meaning that no battery is more mass-efficient than any other for the amount of charge that it contains.  Solar panels are another matter; the OX-4L and OX-4W are the best, and the Gigantor is next.

[Vanamonde]

Please remember to post in English when you're not in the other-language parts of the forum, guys. 

[GungaDin]

3 hours ago, Fierce Wolf said:

Why don't you use solar panels? they are super useful

I'm in a career game and haven't earned the science yet.

[AHHans]

On 10/23/2019 at 4:40 PM, GungaDin said:

Up until now I have paid no attention to my electrical systems.  I'm at the point now where I'm trying to transmit science data back home and I keep finding that I have no damn electrical charge left.

Well, I guess you haven't done anything that uses significant amounts of electricity before, but transmitting science through an antenna can use large amounts of ECs.

18 hours ago, GungaDin said:

I'm in a career game and haven't earned the science yet.

In this case I would recommend to not transmit the science but collect it with a Kerbal and store it in the capsule until you return. Bringing enough batteries to last the mission and/or recharging them with your engines is IMHO not worth the effort.

On 10/23/2019 at 4:47 PM, VoidSquid said:

Ты отключили «Требовать завершения» для антенны?

Well, that doesn't help him much if he doesn't have anything that generates electricity to recharge the batteries... (Google Translate rules.)

The "allow partial" option of the antennas means that if you run out of ECs while transmitting science then the transmission isn't completely canceled but continues when some more ECs become available until all data is transmitted. This is not a solution if you don't have ways to generate ECs, but it is a solution if you don't have enough battery capacity to transmit everything in one go. There are two side effects: one is that while the transmission is ongoing all the electricity will be soaked up by the antenna, leaving you none to do anything else. The other is - as already mentioned - that you loose a fraction of the science. The first doesn't matter much if you are in a stable situation (in orbit, landed, or on a long-ish transfer) and can just wait and recharge your batteries before you need them again. The second can be redeemed by re-doing the experiment and re-transmitting it as often as needed to get all the science.

[Xd the great]

On 10/24/2019 at 6:20 AM, GungaDin said:

I'm in a career game and haven't earned the science yet.

You seem like you are running out EC on the pad.

Use launch clamps (If you have unlocked them).

Another way is to use fuel cells. They consume fuel and strand my kerbals, but who cares?

[Linkageless]

Some experiments produce more data, so require more battery charge to transmit.

As suggested, be sure that at least your choice of engine can generate power for you and ideally carry enough battery to cover longer transmissions.

Be aware that some antennas are more efficient so will use less battery to transmit a given experiment.

If all else fails, you can set "allow partial" on the antenna, and run your engine (assuming it is a model that has an alternator) to generate power while you transmit on your way to your next destination.