# Has anyone developed a reliable deep space battery that doesn't need to be kept warm?

Has anyone developed a reliable battery for use in cold deep space applications? Something that doesn't need to be kept warm?

For exampe lithium batteries certainly has its constraints due to the temps but does Graphene or SS type applications help solve this issue?

I understand a company in China Guangzhou Auto Group has been working with China Carbon on the Graphene high density ultra cold applications and is Quantum Scape working on a SS version?

Thank you for photo Credit to: photographer, Adam Makarenko adammakarenko.com/photography image is Ice Probe I.

• "cool" question!
– uhoh
Mar 15, 2021 at 1:19
• Couldn't you just insulate the battery and use some of its power to keep it warm if needed? You'll have to shield it from space radiation anyhow, why not shield it from cold temperatures?
– user39728
Mar 15, 2021 at 1:27
• Batteries aren't the only thing that's temperature sensitive, or even the most sensitive thing on a probe. The hydrazine that's commonly used as a monopropellant will freeze a bit above the freezing point of water, for example. And what does "SS" refer to? Mar 15, 2021 at 2:46
• Most solid-state electronic items (CPU, transistors, etc) are quite temperature-sensitive as well, so you don't save a lot by heating everything except the battery. Mar 15, 2021 at 13:30

A Radioisotope Thermoelectric Generator (sometimes referred to as a nuclear battery) is probably your best best: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

Although it gets warm it doesn't need to be "kept warm" as it heats itself from nuclear processes within the radioactive materials sealed inside it and it produces electricity. The down side is it only produces a small amount of electricity, but better than nothing and you might be able to make use of the waste heat it produces.

• Sorry, but -1 because a generator is not a battery. Mars rovers would be in a bad way if you took their batteries away and told them to run on their RTGs, because one function of a batter is to "buffer" energy from an RTG and then provide a higher level of power during "peak demand". If you embedded smaller radioisotope heat sources within conventional batteries you could keep them warm, but the question specifically asks for "a reliable deep space battery that doesn't need to be kept warm". I don't think there's even an unreliable one yet.
– uhoh
Mar 16, 2021 at 10:32
• Thank you all for your comments, we have more to research but are working on something very exciting for a unique interplanetary communications platform. You are all very much appreciated and thanks again to all. Mar 16, 2021 at 18:07

Electrochemical batteries that are independent of temperature are impossible. There have been different designs for high, medium and low temperatures, but for each design there is a certain operating temperature range. All chemical reactions are faster at higher temperature and slower at lower temperature.

If it is too hot for the battery, lifetime of the battery will be shorter. If it is too cold for the battery, voltage and possible maximal current will be too low.

A battery designed for very low temperature should be kept cold before launch. It will be too hot for the battery at the first part of the flight into deep space.