Curiosity has spent 2820 sols on Mars and this answer to About how long will Curiosity last on its nuclear power? points out that its batteries may wear out faster than its RTG.

Question: How are Curiosity's batteries doing after all these years? Have they significantly degraded? If so how does this impact its roving abilities?


  • 1
    $\begingroup$ For Opportunity, before the end of communication (5111 sols), its main battery went through 5000 charging cycles and retained 85% capacity. $\endgroup$
    – Mys_721tx
    Commented Jan 2, 2021 at 0:43
  • $\begingroup$ @Mys_721tx I want one of those in my laptop right now! What? How heavy? Okay, in my backpack at least ;-) $\endgroup$
    – uhoh
    Commented Jan 2, 2021 at 0:46
  • $\begingroup$ @Mys_721tx Please consider posting that as an answer. You can add a sentence in the beginning that it's not about Curiosity, but it's a relevant (and impressive) benchmark since the evolution of rover technology at NASA is incremental. $\endgroup$
    – uhoh
    Commented Jan 2, 2021 at 0:48
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    $\begingroup$ There's a paper from 2017 with detailed graphs on Curiosity's (MSL's) batteries: "The use of lithium-ion batteries for JPL's Mars missions" (The actual paper has a graph with discharge capacity over time, but it's paywalled) $\endgroup$
    – KarlKastor
    Commented Jan 2, 2021 at 1:00
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    $\begingroup$ @uhoh As I said, the paper is called: "The use of lithium-ion batteries for JPL's Mars missions". I linked the presentation of that paper, because the paper itself is paywalled. Figure 10 in the paper is a very nice graph of discharge capacity over time. $\endgroup$
    – KarlKastor
    Commented Jan 2, 2021 at 1:24

1 Answer 1


Although we have no direct report of how Curiosity's batteries are doing, we can use Opportunity's case as a reference as they are similar in many ways.

The Mars Exploration Rovers (MER, Opportunity and Spirit) and the Mars Science Laboratory (MSL, Curiosity) both use lithium ion batteries from Yardney. (1) The MER batteries are rated for at least 400 cycles at 40% depth of discharge. (2)

The MER batteries are designed to operate with 90% of initial capacities after 300 cycles at 50% DoD. (1) By the time Opportunity ceased communication, its batteries went through 5000 cycles and retained 85% capacity. (3) Both exceeded the original design requirements. Given the MSL batteries are designed to operate with two cycles each sol and total of 670 sols, (1) we should except a similar life on Curiosity.

Furthermore, the MSL battery capacity loss is about 1 Ah per 300 sols and the end of life capacity requirement is 59 Ah. (4, 1) A simple extrapolation shows 8100 sols from the initial 86 Ah.


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