Very Interesting Tesla Battery Degradation Data
- Thread starter robby
- Start date
ScrotusGobbleBottom
Solar Enthusiast
Nice
Lt.Dan
Solar Wizard
I watched this the other day, and it gave me good hope that these will probably last longer than advertised.
Bluedog225
Texas
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- Nov 18, 2019
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I wonder if there is any warranty on the battery capacity? At least in terms of deviation from the median.
Some of those batteries were real dogs. Be a shame to get a dud with no recourse.
Some of those batteries were real dogs. Be a shame to get a dud with no recourse.
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OffGridInTheCity
Solar Wizard
I run a large 18650 powerwall at 121kwh. Thus, I'm very interested in how long my powerwall will be effective and even more interested in what 'failure' will look like.
But I'm not seeing any way to relate 50K / 100K miles to solar powerwalks. What do you folks think - extrapolate energy consumed per mile from the EV batteries and relate that to energy consumed from the powerwall by the inverters?
Let's try that.....
100K miles at 0.346kwh/mile ( https://ecocostsavings.com/average-electric-car-kwh-per-mile/ ) = 34,600kwh from an EV battery for 100K miles and 6-10% degradation. So far my inverters have consumed ~85,000kwh from the powerwall over 1,957 cycles. That's 2.46 times the 100K energy - so I should see 2.5 times the degradation? - e.g. 6% * 2.5 = 15% degradation??
Don't believe I'm seeing that much degradation but I didn't start with all 9 batteries in the powerwall at once. This is the powerwall makeup over the 85,000kwh consumed to date. Lifetime average of 35.8% DOD.
Perhaps the newer batteries in parallel with battery #1 are propping it up and hiding 15% degradation to battery #1 so it's more like 4% overall spread among all 9 batteries in parallel in proportion to their age/cycles.
I am tracking ah/v of energy provided during 0 PV times - e.g. straight battery -> inverter. This is not apples to apples from year to year because of the new batteries added but soon I'll be 'static' (no more batteries) and I'm hoping that ah/v will eventually give a peek into degradation over the next 5-10 years.
But I'm not seeing any way to relate 50K / 100K miles to solar powerwalks. What do you folks think - extrapolate energy consumed per mile from the EV batteries and relate that to energy consumed from the powerwall by the inverters?
Let's try that.....
100K miles at 0.346kwh/mile ( https://ecocostsavings.com/average-electric-car-kwh-per-mile/ ) = 34,600kwh from an EV battery for 100K miles and 6-10% degradation. So far my inverters have consumed ~85,000kwh from the powerwall over 1,957 cycles. That's 2.46 times the 100K energy - so I should see 2.5 times the degradation? - e.g. 6% * 2.5 = 15% degradation??
Don't believe I'm seeing that much degradation but I didn't start with all 9 batteries in the powerwall at once. This is the powerwall makeup over the 85,000kwh consumed to date. Lifetime average of 35.8% DOD.
Perhaps the newer batteries in parallel with battery #1 are propping it up and hiding 15% degradation to battery #1 so it's more like 4% overall spread among all 9 batteries in parallel in proportion to their age/cycles.
I am tracking ah/v of energy provided during 0 PV times - e.g. straight battery -> inverter. This is not apples to apples from year to year because of the new batteries added but soon I'll be 'static' (no more batteries) and I'm hoping that ah/v will eventually give a peek into degradation over the next 5-10 years.
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Lt.Dan
Solar Wizard
I have heard of them warrantying them if they have a specific amount of degradation in a specific time frame/miles driven. But I don't remember. I want to say 20% degradation before the warranty runs out, which for my specific Model 3 is 8 years or 120,000 miles, for the battery warranty.
robby
Photon Vampire
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