Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,056
The "Battery FAQ" has graphs for lead-acid cycle live vs. DoD, compared to lithium capacity vs. number of cycles.
That's an apples vs. oranges comparison.
I've heard that the cycles quoted for lead-acid are not same DoD of original capacity, but DoD of remaining capacity.
What I'd like to see are cycles vs. DoD for both chemistries, and remaining capacity vs. cycles for both.
As for that being a curve for lead-acid, I note that it shows 1300 cycles to 70% DoD vs. 3000 cycles to 35% DoD.
Compare 70% DoD is twice the Wh or 35%, so compare 3000/2 = 1500 with 1300, you get 15% more total lifetime Wh from the battery at the more shallow 35% DoD.
The graph would be a curve even if there was no penalty for deeper cycling.
That's an apples vs. oranges comparison.
I've heard that the cycles quoted for lead-acid are not same DoD of original capacity, but DoD of remaining capacity.
What I'd like to see are cycles vs. DoD for both chemistries, and remaining capacity vs. cycles for both.
Battery FAQ
If you have a battery question and it's not a "beginner" question please try one of the battery boards. Batteries play an important role in solar PV systems providing power while the sun is down or during peak demand hours with excess grid charges. During the day solar energy is converted by...
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As for that being a curve for lead-acid, I note that it shows 1300 cycles to 70% DoD vs. 3000 cycles to 35% DoD.
Compare 70% DoD is twice the Wh or 35%, so compare 3000/2 = 1500 with 1300, you get 15% more total lifetime Wh from the battery at the more shallow 35% DoD.
The graph would be a curve even if there was no penalty for deeper cycling.