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Post by kris on Aug 10, 2023 19:14:27 GMT
I see bimblesolar are selling lto batteries that they claim are good for 30,000 cycles. I’ve never heard of claims of this many cycles before, I’ve heard of claims of 6000-10,000. www.bimblesolar.com/
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Post by Telemachus on Aug 10, 2023 21:20:23 GMT
Depends on how you define a cycle.
LTO batteries don’t fit well into a 12v system, 6 cells is too many and 5 is too few. Unlike LiFePO4 they have a big spread of voltage with SoC.
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Post by kris on Aug 10, 2023 21:21:35 GMT
Did somebody say something?
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Post by Telemachus on Aug 10, 2023 21:29:00 GMT
Did somebody say something? Do you have a poor internet connection?
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Post by Aloysius on Aug 10, 2023 21:48:50 GMT
Depends on how you define a cycle. LTO batteries don’t fit well into a 12v system, 6 cells is too many and 5 is too few. Unlike LiFePO4 they have a big spread of voltage with SoC. Although that device is 48v, shirley a 12v step unit would solve any such issues.
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Post by on Aug 11, 2023 5:16:42 GMT
I charge my LTO batteries (6s) to 15.2 volts with the solar panels. This is around 85%. The Prosine inverter is happy up to 15.8v.
Nothing bad happens. You can charge them to a lower voltage than that as well you just lose a bit of capacity.
They do advertise good cycle life and can take ten times their capacity as a charge or discharge rate happily. Durable and very safe batteries. Not light but that doesn't matter much in boats.
I would not pay the bimble prices but mine were around the price of good AGM batteries so a different story.
LTO is a very good chemistry for boats.
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Post by kris on Aug 11, 2023 5:47:51 GMT
I charge my LTO batteries (6s) to 15.2 volts with the solar panels. This is around 85%. The Prosine inverter is happy up to 15.8v. Nothing bad happens. You can charge them to a lower voltage than that as well you just lose a bit of capacity. They do advertise good cycle life and can take ten times their capacity as a charge or discharge rate happily. Durable and very safe batteries. Not light but that doesn't matter much in boats. I would not pay the bimble prices but mine were around the price of good AGM batteries so a different story. LTO is a very good chemistry for boats. I was just wondering about the bimble claim of 30,000 cycles. Even for lto I’d only heard of 6000-10,000 claims before.
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Post by on Aug 11, 2023 7:33:52 GMT
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Post by kris on Aug 11, 2023 7:37:02 GMT
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Post by kris on Aug 11, 2023 7:40:52 GMT
I just find it interesting, they could probably claim as many cycles as they like.
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Post by on Aug 11, 2023 7:43:18 GMT
Pleasant little video.
Not sure what Bimble put in their boxes but quite likely to be the Yilong cylinders. Could be something else as there are several manufacturers. Mine are Toshiba or possibly Microvast.
"with careful use you can easily exceed 30 thousand cycles".
Now I suppose careful means 1c charge / discharge. For a test you could charge at 40a for an hour then discharge 40a for an hour. So you would need 60,000 hours which is about 7 yars continuous testing.
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Post by Telemachus on Aug 11, 2023 7:52:49 GMT
It’s all a bit academic. Maybe in a laboratory under ideal conditions of optimum temperature, no vibration, perfect charge profile straight into perfect discharge profile straight into perfect charge profile etc, 30,000 cycles might be achievable. But real world use where the environment is not ideal, likely the cycle life will be less. In particular there will be an element of calendar aging so for batteries cycled once per day or less, calendar aging may overtake cycle aging as the primary cause of loss of capacity.
Our Li batteries will probably die from aging before they die from cycle life. They are a bit oversized so so far, after being in for 2 years, the total discharge is 29,500 Ah which corresponds to about 50 full cycles to 100% DoD. Based on the expected cycle life of perhaps 3000 cycles, that would give a life of 120 years. But I suspect calendar aging will kill them much sooner.
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Post by kris on Aug 11, 2023 7:55:53 GMT
Pleasant little video. Not sure what Bimble put in their boxes but quite likely to be the Yilong cylinders. Could be something else as there are several manufacturers. Mine are Toshiba or possibly Microvast. "with careful use you can easily exceed 30 thousand cycles". Now I suppose careful means 1c charge / discharge. For a test you could charge at 40a for an hour then discharge 40a for an hour. So you would need 60,000 hours which is about 7 yars continuous testing. This is probably where the 30,000 cycles claim comes from.
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Post by on Aug 11, 2023 8:05:23 GMT
It is an interesting claim.
These batteries have been in electric buses in China for quite a long time so there may be proven performance characteristics.
It might be an assumption. They could have tested at 10C and got say 10,000 cycles and extrapolated from that.
Careful use will be 1C I am pretty sure. I got mine from an electric car man who knows his shit and he reckoned 1C for charge and discharge was the most sensible thing to do with them even though they can do a lot more.
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Post by kris on Aug 11, 2023 8:09:47 GMT
It is an interesting claim. These batteries have been in electric buses in China for quite a long time so there may be proven performance characteristics. It might be an assumption. They could have tested at 10C and got say 10,000 cycles and extrapolated from that. Careful use will be 1C I am pretty sure. I got mine from an electric car man who knows his shit and he reckoned 1C for charge and discharge was the most sensible thing to do with them even though they can do a lot more. Oh you didn’t get them from James then.
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