Hi all
new to this but very well enthousist about the project! Great work, super video's, huge knowledge, ... I like it!
But I also have a lot off questions when thinking about building such a powerwall myself.
One of them is regarding the used cells. In an old facebook post of Peter on HBPowerWall I've red he was looking for irc18650-28a batteries. I got curious and googled around for the datasheet of that cell. Seems that this cell has a 70% DOD lifespan of 300 cycles. Andthat is if these cell are new.
Now, I've got a PV-System and a lot of data regarding power consumption and generation. I can use all that data to import into SMASunnyDesignWeb. On that site I can simulate battery-systems. I'm simulating with these specs:
Lithium
9,8kWh nominal capacity
88% usable capacity
95% roundtrip
It tells me this battery will make 200 cycle each year. When I compare this to the lifespan of a new irc18650-28a cell with the calculated prediction I get depressed.
With new irc18650-28a cells, the DIYpowerwall will last 1.5 years. So how long will it last with used cells?
Am I missing something? It must be, I hope!
Any comments are welcome!
Kind regards, Roel
new to this but very well enthousist about the project! Great work, super video's, huge knowledge, ... I like it!
But I also have a lot off questions when thinking about building such a powerwall myself.
One of them is regarding the used cells. In an old facebook post of Peter on HBPowerWall I've red he was looking for irc18650-28a batteries. I got curious and googled around for the datasheet of that cell. Seems that this cell has a 70% DOD lifespan of 300 cycles. Andthat is if these cell are new.
Now, I've got a PV-System and a lot of data regarding power consumption and generation. I can use all that data to import into SMASunnyDesignWeb. On that site I can simulate battery-systems. I'm simulating with these specs:
Lithium
9,8kWh nominal capacity
88% usable capacity
95% roundtrip
It tells me this battery will make 200 cycle each year. When I compare this to the lifespan of a new irc18650-28a cell with the calculated prediction I get depressed.
With new irc18650-28a cells, the DIYpowerwall will last 1.5 years. So how long will it last with used cells?
Am I missing something? It must be, I hope!
Any comments are welcome!
Kind regards, Roel