How do the LiFePO4 cells in a Bluetti AC180 take such a high current charge?

[IGBT]

I have been playing with my Prime Day Bluetti AC180 and noticed it can charge at near 1400 watts.

It has (I think), about a 29V 40AH LiFePO4 pack inside. Charging at 1400 watts, that is 47 amps going into these cells.

How bad is it to charge at that rate vs the standard rate of about 800 watts or the silent rate which is I think 350 watts? As in
reduced lifetime?

 

[Mattb4]

Looking it up it shows up to 1440W for rapid charging in about an hour. Yeah that is a high rate of charge and would make me suspect that it reduces overall battery lifetime. However I do notice wording to the effect that it might limit rapid charge to 80% of full charge.*


* If you can discharge at a high rate without damaging the battery a high rate of charge should not damage it either. Or at least that is my initial thinking.

 

[plympton]

My AC300 charges to 90% on solar at full rate (~2000w my panels will generate), and then go to 1000w. If there's a demand, it'll use more solar. Once it hits 100%, it will cycle 99-100% as it is in UPS mode, so it's essentially always on battery.

You can see it in action here - at 90%, it'll go down to the 1000w, and then at some point my fridge goes on defrost cycle, and the 99% behavior. I would assume the AC180 has a similar, but probably not the same, charging profile.

 

[plympton]

Pondering - there's probably some sweet spot in charging. Fast, and it could degrade the batteries*, slow and it might be less efficient - the charging (inverter) overhead might be constant, so if you charge longer you lose more of that power per time.

* maybe - NMC, yes, LFP? Dunno - did a bunch of searches and it was mostly around Model 3's, and all anecdotal

 

[IGBT]

Pondering - there's probably some sweet spot in charging. Fast, and it could degrade the batteries*, slow and it might be less efficient - the charging (inverter) overhead might be constant, so if you charge longer you lose more of that power per time.

* maybe - NMC, yes, LFP? Dunno - did a bunch of searches and it was mostly around Model 3's, and all anecdotal

Before I bought this one I watched this teardown video. It is a UK version of the AC180 but it shows the build quality and the cells. The guy didn't know an extreme amount about the cells but I think they are LiFePO4 just based on the weight. NMC would be lighter and have a 500 cycle life.

One of the comments in the video: "Should be 10S6P as there are 60 cells rather than 30 cells. It's 2 layers of 5x6 as each cell is 70mm tall for a 32700. Also, 6P * 6Ah/cell * 32V = 1152Wh."