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Discussion Starter · #1 ·
I'm not sure if I'm using the right term here but I've noticed something with the charging rate. The amount of time spent in the slow charging phase varies considerably by the amount of time the 4xe has been charging. If charging starts from depleted it seems ramp down and spend about 30 minutes gradually reducing the charge.

If the charge initiates when there is around 80% battery the 4xe will pull 7.6 kWh up to the last minute or two of charging.

Originally I thought it would always reduce the charge rate when it was over 95%

This has me wondering if we should be charging after frequent short trips.
 

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Discussion Starter · #2 ·
I figured pictures would help. The top one is from a more depleted state (10%). The curve usually has the same profile each session but can vary in time slope. The spikes and valley are always there.

The bottom one was a charge started from 80%. Those shorter charges never seem to have the slow phase. I used to think that initiated at 90-95% charge, but that doesn't seem to be the case.

Purple Rectangle Slope Violet Line


Rectangle Font Parallel Tints and shades Slope
 

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This may be related to battery temperature. Shorter charges don't generate the heat, so no ramp-down at the end. Or there may be an occasional battery conditioning cycle which you see during a long charging time, but not an isolated quick charge. Is the short charge always consistent over multiple times?

I caught mine running some sort of pump (cooling I assumed, but may have been a conditioning cycle) several hours after a short charge was completed. That may be what is happening toward the end of that long charge.
 

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Discussion Starter · #4 ·
I actually caught a short charge doing it now. So my initial assumption was a little off.

Getting to see the data just makes me super curious: the shape of the curve, the time spent in that phase, the two spikes up and one down, etc.
 

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Yeah, guessing something thermal. I think our batteries also don't charge to 100% like, say, a Tesla - so there's probably some cleverness involved with stopping the charge when you put a lot of energy in to make sure it doesn't go too far. Maybe - just a guess. Normally, lithium chargers always do the ramp-down at the end as they switch to constant voltage, from what I understand about them.
 
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