Fast DC Charging

I don’t think that is the issue as 310FLYR has the same problem at +9 C. I’m having issues as well. Starts charging fine at about 130kW for 5 minutes then goes down to 25-30kW, even when charge state is only 50%. I’ve had this happen on two different DC Fast Charge providers so I’m thinking is something with the truck’s charge system.

Thanks @Voltz. As per my above note this happens even when the truck is at a 50% state of charge. So say I arrive at 47%, after 5 minutrs, I will be at 50% and the truck charge rate will drop down from 130 to only 30 kW.

It was 0 C when this happened the other day. If that’s the charge rates we get at 0 C, then that’s not too good. Where I live it can be that temp in the morning at any point from mid fall to late spring.

As for what the station is displaying. At the electrify I was at it just shows the charge rate. Doesn’t appear to show what the truck is requesting.

R.I.P. said:

0c is very cold for the battery to try to charge. Even 9c is far too cold to take a heavy charge. A Tesla will start preconditioning its battery 15 minutes out even at 70° f. It wants the battery 80°+ for optimal charge rates.

Nobody has been able to demonstrate yet that the Ford is preconditioning appropriately. It is the most likely suspect for slow charge rates at temperatures below 70° f.

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Thanks @R.I.P. for the response. Maybe it is the cold. Just to provide some more information, I had just completed a 1 hour trip.

I’m pretty new to this EV stuff but I would have thought if it was a cold issue, wouldn’t it go pretty quickly to the low charge rate? I wouldn’t have thought it would draw130 kW for 5 minutes before dropping charge rate?
Also I tested and if I stop charging and then restart charging it will go back up to 130kW. Again after 5 minutes charge rate drops.

I am. Thanks again @R.I.P. Will do.

R.I.P. said:

It is a factor of the chemistry of the batteries. In super generic terms, there are electrons that are easy to move, and electrons that are harder to move. The easy ones can be moved quickly with high voltage, but when it gets to the harder electrons things slow down very fast unless the battery is warm. I recommend googling "why cold lithium batteries resist a charge" for some very in-depth white papers on the subject if you are a nerd like me and enjoy reading that type of thing.
🤓

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Follow up question on this. If the battery is only charging fast for the first 5 minutes because some electrons are easier to move and some are harder to move, then why can I get a fast charge rate again by just stopping the charger, then plugging in again for 5 minutes? Effectively I can get a 130 kW charge for 20 minutes by just continuously repeating the above procedure. I have done this successfully and added approx 33% to my battery.

My guess is that the charge controller on the lighting is choosing to charge at a lower rate (30 kW) after 5 minutes for another reason. That has to be either an error, or an attempt to protect the battery.

Thanks @R.I.P. Makes sense to me that it might be a time based thing and understood I probably should avoid doing this and just let the Lightning do it’s thing. When in a time crunch the other day, restarting to get my charge rate up was a bit too tempting. I may inquire with Ford just for curiosity on what they say. I’m sure they’ll make their charging a little smarter as time goes on.