3am DC Fast charging

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justanotherdrunk

Well-known member
Joined
Feb 19, 2015
Messages
265
Location
Silicon Valley
My solution to avoid the crowds.

:lol:

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;)
 
I don't find I get anywhere near that amount of power in 30 minutes using the ABB quick charger near me -- I believe it's the same 50kw one. In 30 minutes yesterday (on a very warm evening) it delivered only 5.5kwh when charging from about 20% SOC. Does the charge rate have anything to do with temperature? If not is it likely a problem with my car charger or with the DCFC charging unit itself?
 
The charge rate very definitely has a relationship to the battery temperatures - the hotter it is, the slower things will be. DC-fast charging develops a lot of heat, and if things are already warm, the cooling system will work full blast, but if it can't keep things in check, will slow the charging rate to keep from damaging the batteries. Also, the DC-power supply itself may restrict power if it is sitting in the hot sun, and it has cooling problems of its own. Keep in mind that is one HUGE power supply, and they do generate a lot of heat. Whether it was recently used could also be an issue.

FWIW, the battery charger for my electric drill won't charge the battery at all if it is too hot, the i3 is doing the same thing.
 
imyrans said:
I don't find I get anywhere near that amount of power in 30 minutes using the ABB quick charger near me -- I believe it's the same 50kw one. In 30 minutes yesterday (on a very warm evening) it delivered only 5.5kwh when charging from about 20% SOC. Does the charge rate have anything to do with temperature? If not is it likely a problem with my car charger or with the DCFC charging unit itself?

Slight reductions in charging speed (for example, to 40kW) can be temperature related, but if you're seeing ~11kW at under 50% SoC then there's likely an issue with the machine.
 
Some of the machines are scalable, IOW, while they may look the same on the outside, they may have a different number of modules inside, and may not be able to provide the full output of others. Plus, that scalability can also mean (in a well-designed system), that if one power supply failed, the others could still provide power, but at a lower level without deadlining the whole thing.
 
jadnashuanh said:
Plus, that scalability can also mean (in a well-designed system), that if one power supply failed, the others could still provide power, but at a lower level without deadlining the whole thing.

That's usually what causes rates this low on 50kW units.
 
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