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Dual chargers

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For anything over 40 amps, the primary charger will ramp up to 50% of the setting, then the secondary charger will turn on and contribute the other 50%. They are both managed together by the BMS and charging logic.
 
Shame they don't split the load below. I've been hauling around a 2nd charger for 28,000 miles and think I've leveraged it once. maybe twice. mostly at the SC after repairs, so I can charge enough to get home.
 
For anything over 40 amps, the primary charger will ramp up to 50% of the setting, then the secondary charger will turn on and contribute the other 50%. They are both managed together by the BMS and charging logic.

Which means if you have dual chargers and you're trying to minimize wear and tear, charge at 41A. Personally I charge at 70A regularly, and 80A when my SOC is below 30 miles.
 
I found out something interesting a few days ago when I was discussing the dual charger option with my local service manager. The second charger is essentially a slave. It does not add any high availability or redundancy to the car's charger capabilities. In other words, if the primary (standard) charger were to fail for some reason, the second charger is not going to take over for the failed primary charger. So it does not add any redundancy to the overall charging system.

That said, I was told that Model S cars with the dual chargers can indeed have a failure in the second charger but the Primary charger will work with a failed second charger. I did not ask if the Model S senses or "knows" that the second charger is failed. I suspect you would have to exercise it with a charge of over 40 Amps?
 
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I found out something interesting a few days ago when I was discussing the dual charger option with my local service manager. The second charger is essentially a slave. It does not add any high availability or redundancy to the car's charger capabilities. In other words, if the primary (standard) charger were to fail for some reason, the second charger is not going to take over for the failed primary charger. So it does not add any redundancy to the overall charging system.

That said, I was told that Model S cars with the dual chargers can indeed have a failure in the second charger but the Primary charger will work with a failed second charger. I did not ask if the Model S senses or "knows" that the second charger is failed. I suspect you would have to exercise it with a charge of over 40 Amps?

What it does do, if you charge at say 42 amps, is only stress each charger at 21 amps on a daily basis. It seems to me that's likely to make both chargers, which are a high wear part, and require liquid cooling, last longer. That's just my guess though.
 
What it does do, if you charge at say 42 amps, is only stress each charger at 21 amps on a daily basis. It seems to me that's likely to make both chargers, which are a high wear part, and require liquid cooling, last longer. That's just my guess though.

Canuck you are right about that. I have a HPWC installed and will probably add the second charger and a center console after I have the S for a short while. Once I get the second charger installed I will always charge at about 50 or so amps set at the car with the HPWC set to go to 80 (if needed).

Does anyone know if a failed second charger sends a notification to Tesla via a log entry or the owner via a displayed error message?
 
Canuck you are right about that. I have a HPWC installed and will probably add the second charger and a center console after I have the S for a short while. Once I get the second charger installed I will always charge at about 50 or so amps set at the car with the HPWC set to go to 80 (if needed).

Does anyone know if a failed second charger sends a notification to Tesla via a log entry or the owner via a displayed error message?

There is no notification to the owner. If it fails, the first way you'll know is your normally 79-80A HPWC charging will max out at 39-40A or so... Assuming you didn't set your MS to charge at a max of 40A, Tesla can then isolate it pretty closely via the logs as to if there is an issue with the 2nd charger or not. IMHO in the scheme of things, this isn't a huge concern as you will still be able to charge if a problem with the 2nd charger crops up -- just not as fast -- until resolution.