Lear charger rated at 16 Amps VS Others rated at 40 Amps

kwsmith007 said:

I'm sure this subject has been covered endlessly somewhere but I'm sorry I can't find anything out about this. As I'm sure everyone is aware the Lear/Home Depot equivalent charger is only rated at 16 Amps @ 240 Volts for a charge rate of 3840 Watts. Most other SAE J1772 chargers are rated at either 30 or 40 Amps For a potential charge rate of 7200 or 9600 Watts. Does anyone know definitively if these higher current chargers will charge the Fisker faster? Are there other issues such as cooling or warranty? Is the charging circuit in the car limited to 16 Amps? The Lear charger is such a POS compared with some of the others and it's huge as well.

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The subject is covered at some length in this thread.

My understanding is that the Karma only draws 16 Amps at 220V so the extra current capacity is not really need for the current generation of the car. The car draws only as much as it needs so there is no difference between the Lear charger and other chargers in that respect. The main difference is the additional telematics, network connectivity, and delayed charging capability, plus the aesthetics of the other chargers.

Fabulist said:

The subject is covered at some length in this thread.

My understanding is that the Karma only draws 16 Amps at 220V so the extra current capacity is not really need for the current generation of the car. The car draws only as much as it needs so there is no difference between the Lear charger and other chargers in that respect. The main difference is the additional telematics, network connectivity, and delayed charging capability, plus the aesthetics of the other chargers.

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That, plus, if you plan to get a new—newer than available now—Leaf that can take the higher current, you might want the higher-current charger. (Existing Leafs have the same lower draw as the Karma.)

Interesting... Thanks for the quick response guys. It seems kind of strange that the Fisker uses the A123 Lithium Iron Phosphate cells, who's claim to fame is fast charging that they would limit the charging rate to 16 Amps. That's like .2 C charge rate which is crazy conservative.

kwsmith007 said:

Interesting... Thanks for the quick response guys. It seems kind of strange that the Fisker uses the A123 Lithium Iron Phosphate cells, who's claim to fame is fast charging that they would limit the charging rate to 16 Amps. That's like .2 C charge rate which is crazy conservative.

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The limitation is the cheaper low power ~3.6 kW chargers Nissan and Fisker chose to put in their cars. The Lear/Home Depot "charger" isn't really a charger, but rather a glorified outlet with some relays and safety interlocks. The industry term now is EVSE.

For AC charging, the charger is actually located in the car, where the AC is converted to DC that can be used to charge the batteries.

I believe the largest single phase charger in a production vehicle is still the Tesla Roadster at 16.8 kW (70 Amps). Though I think Renault is soon to offer a car with a 44 kW 3-phase charger in Europe, where 3-phase is more popular. Actually, that's probably the reason Fisker chose a 16 Amp charger. In much of Europe, 16 A is the max that you're allowed to pull on a single phase.

This is slightly off topic but I just installed a Lear/Home Depot charger in the garage. Doug is correct it is only a switched outlet for safety purposes.

It works well but the problem is the coil cord excessive tension and weight (only 2 ft from the car). So much so that I made a strain relief to take the pulling force off of the Fisker plastic charging socket.

I'll be purchasing a 2nd charging unit for the office but it will not have a coil cord output.

fisker579 said:

This is slightly off topic but I just installed a Lear/Home Depot charger in the garage. Doug is correct it is only a switched outlet for safety purposes.

It works well but the problem is the coil cord excessive tension and weight (only 2 ft from the car). So much so that I made a strain relief to take the pulling force off of the Fisker plastic charging socket.

I'll be purchasing a 2nd charging unit for the office but it will not have a coil cord output.

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Yes.. I have the same problem, I park about 30 inches from the charger and the giant heavy cord is a pain. The funny thing is where I'll mount my office charger is about 16 feet from the charge port on the car, so I'm going to take the Fisker charger to my office and get a new non-coil cord charger for home.

A couple of questions: I have the Lear/Fisker charger

1. When not using the charger, is it still sucking electricity? The lights are on
2. When the car is fully charged, does the energy use stop? I.e. is there any rationale to pulling out the charger once the car is charged?
3. How much energy does it use to charge - I want to calculate how much it costs me to charge the car. My local rate is 6 cents/kwh I believe.

Thanks

bigdaddyo811 said:

A couple of questions: I have the Lear/Fisker charger

1. When not using the charger, is it still sucking electricity? The lights are on
2. When the car is fully charged, does the energy use stop? I.e. is there any rationale to pulling out the charger once the car is charged?
3. How much energy does it use to charge - I want to calculate how much it costs me to charge the car. My local rate is 6 cents/kwh I believe.

Thanks

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BigDaddy:

1) The status LEDs draw an insignificant amount of power. Probably a penny or two worth a year. Much to low to measure or care about.

2) The charging circuitry, which is all housed in the car, stops drawing power when the battery is full. There is no need to unplug the car. In fact, there are reasons to leave it plugged in: The car periodically wakes up and will top-off power if the battery charge has fallen due to lack of use.

3) It depends entirely on how depleted your battery is. A complete charge will use just over 20KW. See this thread for lots of useful discussion and info: Consumption Monitoring

Brent