Does heating while charging slow charging rate?

[Luft]

Sometimes when charging at a public L2 charging station I will turn the car on so that I can run the heater. Does that slow the rate that the EVSE charges the battery? I have a 2011 LEAF so only 16 amps. I see that the power use can spike to over 4 kW.

 

[davewill]

Most definitely, the heater will slow the charge rate considerably. The heater draw what it draws. If it's less than the on-board charger is providing, it charges the battery. If it's more, it discharges the battery. L1 provides 1.2kW, L2 provides 3.3kW. I've seen the heater draw 5kW, but typically settles in around 1.5kW. As you can see, on L1, you might not charge the battery at all, while on L2, once it warms up, you would be charging the battery, but more slowly.

 

[Geraldk]

Once I get close to 100% or around 11 bars, I turn on Climate control to slow the charging down. That way the car does not sit at 100% very long. I have just been using L1.

 

[nosuchthing]

I have noticed that the third blue light begins to blink when preheating even though the battery charged all night beforehand and it was 100% before the heater went off.

What is the meanining of that? Does heating up discharge some of the battery and now the battery is again charging/catching up? It certainly appears so.

 

[Deleted member 3147]

I have noticed that the third blue light begins to blink when preheating even though the battery charged all night beforehand and it was 100% before the heater went off.

What is the meanining of that? Does heating up discharge some of the battery and now the battery is again charging/catching up? It certainly appears so.

When you start pre-heating, the heater will draw more than the 3.3KW coming from the charger and the battery will start discharging to supply the difference. After some time, depending on ambient temperature, the draw will drop below 3.3KW and the battery will start charging again. Given enough time time, the battery will reach 100% SOC again and the charger will throttle back to supply only what the heater (and other systems) are drawing.

I'd certainly like a mode where the charger only supplies the pre-heat (heater throttles back) and leaves the battery alone, but AFAIK, this is not available.

 

[nosuchthing]

Anyone's guess how long it takes before the process falls below 3.3? In other words, how much time should I allow to leave with full, equalized battery and preheated car?

 

[dgpcolorado]

I have noticed that the third blue light begins to blink when preheating even though the battery charged all night beforehand and it was 100% before the heater went off.

What is the meanining of that? Does heating up discharge some of the battery and now the battery is again charging/catching up? It certainly appears so.

The charge light patterns have a number of meanings. From the manual:

When the indicator light 3 flashes
The indicator light 3 flashes when the 12-volt battery is being charged. The indicator also flashes when the following systems are operating:
• Climate Ctrl. Timer
• Remote climate control
• Li-ion battery heater

Page CH-27

Yes, the heater will discharge some of the battery because 3.3 kW isn't enough when it first warms up, after which charging will resume, albeit very slowly near 100%. But that isn't the reason for a flashing light 3 which is just telling you that you have the CC timer or remote climate control activated. The difference between CC timer and charging is that lights 1 and 2 will be off when flashing light 3 indicates that CC function is on.

 

[dgpcolorado]

Anyone's guess how long it takes before the process falls below 3.3? In other words, how much time should I allow to leave with full, equalized battery and preheated car?

That depends on the temperature of the air outside the car (the starting heater bottle temp) and inside the car. There is no one right answer. In your mild climate a half hour of preheating might be enough to get the battery back to near full.

As an experiment, set your end-time-only charge timer for a bit later than the departure time on the CC timer. Once the CC timer finishes you might see charging resume. You can then measure how long it takes.