Time To Charge Display is Bogus

This must have been discussed before. Please forgive me for repeating.

My Leaf 2013 SV has 55% charge left, according to the dashboard. It is set to battery saving mode, charge to 80%.

The dash display shows Time To 80% Charge:
240V 6kW 1:00
240V 3kW 1:30
120V 5:30

I would expect 1/2 the time for 6kW as 3kW.

When the battery is even further discharged, the display is even more bogus. In other words, it shows that the times to 80% for 3kW and 6kW are always very close together.

What gives?

Bob

Bob said:

This must have been discussed before. Please forgive me for repeating.

My Leaf 2013 SV has 55% charge left, according to the dashboard. It is set to battery saving mode, charge to 80%.

The dash display shows Time To 80% Charge:
240V 6kW 1:00
240V 3kW 1:30
120V 5:30

I would expect 1/2 the time for 6kW as 3kW.

When the battery is even further discharged, the display is even more bogus. In other words, it shows that the times to 80% for 3kW and 6kW are always very close together.

What gives?

Bob

Click to expand...

I think that there are several things at work here.

First, the time to charge estimates are very rough and always seem to overestimate the actual time required to charge IME.

Second, if the estimates are given in half hour increments (not sure about that) the numbers may be an artifact of rounding.

Third, 3.3 kW charging is a bit more than half as fast as 6.0 kW charging.

Fourth, when it comes to 100% charging, the tapering as charging nears completion makes the size of the on-board charger irrelevant. This shouldn't be much of a factor in 80% charging but it might play a small role if the tapering starts that early.


Of all of these, the fact that the estimates are very rough and "coarse" is likely the main reason for the apparent inaccuracy.

You might want to calculate your own figures for how many % of charge you add per hour using various types of EVSEs. You could come up with much more precise information for your car. Do be aware that different Level 2 EVSEs can have different charge speeds since some on three phase electrical service are at 208 V and those on two phase service are usually 240 Volts. That can vary charge speeds.

And keep in mind cell balancing can really drage things on as well if they are including that int he "To 100% Charge" figure.