woodgeek wrote:Still doesn't add up.
Except I think it is reasonable to assume the following about OP's 12V battery:
- It is significantly sulfated, so the capacity is significantly reduced.
- It was not fully charged when OP left on the trip.
As a result, I expect that OP's battery likely was only storing about 25% to 50% of the nameplate capacity at the time he left, maybe less.
Note that I have directly measured the current draw of the LEAF when off and unplugged
RegGuheert wrote:This morning, I measured the tare current for the LEAF 12V battery with the EVSE unplugged. Here is what I found:
- For the first ten minutes or so the car drew 330mA.
- After about 10 minutes, the tare current dropped to a lower value. It normally sat at 15mA, but pulsed up to 24mA every two seconds or so.
- Occasionally it would rise up to 115mA for a few seconds. I do not know how often this occurs.
According to this post, the published capacity of the factory 55B24L(S) battery is 45Ah at a 20-hr rate. Let's suppose it has about 50Ah at very low rates. If we suppose the tare current is a constant 15mA, then that equates to a discharge rate of C/4000. But since it pulses above that level, sometimes significantly so, the average current must be higher than that.
Perhaps the real average current is more like 25 mA, but that only equates to about 300mW draw, which is significantly lower than your 4W estimate. I think the difference is explained because there is certainly a MUCH higher energy draw when the 12V battery is charged every five days (until it is dead).
Unfortunately, when I later measured the LEAF current draw with the ELM327 installed
, it was MUCH higher:
RegGuheert wrote:So this morning I measured the current draw of the LEAF with it plugged in: 175 mA.
It seems the ELM327 draws about 6X what the entire LEAF draws when off, making the total draw about 7X as much!