Study Ideas - Battery Degradation

Similar here, which makes sense. Same model year and same neighborhood. But my typical range in the late afternoon commute is about 9.5-10 miles. It's 9.7 miles home from work and most days I make it. But the hotter it is, the harder it is to not run out of juice because the A/C is practically roaring. Mornings going to work, I usually have 1.2-2.4 miles left this time of year.

BTW, I just did another test run.
Same temperatures.
Not wet, so windows open, fan off.
Slightly less traffic.
Similar route and speeds.
14.2 miles.

Conclusion: At a #2 setting, the fan doesn't seem to make a lot of difference, but there were other factors, so that's not a conclusive conclusion. If you get my drift.

 

how much difference between l1 and l2, and why?

 

With the PiP I would say L2 (or 230 V here) is about 89-91% efficient (9-11% losses) while L1 is about 82-84% efficient (16-18% losses).
With the PiP, L1 max. current is ~13 A (and longer charging time due to the low voltage) while L2 max. current is ~10 A (and shorter time due to the high voltage). Losses go with the current squared so this is IMO the main reason for the difference.

 

thanks, but i'm still not clear. are we measuring the amount of electricity to fill the battery, or the total amount needed to accomplish it?

 

The 'payable charge' i.e. from wall.
The charge the battery can accept was 62% of 4.4 kWh or 2.7-2.75 kWh when new, however, less in time and use.
I recall members here reporting ~3.3 kWh charge from wall with L1 when new, 2.73/3.3 is 83% or 17% losses.
I had 3.0 kWh from wall @ 230 V when new, 2.73/3 is 91% or 9% losses.
The charge the battery can accept is reduced in time and use, so is the amount of charge from wall to charge from 'empty' to 'full'. I am pumping today about 2.55-2.6 kWh from wall - 87% of 3.0 kWh or about 13% reduction.
P.S. The 62% mentioned is IMO true today as well but the battery is not a 4.4 kWh battery anymore

 

will you please rest this in marks other thread, 'study ideas'?

 

Wouldn't a full charge be a full charge regardless, other than the extra time it takes because of efficiency losses of 110 vs 220

 

as mentioned earlier, you can start from different points in the hv portion.

 

Guess I'm not a battery technician

 

ditto.

 

Double ditto. That said, I think the best bet would be to use a scan gauge or something like it to check SOC before and after charging and do it lots and lots of times while recording the power consumed from the outlet at each charge. That should give you a trend, but it's a lot of work.

 

my ev estimate hit 15 today, haven't seen that in a long time. the weather has been spectacular.

 

This is totally in line with what my PiP charges every day (my OpenEVSE reports kWh every charge).

 

can you post some numbers in marks other ongoing thread? it would be helpful to other owners.

 

Well, I drive to work every day.. 600ft elevation drop over 12.8 miles (which helps a lot).. I'd say I make it to work on all electric about 98% of the time (so only 2-3 times a year - provided I'm not carpooling or deviating from my 12.8mi daily route). I used to have days where I made it with 2-3mi left.. but my range estimate has kind of settled to around 11.2-11.5 miles year round. Nowadays, if I can make it with 1.2-1.5 miles left, thats pretty good. Some days I'll make it with 0.1mi creeping into the parking lot at work.

I have a few factors that make it difficult to compare. First, I'm on some lightweight 17" wheels using Bridgestone Ecopia EP422 205/50/17 tires. I definitely dont think these are as efficient as my stock setup. However, I also know my driving has gotten "better" over the past 5+ years and I'm much better equipped mentally to shrug off the one-finger salute now (I guess it comes with age). Although I do drive the speed limit, thats not good enough in my 'hood. And lastly, I hit like 15+ traffic lights. I usually get stuck at the same ones.. but on days where I hit a lot of green lights, I definitely make it farther/end up at work with more juice.

But having said all that, I dont FEEL like I've lost too much capacity. Subconsciously I'm sure I'm making adjustments since I'm constantly calculating my range/distance/remaining capacity (for example, I know if I make it to Gas Station X with 7miles on the trip odo and have 6mi EV remaining, I'm in good shape). On the way home, I can never make it all the way, but I usually run out around the same spot, give or take 0.25 miles or so.

So yeah, if we were just going by distance, I'd probably be telling you I dont THINK I lost much range.

 

thats what the PiP is supposed to charge.. they leave headroom on the 4.4 pack as to increase the lifetime of lithium cells.. my Thinkpad laptop does the same thing. This is why the first gen Leaf's have problems with battery longevity as Nissan did not do this.

 

if you teach me how to paste, i will do it. i'm still doing addition on my fingers. does danny know how how to paste?
besides, if mark hadn't started 2 threads on the same thing, i wouldn't have to paste in the first place.