Charging Strategies: Best Time of Day?

I've been using the charge timer to start at about 5AM so that it is ready to go when I get in the car around 815-820AM. I do this since its mentioned in the manual on page 93:

When I get to work, if I think I may be driving at lunch time, I've been setting the charge timer to start at 10AM (I get to work around 9AM). I thought it said something about charging immediately in the manual, but I cant seem to find it (although I clearly remember it was discussed here). But I figured that if I start charging at 10AM, it gives the battery an hour to "cool down". I may not have a full charge before heading out at lunch, but I usually dont stray too far away from work for lunch anyway.

If I'm not sure I'll be driving at lunch, and since its warming up here (like today), then I'll set the charge timer to start at around 2PM, so its ready to go when I leave work. I'm toying with the idea of not even bothering to charge at 10AM and just let it charge at 2PM, regardless of what my lunch plans are.

The charge management available on the Advanced model would come in handy for me.

 

So far, I have used the "finish" time on the charger. In my case, that is 5:50 am, so it has had plenty of time to cool down if I happen to be out late at night. I gather it decides how much charge it needs, and backs up the start time to compensate. There is supposed to be an advantage in battery management by having it freshly charged just before you leave.

 

I set mine to start at 4am too. Completes at 6.30am or so. My off-peak electrical rates ends at 7am.

 

Does PG&E have a reasonable package that works for the PiP; that is, does not require a separate meter, and does not significantly raise the day rate?

 

I don't think so. But E9A is actually pretty good in winter, with the rates in all tiers lower than E1's flat-rate.

The killer however comes in the peak rates during summer. Nevertheless, if you don't use much electricity between Mon-Fri 2pm to 9pm in summer, then E9A would still be good. The peak rate is the only time that E9A is higher than E1. The rates at all other times are lower than E1.

Summer is defined as 5/1 to 10/31. Winter is 11/1 to 4/30.

I'm on E9A but I have solar so in the afternoon, I end up selling electricity to PG&E at the higher rate. Works for me.

 

Since the battery generates far more heat discharging than charging, its always good to let a lithium based battery "rest" before recharging. A good nighttime cooling "soak" before charging is best except if the temps drop into the single digits and below. The mass of the battery will keep it fairly warm for a while. Just out of curiosity, did anybody sit in the back seat after they got home to see if there is any residual heat there?

 

Another consideration -- especially once a lot more people plug in their cars -- is the power generation and the grid capacity.

Charging during super off-peak periods (generally after midnight on weeknights) will help ensure the power company does not have to fire up additional power stations. There is more than enough power plant capacity in existence already today to charge the cars if they are charged late at night.

However, charging during peak periods can contribute to "peaker" plants being brought on line. These kinds of power plants tend to be much more polluting than the plants that run for baseline power generation. Also, if we all charge our cars during peak periods, the power companies would eventually have to build additional capacity.

 

You want your battery warm when you start, its more efficient that way. So for best range, you want to finish just before you leave. I see a 3-4m drop in my Volt if I charged it the day before (e.g. weekend) compared to having it finish just before I leave.

Have to balance just in time charging, that your power rates if you which to E9A and the risk of needing to leave early.

 

Way to go!!! :rockon: