Charging - what's better for the battery?

I think technically, a lower charge rate is always marginally better for any battery than a higher charge rate. It has to do with electrode deterioration I believe. I'm not sure there is a practical difference between the L1 and L2 chargers, because they are both engineered to ensure long battery life.

 

When I purchased the PIP, the dealer said that charging at 120 was slight more beneficial and easier on the battery than charging at a high rate. Basically what Greg said above...slower the charge, better off. Now, whether there is actual data to support that, I have no idea...but it does sound logical...

 

Compared to what's being slammed into the battery during regeneration, the 2kw the charger is pushing during L2 charging is insignificant.

 

Interesting point. With the right downhill one could probably charge the battery in well less than an hour. (I have no where there is such a hill ) What to you suppose the regen charging rate maximum is?

 

I think the battery is robust enough to handle a few ram-charges once in awhile. A daily routine of doing such things would be a very different story.

 

Looking at one of my past Torque logs, the max regen I hit was 146.14 Amps, while voltage was reading 209. That would put it around 30kW? So if you could sustain that level of regen, top off an empty battery in 6 minutes? I'm sure someone will check my math

 

Exactly. Today, coming down a steep grade from Rock Creek Lake to US 395 I went from zero EV miles to 9.8. In less than half an hour.

Does anyone really think that Toyota engineers didn't factor heavy regen currents into the battery design?

 

I frequently go from 6300 feet to 1500 feet, down the mountain in about 25 minutes. This always completely fills the battery. Just hope the Plug-in is designed for this. At 30,000 miles and two plus years, no problems.

 

What's the charge time with 110 volt? 3 hours? I can't see the higher voltage chargers flying off the shelves.

 

Closer to 2.5 hours on 120v. Most of it happens in the first 1.5 hrs.

I'd say it's far more important to not leave the battery at a high state of charge for long periods of time in direct sun or hot weather. But none of these issues really worry me that much. I try to keep it topped off most of the time because I never know when I'll want to go somewhere.

 

My PiP charges at a fairly constant rate for 2 hours then at about 1/2 rate for a few minutes. Here is a chart showing consumption rate in watts. Of course there are other things going on in the house but a graph like this is usual for a full charge of about 3 kWh. You can see the charging starts at 2:15 AM and goes at full rate (perhaps with a small increase) until 4:15 AM then at about 1/2 rate for around 10 minutes.

 

I've noticed when I'm watching the charge that sometimes the charge rate will drop out to 0.0kw for a few seconds then resume again. slowly climbing back to either 1.1kw on the 120v charger or 1.9kw on most of the 240v chargers I've hooked up to. I try to drive in ev whenever possible and my scangauge show 85% SOC when charging is finished and about 25% SOC when there is no ev charge left. I'm still not sure what the bottom SOC is yet, I've only had the hv battery indicator down 2 or 3 bars at around 22% SOC on the scangauge.
If the cells / sub packs in the battery get out of balance they can be rebalanced by going beyond the cars cutoff voltages both high and low with a special charger/discharger designed specifically for rebalancing the packs.. But if that is done on a regular basis the batteries will eventually fail from exceeding their max charge discharge cycles, which I've heard is around 10,000 cycles.
I've also heard that the toyota batteries are very resilient compared to some of the other configurations at least the NiMH ones anyway. The other cars Lithium battery configurations may be starting to catchup, put I haven't seen any data yet on the actual in car performance and longevity of the Lithium packs.

Phinergy, Alcoa, Demonstrate 1000-Mile Range-extending Electric Car Battery | Transportation Evolution Institute

 

This periodic dropping to 0.0kw is a normal part of the charging cycle for LiIon batteries. There are some parameters which can only be reliably measured when not charging, so the charger will briefly stop charging, get the readings it wants, and then resume charging.

 

I believe a L2 charger (240V) has less line loss than a L1 charger. Thus, you have to balance your concerns about over-stressing the battery with efficiency/minimizing energy loss. As others have said, I doubt that a L2 charge would have any significant impact on battery life.

 

added todo list: find out what those parameters and default read ranges are.

 

I sure am glad that I don't really care about those kind of things. My brain just can't handle it!

 

As someone who's worked in software for his entire professional career, a particular version of software needs to ship, eventually. And, sometimes hardware needs to be loaded w/something that at least works, mostly. And, in some cases, a sufficient inventory of hardware needs to be built, distributed and accumulated in the channel.

Some bugs will be postponed until future releases and that update might be released fairly soon afterward or even right when the product is released for sale to customers.

Sometimes certain changes are fairly big, might be destabilizing and require more time for extensive testing and "bake time", so those will tend to get deferred until it's ready.

If one keeps iterating on fixing bugs, the product may be very late or never ship or suffer from feature creep. The line has to be drawn somewhere and is re-drawn in the future.


As for Patch Tuesday, see
Microsoft details new security plan - CNET News.