Extended Charge not working

[atzmark]

Hello all.
My 2013 Rav4 EV does not do an Extended charge. I get the same range (~65 miles) whether I use Extended or Regular charging. If I do a Regular charge, then select Extended charge, the charger clicks off after a few minutes with a additional mile of range.

It seems the charger is working, but only to 70% charge. It's been to the dealer twice. They say diagnostics show no problem and the reason the Extended charge and regular charge are the same is due to "battery degradation".


Any ideas how I can get a full charge? Thanks, Mark

 

[user 340]

Hello all.

It seems the charger is working, but only to 70% charge. It's been to the dealer twice. They say diagnostics show no problem and the reason the Extended charge and regular charge are the same is due to "battery degradation".


Any ideas how I can get a full charge? Thanks, Mark

You have verified that the on-board charger is working, so the dealer will not be helpful (nothing broken to fix). You should do the "Tony Test" to measure the battery capacity if you want to pursue this further. See http://www.myrav4ev.com/forum/viewtopic.php?f=7&t=1625

 

[davewill]

As the battery degrades, extended charge reduces closer and closer to being the same as regular charge. Try the Tony Test suggested above. I suspect you will find that your battery has simply degraded to the point where you have virtually no "extended" room left.

 

[atzmark]

Thanks for the info...the next step seems to do the "Tony Test" for some numbers.

I don't understand the "battery degradation" explanation. My understanding is that a "regular" 70% charge is used to help reduce battery degradation. Meaning that if the battery has degraded from 42 to 21 kWh, 70% would use ~14 kWh, and using ~20 kWh for an extended charge.

One response implies that charging system has no idea of the actual (degraded) battery capacity. That as the battery degrades "regular " (30kWh) charging rises from 70% to 100% (or more)of the battery capacity (30kWh). Is the charging system that dumb and harmful to a degraded battery?

Thanks again for the input.

 

[user 340]

That is not the situation. Other information on this site (e.g., Tony's RAV4 Range Chart) shows the nominal extended charge capacity at 41.8 kWh and the standard charge capacity at 35.0 kWh. Thus the standard charge is ~84% of the extended when new.

Driving style variations may also be causing some minor masking of standard and extended charge capacities. The Tony test eliminates this by using a constant conversion between kWh and range.

 

[smkettner]

Extended range working or not is just not going to add much anyway. You will get 4 to 8 miles extra, big whoop. And maybe none at this point.

 

[atzmark]

I'm still confused. Using the tgreene's numbers of 41.8 and 35 kWh for normal and extended charge.

If the battery is 50% degraded, then an normal charge would be 17.5 kWh, an extended charge 20.6 kWh.
And it would take 30min-hour to add those 4 kWh.

Other responses imply that Only the Extended chaged is reduced to zero as the batttery degrades. Once the battery degraged to 70% or more extended "stops working", and at 60% the battery is being overcharged, accelerating battery degration.


So does the onboard charger adjust as the capacity of the battery changes, charging it to 70% of (degraded) capacity, or not?

Thanks, Mark

 

[smkettner]

Just drive. Enjoy the car. It is what it is.

Or trade it in... is what I did.

 

[dstjohn99]

I'm still confused. Using the tgreene's numbers of 41.8 and 35 kWh for normal and extended charge.

If the battery is 50% degraded, then an normal charge would be 17.5 kWh, an extended charge 20.6 kWh.
And it would take 30min-hour to add those 4 kWh.

Other responses imply that Only the Extended chaged is reduced to zero as the batttery degrades. Once the battery degraged to 70% or more extended "stops working", and at 60% the battery is being overcharged, accelerating battery degration.


So does the onboard charger adjust as the capacity of the battery changes, charging it to 70% of (degraded) capacity, or not?

Thanks, Mark

Sorry, you are missing the way it works. Normal charging will take the battery to 35 kWh. Extended charge will take it above that to 100% capacity. When new that is 41.8 kWh. As the battery degrades, normal charge will still charge to 35 kWh, but extended charge is reduced. With further degradation, below 35kWh total capacity, a normal charge will charge to the max battery capacity (100%), whatever that might be.

 

[atzmark]

Thanks for the clarification.

I'm surprised that with 15% or more degradation the battery is being charge to 100% capacity, or essentially an Extended charge. My owners manual says this can/will shorten the life of the battery, as opposed to an 85% capacity charge.

Any way to keep from cooking the battery to 100% charge every time it's charged?


Thanks for the info, Mark

 

[atzmark]

Thanks for the clarification.

I'm surprised that with 15% or more degradation the battery is being charge to 100% capacity, or essentially an Extended charge. My owners manual says this can/will shorten the life of the battery, as opposed to an 85% capacity charge.

Any way to keep from cooking the battery to 100% charge every time it's charged?


Thanks for the info, Mark

 

[jimbo69ny]

Thanks for the clarification.

I'm surprised that with 15% or more degradation the battery is being charge to 100% capacity, or essentially an Extended charge. My owners manual says this can/will shorten the life of the battery, as opposed to an 85% capacity charge.

Any way to keep from cooking the battery to 100% charge every time it's charged?


Thanks for the info, Mark

I'm not sure where to start.. lol

You arent cooking anything. The battery has a thermal management system that maintains temperature. But that is totally unrelated.

Your battery's BMS will monitor the pack. You aren't going to some how give it more capacity than it has.

If you are worried about it, dont use extended range mode. You know how to turn it on and off right?

How many miles are on the car? I haven't seen or heard of a car with more than 15% battery degradation yet. Someone might have experienced it but I haven't seen anyone complaining about it yet. But its only a matter of time. As these cars get older and the battery sees more cycles degradation will happen.

 

[n3ckf]

I notice my battery is in this condition when it would actually stop charging correctly if you selected Extended Mode.
Not selecting that seems to work perfectly.

I also notice from my charge curvethat the battery is tailing off charge rate before it reaches the end of a standard charge (it never did this in the past).

So the car runs fine, its just the range is less than it used to be. Thats just living with an EV for 6 years now. I havent done a Tony Test recently but it *seems* like the car is about 10-15% less range-ful than when i bought it. I mostly drive in the mountains (I retired after 5 years of owning this car) and the shorter range isnt an issue because i use this car for around town (and in weather i dont want to drive my Tesla Model 3 in)

 

[hokiematt]

It's worth noting the ambient temperature when you charge is quite important: a cold battery won't hold as much, so extended charge will appear to have less capacity. In summer, full standard and extended charges might show 35 and 41 kWhr available, but during the winter I see more like 35 and 37 kWhr between the two modes. Coupled with lower efficiency (~2 mi/kWhr) from running electric heat, and the standard vs extended range shown on the GOM is barely noticeable.

 

[n3ckf]

Yeah when i ran that charge curve it was probably 32 degrees F. (My car is usually outside, and its about freezing every morning here now).
So yeah. some of the apparent degradation is due to that.

So just as a comparison my GOM usually shows between 68 and 72 miles now for a full "standard" charge. I think the range is probably a little more than that really but in summer when it was new i used to get ~96 miles up here. (you use more power up here becuase you're always driving up and down hills, so its never in the 120 range that it was when i was driving it new in the Bay Area.)

 

[TonyWilliams]

Your extended charging is working fine, and so is the battery.

All the Rav4 EVs are degraded 5-10% already, just due to age. Extreme use, or high ambient temperatures might have further reduced the battery capacity. And, finally, actual "cycles" / miles will degrade the battery. Time, heat and use... just that simple.

As the RAV4 EV fleet approaches 100,000 miles, the batteries will likely be in the 10-20% degradation area, and with a few cars approaching 150,000 miles, 15% + is very likely.

Do the Tony-Test, and quit focusing on the daily GOM value. It's sad to think how many people sold or traded their RAV4 EV because, "I used to get 120-140 miles on the GOM, and now I only get 70, so I sold it". Sadly, they just didn't know, or didn't bother to ask if that was accurate.

Once you PROPERLY done the Tony-Test, I'm confident that your fears will subside.