Anyway to charge battery beyond 85% SOC

Toyota has chosen to maximize battery life, I am unclear why you would choose to reduce it. Left alone, you have a great warranty that I would not choose to risk.

I am betting that you are leaving the house fully charged, then going downhill, which attempts to charge it more, so you HAVE to burn off charge. You could try not to fully charge the car or coast in N, which should not attempt to regen.

If instead of lieing to the ECUs that they could do more regen into a 'full' battery, you chose to lie to the ESVE that your Prius was 'full' when it still had room to get down off the hill, you would keep the car stock.

 

The reason you can't is to preserve the HV battery. The batteries in your laptop, mobile phone or cordless drill are similar technology to that in your car but they only last a couple years. The reason is they are fully charged to 100% and decharged to 5% or zero. The same would apply to your car if that full range of charge was used, but a new battery in your car is $4,500 not $25! I'm sure your laptop battery could last 10 years if it were managed in the same way as your PIP.

As such, the car manufacturers restrict the window to that magic zone where you get less range but a much longer service life. You could probably eke out 25 miles of EV out of the PIP if you charged it to 100% and ran down to 5%, but you'd need a new battery after 18 months.

It's all one big balancing act.

 

From my house (where I fully charge my Plug-in) I go slightly up a 300 foot drive, then down a rather steep road about two short blocks to a stop sign. Sometimes I notice the ICE has turned on at the stop, and sometimes not. I am looking for a pattern. Currently I think that if I apply the brakes a little from the top and keep my speed around 20 MPH, then no ICE. However, if I let the car go at the top, reach around 35 MPH and then brake to a stop, the ICE turns on. Hope this is helpful to you.

 

Your over charging the battery and the charge needs to be burned off. Try setting your temp to LOW if it's set anywhere above that it can call for heat when you turn on just the fan, and this will also bring on the ICE.

 

Grumpy is right. you do not want to mess with Toyota's settings. they are the current undisputed kings of Battery management and ya, the #'s are skewed towards longevity and reduced warranty claims.

i just left the cellular industry and cellphone batteries are designed to be overcharged simply because they add a bit more talk time which is what most people want. this gives them a rated cycle life of 300-500 charges. if you are a heavy user, your battery will last a year.

now, i am experimenting with my battery. i have a droid bionic which is a power hog on LTE but i got the phone to take advantage of the data transfer speed so i immediately got an extended battery and am attempting to charge it to no more than 90% as much as i possibly can. granted it will take another year or so for me to determine if i am doing any good but i have never had a battery last much longer than a year without a very noticeable drop in capacity and yea, i do use my phone a lot.

 

When I rebalance Prius HV modules the protocol is to slightly overcharge the modules using a 3 cycle discharge-charge process. This allows the lower SOC cells to catch up while the higher SOC cells dissipate the excess charge as heat. You can do this in up to every other module (14) as long as you provide cooling air flow and avoid overheating the cells by charging them at a low rate of charge (the modules need to be clamped as they are in the HV battery to handle the internal pressure build up). After the 3 cycle protocol the modules are near 100% SOC, but this would not be practical to do as a regular practice for longer EV range.

This process, when done for all 28 modules (in a Gen2 or Gen3 Prius battery that has not yet failed, if any modules have failed they can be replaced with one with the same capacity as the others.) followed by a calibrated discharge of all of them to the same voltage, restores the HV battery to an almost new condition.

JeffD