I have a car that has one bad module per Dr Prius and Techstream. I have been watching Dr Prius like a hawk when driving and I see when the Vdif gets above 2 I get the triangle. So I have been stopping resetting the code and and charging my battery using full throttle/braking to get the SOC and the Vdif down before that happens. Am I at risk of damaging anything if I do this too much? I can't seem to find out.
You can keep clearing codes and driving with NiMH chemistry for as long as you want without issue as long as you makes sure to keep the pack from overeheating, as in above 125' F.
IMHO; those modules are tied together in series; yielding your 200+VDC. When you knowingly run the car like that; your forcing the rest of the "good" modules to work harder, making up for the dead one. Any modules that are borderline from failing will probably do so very soon, since your forcing all of them to work harder, with that "dead-weight" in the series. It's your car and your money - do whatever you like with it......
Work harder? The warning light and error code is triggered by a minor voltage difference between blocks, which is within normal operating parameters for these packs, just getting close to the threshold of inefficiency. A pack doesn't work harder just because one cell out of 168 cells is starting to fail and it won't work at all once that cell entirely fails. Back when I'd drive around with NiMH packs I was testing / rebuilding I could have days where I'd get warning light 3 times in one day and then could go 3 weeks without an issue. Electrons malfunctioning are not the same as mechancal parts failing.
Why would an OEM throw out a warning - if everything is honky-dory????? You can just do what back-woods mechanics do; put a piece of electrical tape over the warning lamp. Problem solved....
No you can't because the warning light for voltage being out of balance shuts down the entire hybrid system and turns the hybrid cooling fan up to full speed so all you got is gas engine power which is not enough power to go up a steep hill. And that's only going to happen during a high amp load from hard braking or hard acceleration. Soon as you clear the error code and you aren't having a high amp load into or out of the pack the vehicle and the bad cell will behave normal with no risk of causing further damage. As in the car is designed to protect itself and you have to over-ride that system many times before the pack overheats and becomes damaged.
Trouble codes and warning lights do NOT come on when everything is within normal operating parameters. They come on when things are NOT within normal operating parameters as defined by Toyota engineers.
You are at risk of one of the hybrid battery modules going POP and not being able to drive the car. Or another word, being stranded somewhere at the worst possible location and at the worst possible time. How long have you been driving the car since the first occurrence of this problem? Since you know that there is a problem, why don't you get the hybrid battery repaired or replaced?
Wow, thanks for all the responses and opinions. I frankly don't care about the health of the battery pack, I am fairly certain that the one low module (it's only one according to Dr Prius and Techstream)is in time going to have an effect on the others, and I will be pulling the pack and either putting a new reconditioned one in or just changing out the bad module.. What I am concerned about is the damage that I may do to the Inverter or Drive motor by doing a "force charge" or whatever the term would be to the car. Can I damage the inverter or the motor or something else if I do this several times a day? I don't want the charging stuff ruined in the meantime.
IMO, doing a "force charging" of the hybrid battery will cause that one bad battery module to go POP sooner then if you do not do the "force charging". Just let the car trigger the P0A80 code and then reset it if you need to. How long has it been since you got the first trouble code for the hybrid battery? How much driving do you do?
IMHO, NO because that's what those components are suppose to do. I would monitor the ECT to make sure your not overheating the engine, since all you have is a dummy lamp, that lights up around 248+F - so you'd avoid popping a head gasket during those rev. sessions. Good Luck... FWIW; you can force-on the cooling fans by turning ON the AC system to keep the motor temps down.
Has the OP opened up the pack to inspect the bus bars and nuts? It might just be corrosion on those components and not failure on the module. Might.
I watch the engine coolant temp as I do the charge and do not see any significant increase. I've gotten pretty good at knowing how to drive the car so I charge the batteries when possible, so I rarely have to do this now that I know how to drive it and monitor Dr Prius realtime.. I realize I am defeating the purpose of the hybrid technology. Good knowing that the engine/inverter component should be OK. As far as just resetting the trouble codes, that works as long as I stop and shut the car off when I do, otherwise the system seems to go into some sort of "limp home" mode and will only put out a limited charge. I just want to say I don't plan on this being an ongoing procedure. I have a small farm here and we have just gone thru an insane typhoon like storm and today is first day I've seen significant sun in 10 days. I received over 30 inches of rain in 5 days. So this car is secondary to just getting back to normal. I just don't want to ruin it in the meantime
The engine temperature isn't what I was referring to. The hybrid battery pack temperatures on Dr. Prius app are the temperatures you want to be concerned with.
I do understand that the warning lights and trouble codes will come on in any car when the detection conditions are met. The automotive manufactures design them into the car for a reason. The engineers that designed the car determine when the warning lights and trouble codes should come on. Are you saying that you know more about the hybrid system in the car than the engineers that designed the car? Those design engineers are the ones who determined when the warning lights and trouble codes come on.
