Should I be worried about electrolyte loss?

I thought the HV battery was dry?

 

Heat will hurt the life span of NiMH batteries, but not because of electrolyte loss. The HV battery is cooled by cabin air, so use your air conditioning during hot weather to keep the battery cool.

Tom

 

No point in worrying, since there's really nothing practical that you can do about your traction battery's life. A reasonable number of Classic batteries have failed, in some cases apparently due to electrolyte loss from bad module sealing. It appears that 2G battery modules are more robust and should have a longer life.

Southern California has relatively moderate climate with summer temperatures into the 90 degree F range. In that season I frequently hear the battery cooling fan running.

 

You can minimize the heat stress by:

1. parking in shade - no reason to solar heat the interior.
2. use "B" when descending large hills (+160 M. hills) - once is not too bad but on a long trip through a lot of hills and mountains, the repeated charging can heat up the traction battery.
3. Mostly an issue for NHW11 batteries - these first generation batteries have a lighter duty case.

Feel free to look through my battery work.

Bob Wilson

 

A NiMH (and NiCd) are wet cells. They use a basic electrolyte, mostly Potassium Hydroxide and water, but they say it contains a bit of Sodium Hydroxide.
The Prius cells are "sealed", but have a pressure vent just as all others I have seen do. This is to prevent an explosion in the event of catastrophic failure of the battery charge/discharge control (for example, a short).

-IF- you managed to get them hot enough (unlikely) they -could- loose electrolyte. The battery management system reduces battery use when it gets too cold or too hot. I haven't noticed the reduction when it gets cold (Pearl still backs out of my garage just fine even when the battery is at -10C and reverses just fine when parked and at -30C - before - the engine starts). I have read reports of the reduction when it gets too hot. The car becomes a bit "sluggish".

Most electrolyte "loss" is to irreversible chemical reaction, mostly oxidation and subsequent loss of the H2 (the molecule is very small and will diffuse through most seals given enough time). This is a very slow process, resulting in battery life of well over 5 years, barring other failures. This could be considered "the life of the car" in most uses.

So relax, "DON'T PANIC", and be happy.

 

Have you considered adding a bottle of gatorade to the fuel bladder to replenish the lost electrolytes?

 

In practical terms, the NiMH isn't the thing to worry about. The little 12 vdc battery will croak long before you have to worry about the traction battery

 

And it's a multi-speed fan. I forget if it's 3 speeds or continuously variable, but the battery electronics controls the fan operation.

 

thats something new to me

so you say the prius battery´s wil last 5 years and then start do downgrade...

 

To the best of my knowledge, no one has published any life-time studies of our Prius traction batteries except for the Arizona Fleet studies. Even in these studies, it was just the NHW11 and Honda Insight. They may have also done first generation Honda Civic hybrids but I'd have to go back and look.

Bob Wilson

 

The OP may be worried about electrolyte loss, but how about hair loss? Look what happened to Jayman.

Tom

 

Oh, fun-ee guy ... he he he ...

Just wait, you'll have a chrome dome soon enough. I can picture it now, you'll wake up one morning, lift your head from the pillow, and those thick locks of hair will REMAIN on the pillow.

At least, that's about how quickly I lost my hair ....

 

radioactive jayman?

 

No, just receded at a sadly young age. I think qbee42 enjoys teasing me about my chrome dome.

 

Me? No, I would *never* tease anyone about anything. I am simply too nice to do something like that. :evil:

Tom

 

Don't forget the part about my brute strength ...

 

I thought loss of hair took care of that?

Tom