Fast Charging the NiMH battery - COOL TIP

[Stocky]

Oh wow - picked up my new baby about 5 hours ago – now I am a real Prius owner - WUHU!!!!

I read with interest that there is a lot of concern over running down the NiMH battery in various forums. I think I found an easy fix.

To FAST CHARGE your NiMH Battery.
1. Start the car
2. Put it in Drive
3. Depress both the brake and gas pedal simultaneously to the floor.
4. The car will recognise that you want to charge the battery and move into a special "fast charging" mode.
5. This can take up to 5 minutes depending on the charge state of your battery (you can even get it up to 100% - FULL GREEN)
6. The car will NOT overrev and will adjust the engine speed back as the battery charges.

I suggest you do this only once in a 3 or 4 day period, because despite statements to the contrary, the NiMH does have a memory and I am not sure what the fast charge will do.

Save it for emergencies, better to be safe than sorry.

[KTPhil]

What is your source for this method?

[V8Cobrakid]

yeah.. and the engine automaticaly stops turning as fast when it's full.. i found that parto be kinda cool when i found this out several months back.. it's completely full. good if you are doing autocrossing at the time and, not worried about your mpg or enviromental impact.. but bad for most people on this site. It drops your overall mpg by a decent amount. that's a lot of 0's going into the mpg calculation that would normally be at least 15s..... punching it and riding the car at max speed for about a min is the same amount of fuel it uses.

I would also believe that doing this on a regular basis might possibly shorten your battery life. needless to say, i don't do this anymore

Stocky: unless you have text, i don't think the system goes into a smart mode to charge. I wouldn't put it too far past Toyota to incorprate this.. but from i notice in normal electric motor/generator behavor, time and constant speed is a factor that usually results in a quick charge.

[naterprius]

This is actually very, very useful if I have a mountain climb ahead.

Thanks much!

Nate

[efusco]

<div class='quotetop'>QUOTE(naterprius\";p=\"71067)</div>

This is actually very, very useful if I have a mountain climb ahead.

Thanks much!

Nate[/b]

And that is the only reason I can think of to do this. Otherwise it's exteremely inefficient use of the ICE and battery and creates a ton of emissions for no reason.

[DaveG]

Someone on the Yahoo Groups list had also mentioned that this may cause extra wear with components overheating as the car is stationary.

I have no information either way, and am just repeating what I've read.

Needless to say, as Evan has mentioned, it's not something that needs to be done because the battery will recharge itself during regular driving, and unless you are racing (in which case it was foolish to buy a Prius), there's no reason to force-charge your battery.

Dave

[V8Cobrakid]

i've never had the prius fail me with a mountain climb. it would be more efficient to just drive up the mountain instead of charging. either way, the car will probably give the electric motors priority when going up the hill (utilizes electric as much as possible) and the battery will last the same amount of time. just take it easy up hills and cruise down the other side. it will at least be a natural charge and drain on your battery.

poor battery. always taking the beating for our poor driving habits.

better it instead of gasoline

[efusco]

<div class='quotetop'>QUOTE(V8Cobrakid\";p=\"71086)</div>

i've never had the prius fail me with a mountain climb. it would be more efficient to just drive up the mountain instead of charging. either way, the car will probably give the electric motors priority when going up the hill (utilizes electric as much as possible) and the battery will last the same amount of time. just take it easy up hills and cruise down the other side. it will at least be a natural charge and drain on your battery.

poor battery. always taking the beating for our poor driving habits.

 better it instead of gasoline [/b]

That's an excellent point V8...the improvement in climbing ability with a force charged battery over one at mid-level is going to be negligible.

[Stocky]

I never said that it was good for gas or the emissions. I just said that if you get into a bind with your NiMH battery going flat when climbing hills or whatever, then this will get you out of it.

Actually, I found it surprising that engine was just running at a real fast idle when I did it, then dropped away to a normal idle, so I don't believe the impact on MPG is as great as you would first surmise.

The Toyota dealer told me that the car DOES go into a special mode, he specifically called it "fast charging mode". However, someone with the set of manuals may be able to post a confirmation or rebuttal.

When I took delivery of my Prius this afternoon (WUHU), I spoke with the Toyota Service Manager. He confirmed that it is the way the service guys charge the battery when they have problems. Go figure.

Again I reiterate, I don't know the "real" impact on the battery, so caveat emptor - use at your own risk.

[efusco]

<div class='quotetop'>QUOTE(Stocky\";p=\"71091)</div>

I never said that it was good for gas or the emissions.  I just said that if you get into a bind with your NiMH battery going flat when climbing hills or whatever, then this will get you out of it.[/b]

Actually, you said nothing of the sort...you didn't say anything about the utility except about concern by posters on other forums of the 'battery going flat'. Anyway, there 'may' be some utility in getting over a particularly steep 'hump' on a climb if the battery is really drained, but those times, I assure you, will be very very rare...maybe while climbing Pike's Peak or something.

The Toyota dealer told me that the car DOES go into a special mode, he specifically called it \"fast charging mode\".  However, someone with the set of manuals may be able to post a confirmation or rebuttal.

He made that up. Others with battery monitoring equipment can rebutt that, but I assure you it isn't true.

When I took delivery of my Prius this afternoon (WUHU), I spoke with the Toyota Service Manager.  He confirmed that it is the way the service guys charge the battery when they have problems.  Go figure.

Yea, ok, so maybe they left the car in neutral for a long time and it got down low and they have more work to do on the car in that state so they rev it up to get the SOC back up so they can continue their work. This is still not something routine or something the lay person should need to do or worry about....if the SOC is low just drive your car.