charging procedure for 12 volt battery

[priusunum]

I just bought a Schumacher battery charger as a precaution in case I ever run down the 12 volt battery on my 06 Prius.
It has settings for using 2amps/30amps and 60amps for charging. I believe I should use only the 2amp setting for the Prius battery for slow, safe charging.
My question is, when I'm connecting the charger to the special positive post in the engine compartment, and of course also connecting the negative lead to the ground recommended in the manual, do I also need to disconnect the negative ground to the actual battery (that's located in the trunk area)?
One more question: Am I correct that I should never use the 60amp setting for jump starting? or is that ok, since it's for a short time?
Thanks to all those more knowledgeable than I who take the time to answer these type of questions! It's very helpful.

[DanMan32]

Never use anything but the 2A setting. Not much current needed to get the car started. I suppose for quick jumpstart to get the car turned on, the 30A setting should be OK, but not much longer than necessary to power up the car to READY.

If you were to disconnect the ground terminal at the battery, then the charger would be disconnected from the battery, which would be of no use to you. That's assuming you're connecting the charger at the jump terminals rather than directly to the battery.

[priusunum]

<div class='quotetop'>QUOTE(DanMan32 @ Dec 30 2006, 06:24 PM) [snapback]368712[/snapback]</div>

Never use anything but the 2A setting. Not much current needed to get the car started. I suppose for quick jumpstart to get the car turned on, the 30A setting should be OK, but not much longer than necessary to power up the car to READY.

If you were to disconnect the ground terminal at the battery, then the charger would be disconnected from the battery, which would be of no use to you. That's assuming you're connecting the charger at the jump terminals rather than directly to the battery.
[/b]

Thanks Dan. That's what I needed to know. I'm really enjoying my three-month old Prius! Happy New Year to all Prius Chat readers and writers.

[c4]

If you are using the front "jumper" terminals under the hood, do not disconnect anything.. If on the other hand, you are connecting directly to the battery terminals in the back of the vehicle, you *may* want to disconnect the ground lead from the vehicle if you are using a "smart charger".. The reason for this is that due to the parasitic drain of the vehicle's electronics, a smart charger will never sense the "battery full" condition as long as the vehicle electronics are drawing a bit of current; I've also seen some brands of "smart charger" go into an automatic desulfation mode because the drain fools the computer into thinking that the battery is not charging properly.. On the down side, by disconnecting the vehicle, you will lose all your clock/radio settings and your tank mileage readings. If you are using an old style "dumb" charger without CPU control and sensing, you can leave the battery connected to the vehicle without any issues.

It *is* possible to fast charge most lead acid batteries including the Prius battery, but the caveat is that faster charge rates typically result in much more gassing and electrolyte loss.. IF you have drained your battery, a quick blast at a higher rate shouldn't do any harm, but I would hesitate to go up to the 60A setting, which is usually designed to give a quick burst of current for conventional vehicle starters (on the "dumb" chargers I've taken apart, the "boost" setting normally just switches out the regulator and control circuit and typically results in an open-circuit voltage of well over 25V, which might be OK on a conventional vehicle, but not what I'd want to test on a Prius)..

[Walker1]

[quote=priusunum @ Dec 30 2006, 05:18 PM) [snapback]368710[/snapback]</div>

I just bought a Schumacher battery charger as a precaution in case I ever run down the 12 volt battery on my 06 Prius.
It has settings for using 2amps/30amps and 60amps for charging. I believe I should use only the 2amp setting for the Prius battery for slow, safe charging.
My question is, when I'm connecting the charger to the special positive post in the engine compartment, and of course also connecting the negative lead to the ground recommended in the manual, do I also need to disconnect the negative ground to the actual battery (that's located in the trunk area)?
One more question: Am I correct that I should never use the 60amp setting for jump starting? or is that ok, since it's for a short time?
Thanks to all those more knowledgeable than I who take the time to answer these type of questions! It's very helpful.
[/b]

I found that using a "battery tender" is the way to go. When the battery drops below 12 volts the tender puts in a nice trickle charge until the battery reahed its maximum. The key here is NOT to over charge the battery. I have 2 battery tenders and after 2 years neither of my vehicles has needed a new battery.I bought my tender] a Harley Davidson dlr. for $32.00. At that time the bike sat for some long periods and wouldn't even turn over. Now I have the battery tender am the bike's battery cranks over fast. use your discetion.

[jayman]

According to Toyota TSB PG007-03, you're supposed to use their fully automatic fancy-schmancy 10 amp charger, which is made by Associated. They don't recommend a 2amp charge due to the length of time it takes.

I got at auction/surplus a few VDC battery tenders very similar to this one:

http://www.vdcelectronics.com/batteryminder_12117.htm

I wouldn't pay $70 though.

You can't depend on the Prius to charge an almost dead 12 v battery, especialy in short trip operation. Properly charge it first.

[dmulvany]

<div class='quotetop'>QUOTE(jayman @ Jan 7 2007, 07:50 PM) [snapback]372251[/snapback]</div>

According to Toyota TSB PG007-03, you're supposed to use their fully automatic fancy-schmancy 10 amp charger, which is made by Associated. They don't recommend a 2amp charge due to the length of time it takes.

I got at auction/surplus a few VDC battery tenders very similar to this one:

http://www.vdcelectronics.com/batteryminder_12117.htm

I wouldn't pay $70 though.

You can't depend on the Prius to charge an almost dead 12 v battery, especialy in short trip operation. Properly charge it first.
[/b]

Jayman, is the TSB above available online? If so, could you let us know how to find it?

Do you disconnect your battery from the car when you use the BatteryMINDer Plus? Is it able to restore a dead battery? Mine definitely needs a therapeutic touch!

I'm interested in getting the BatteryMINDer Plus since I also need a battery charger for rechargeable batteries in a small boat, and this charger can apparently handle a variety of batteries. Got suggestions for where I can pick one up near Rockville, MD?


Dana Mulvany
dmulvany@usa.net








<div class='quotetop'>QUOTE(jayman @ Jan 7 2007, 07:50 PM) [snapback]372251[/snapback]</div>

According to Toyota TSB PG007-03, you're supposed to use their fully automatic fancy-schmancy 10 amp charger, which is made by Associated. They don't recommend a 2amp charge due to the length of time it takes.

I got at auction/surplus a few VDC battery tenders very similar to this one:

http://www.vdcelectronics.com/batteryminder_12117.htm

I wouldn't pay $70 though.

You can't depend on the Prius to charge an almost dead 12 v battery, especialy in short trip operation. Properly charge it first.
[/b]

By the way, it is quite ironic that Toyota has a TSB about a charger for the 12V battery. Just this past week, the service department charged my Classic Prius's weak Panasonic battery by running my car in place, and told me that there was absolutely no charger that Toyota recommended for charging my battery (I had asked about this beforehand). I was scolded by the service representative for not driving the car enough and was told in writing that I should drive my car thirty minutes every single day to keep the battery charged, even though they told me the battery was in good condition. (In fact, it lost over 0.4 volts in two days.) This battery is a Panasonic battery with standard posts mentioned in another TSB as a replacement for the original 12v battery and is less than a year old.

So I would really like to see and print out this TSB so I can show it to the local service department since they should have it on hand to charge Prii instead of merely running them in place for two hours!

Dana Mulvany
dmulvany@usa.net
Rockville MD

[jayman]

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 8 2007, 05:11 PM) [snapback]372705[/snapback]</div>

Jayman, is the TSB above available online? If so, could you let us know how to find it? [/b]

I'm sure I got it from this forum, but I'm too lazy to look it up. Here it is as downloaded, look for the Adobe pdf attached to this reply.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 8 2007, 05:11 PM) [snapback]372705[/snapback]</div>

Do you disconnect your battery from the car when you use the BatteryMINDer Plus? [/b]

Ok I went down to the parking garage and took these pictures. I worried the Prius alarm would go off if exposed to the desulfating pulse from the VDC unit, but a year later everything seems fine. You'll notice the inline 3 amp fuse to protect the battery. I took off the wire protection sleeve so you'd get a better idea of how the harness looks, it's just regular zip wire

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 8 2007, 05:11 PM) [snapback]372705[/snapback]</div>

Is it able to restore a dead battery?[/b]

No, it cannot charge a dead battery. Like most microprocesser controlled battery chargers, it will refuse to charge a "dead" battery, though some have a manual "defeat" button to force charging. You'll need a conventional charger at 10 amp rate to do that. Once the ammeter on the regular charger indicates a reasonably "full" charge, then you can use a desulfator to condition the battery.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 8 2007, 05:11 PM) [snapback]372705[/snapback]</div>

I'm interested in getting the BatteryMINDer Plus since I also need a battery charger for rechargeable batteries in a small boat, and this charger can apparently handle a variety of batteries. Got suggestions for where I can pick one up near Rockville, MD?[/b]

I got the earlier versions of my VDC at a local auction/surplus place for about $30 Cdn each. I'm not sure if I'd cough up $70 each for one. I'm under the assumption they do direct online order, otherwise try the usual "suspects" : NAPA, Pep Boys, etc.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 8 2007, 05:11 PM) [snapback]372705[/snapback]</div>

Just this past week, the service department charged my Classic Prius's weak Panasonic battery by running my car in place, and told me that there was absolutely no charger that Toyota recommended for charging my battery [/b]

Not sure about the Classic, but the TSB I attached is for the current Prius. If your Service Manager is that uptight, tell him to have a beer already! Geez!

[dmulvany]

<div class='quotetop'>QUOTE(jayman @ Jan 8 2007, 07:37 PM) [snapback]372783[/snapback]</div>

I'm sure I got it from this forum, but I'm too lazy to look it up. Here it is as downloaded, look for the Adobe pdf attached to this reply.
Ok I went down to the parking garage and took these pictures. I worried the Prius alarm would go off if exposed to the desulfating pulse from the VDC unit, but a year later everything seems fine. You'll notice the inline 3 amp fuse to protect the battery. I took off the wire protection sleeve so you'd get a better idea of how the harness looks, it's just regular zip wire
No, it cannot charge a dead battery. Like most microprocesser controlled battery chargers, it will refuse to charge a "dead" battery, though some have a manual "defeat" button to force charging. You'll need a conventional charger at 10 amp rate to do that. Once the ammeter on the regular charger indicates a reasonably "full" charge, then you can use a desulfator to condition the battery.
I got the earlier versions of my VDC at a local auction/surplus place for about $30 Cdn each. I'm not sure if I'd cough up $70 each for one. I'm under the assumption they do direct online order, otherwise try the usual "suspects" : NAPA, Pep Boys, etc.
Not sure about the Classic, but the TSB I attached is for the current Prius. If your Service Manager is that uptight, tell him to have a beer already! Geez!
[/b]

Thanks for the pictures, Jayman. Clearly your battery is different from mine (2002 Classic Prius).

I'm a bit confused about what to do after being told by my local service department last week to drive my 2002 Classic 30 minutes a day just to keep the battery charged, which is of course ecologically unsound, so I called Toyota Customer Experience today, and they're opening up a case. I did get told that apparently every time the 12 volt battery goes dead, owners are apparently supposed to bring it to the local service department to get charged, even though it was confirmed that Toyota does not recommend a charger for the battery, leaving the only approved way of charging the battery in the Classic Prius to be running the car in place for hours and hours (and the service department had returned the car to me with the battery charged only 50%----so what's the point?). I had never ever been told to bring the car in for charging by Toyota, which was aware that my battery had run down when I utilized the free Toyota roadside service to jump start the car at least once during the first three years I had the Prius.

I was told I should hear back from Toyota in a couple of days. Sat in my chilly car for a while running it in my garage today. Maybe I'll invite the local press to take pictures and show them my invoice from 355 Toyota telling me to run the car for 30 minutes every single day.


Dana

[jayman]

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 9 2007, 06:07 PM) [snapback]373324[/snapback]</div>

the only approved way of charging the battery in the Classic Prius to be running the car in place for hours and hours (and the service department had returned the car to me with the battery charged only 50%----so what's the point?). [/b]

Ok I'm confused now.

How did you determine your 12 vdc battery had 50% charge? Did you check the electrolyte?

If you're referring to the car display, that indicates the "charge" of the NiMH traction battery, and it's not an absolute scale of 0-100%. It represents about 40-80% which is the range Toyota allows on the NiMH battery.

It's perfectly normal for the NiMH battery pack to vary in charge from blue bars down to pink, up to green. You really have no control over it.

As far as the 12 vdc auxilary battery, the TSB provides specific instructions for charging. I'm I'm wrong about this, please correct ASAP