charging procedure for 12 volt battery

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.

 

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)..

 

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.

 

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

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
[email protected]








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

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
[email protected]
Rockville MD

 

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

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

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>

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 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>

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!

 

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

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. h34r:


Dana

 

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

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

 

<div class='quotetop'>QUOTE(jayman @ Jan 9 2007, 06:44 PM) [snapback]373340[/snapback]</div>

The service department had a printout showing that the 12V battery of my Prius was charged 50%, and also that the battery was in "good condition" (although it clearly is not since it can't hold a charge). I don't know what kind of equipment they used.

The TSB you provided does not apply to the 2002 Classic Prius, which is the kind that I have. It only applies to the '04 and '05 Prii, and the batteries are visibly different, so I would not feel comfortable generalizing from that TSB to older Prii. Any idea whether there is a similar TSB for the older Prius models (the Classic Prii)?



Dana
Rockville, MD

 

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 10 2007, 02:11 AM) [snapback]373504[/snapback]</div>

Probably a standard 12 vdc battery "load tester" that uses a carbon pile - a resistance - to apply a heavy load to the battery. Ironically this will further discharge the battery! The load tester has two clamps that look like jumper cables, you attach them to the battery posts. The fancier ones have an electronic display and you press a button to run the test.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 10 2007, 02:11 AM) [snapback]373504[/snapback]</div>

Whoops I missed that critical detail. Unless a foum member is nice enough to dig it up, all I can suggest is purchasing a 24 hour subscription from Toyota's Tech Info resource center:

http://techinfo.toyota.com

You have to click on "Subscribe" and follow the prompts. The manuals are in Adobe pdf files. A 24 hour subscription should give you enough time to search for and download 2002 Prius "Pre Delivery Inspection/PDI" and "Auxilary battery" information.

At the very least you can't keep driving around with the 12 vdc auxilary battery in such a deeply discharged state, you will almost certainly damage it. If your owner manual provides this information, see if you can remove the battery altogether, and hook it up to a conventional battery charger at 10 amps for 3-4 hours.

It's asinine for the service manager to suggest you have to have the car "on" every day for their suggested period. Which BTW would not be enough to charge a severely discharged battery anyway. What happens if you go away for a week on vacation? Buy a new battery when you get back??

 

The Toyota Service Bulleting (TSB) about "Maintenance for HV & Auxiliary Batteries at Port & Dealers" for 2001-2003 Prii is available at the files section of http://autos.groups.yahoo.com/group/toyota-prius-sat1/. It looks similar to the one for newer Prii.

Anyone know if having the Panasonic 12v replacement battery (with the higher CCA and standard posts that was specified in another TSB) would make a difference with respect to this TSB? For example, there are Special Service Tools (SSTs), and I wonder whether there would be a compatibility problem:

Prius automatic charger, P/N 00002-YA122-01 (replaces 00002-YA121-01)
Toyota Diagnostic Tester Kit P/N 01002593-005
12 Megabyte Diagnostic Tester Program card
Midtronics Battery Tester

Interestingly, the previous version of the Prius charger is supposed to be set on the 10 Amp position, and charging in the 2 Amp position is not recommended due to prolonged charge time. The newer version appears to be more automatic. Some people have said not to charge the battery at more than 3.5 amps; I wonder what the newer version's maximum charge is.

The Prius Automatic Charger is *not* listed as an essential SST, so perhaps not all service departments don't have it (like my local Toyota service department which simply ran my car in place for 2 hours and didn't even charge the battery enough).

There's also a note that the Prius auxiliary battery is a special Valve Regulated Absorbed Glass Mat (AGM)) design and should NEVER be replaced with a conventional battery design.

There's a method for "Onboard Equalizing Charge of HV Battery." That requires the use of the Diagnostic Tester with program card version 10.1a or later, and the procedure takes approximately 30 minutes.

One thing that troubles me is that there is no explicit guidance for when to do the equalizing charge after the car has first been delivered to customers. Thus it's not clear whether service departments are supposed to do the "Onboard Equalizing Charge" if the 12V battery has been having problems.

 

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

I agree

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

Shouldn't be, though mostly it would depend on physical dimensions. As long as the battery is "safe" for use inside the car (Vented to outside) it should be fine.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

This is the fancy-schmancy automatic battery charger made by Associated I refered to earlier, with a 10 amp charge rate. Any good automatic battery charger can be used to do this

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

The dealer scan tool

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

Looks similar to this battery tester from Midtronics, which has the built in printer to spit out the claim your battery is "good" and "50% charged" which should be taken with at least a grain of salt.

http://www.midtronics.com/main.php?Categor...amp;recordID=88

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

Well, if the battery truly is at a 50% charge like the printout claims it is, you'd wait a day or more for a 2amp charge to do anything. Assuming it could even charge at all at a 2amp rate. I've had totally dead batteries on other equipment that needed 20-30 amps to even start charging.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 15 2007, 02:47 PM) [snapback]375962[/snapback]</div>

As I read it, the NiMH equalizing charge is for the HV NiMH battery pack. Not to do with the auxilary 12 vdc battery

 

Additionally, just because you set the 10A rate on the charger doesn't mean it's spitting out 10A all the time.. Even with an old "dumb" charger, if the battery were very low, you might get the 10A rate for the first 10-15 minutes or so, and then the charge rate would steadily decline as the battery neared full capacity.. If the battery already had a fair charge, it may start at less than 2A, despite your "10A" switch setting..

Things are a bit different with a "smart" charger- these typically pulse-charge the battery- with these chargers, you may actually get 10A, but only for short periods (ie, they'll measure the battery first, calculate how much charge is left, then send a 10A pulse that lasts a fraction of a second to a few seconds long, depending on how depleted the battery is, then stop, allow the battery to assimilate the charge, then measure and repeat the pulse again, etc, etc).. This pulse behaviour ensures that the battery is never damaged regardless of the charge rate, and the pulses help to break up sulfation and help charge the battery to a "fuller" state than the old "dumb" chargers can.. The other nice thing about most "smart" chargers is that once they detect that the battery is full, they'll automatically switch into a battery maintainer mode, where they'll just monitor the voltage and only send brief, low current pulses to maintain the battery when the voltage falls below a preset threshold, so you can actually leave these chargers connected without risk of damage to the battery..

 

<div class='quotetop'>QUOTE(jayman @ Jan 15 2007, 07:25 PM) [snapback]376089[/snapback]</div>

I had my battery tested yesterday by the Toyota-approved Midtronics at a different service department (and was provided a copy of the readout.) This readout was different from what the other service department had shown me, and it showed that my battery's state of health was zero. So the first service department had not used the correct battery tester for my 12 volt despite a TSB on what equipment to use for the Prius; that readout was using black squares instead of the graph that the Midtronics tester used. I figure that my Prius was never checked out by a Prius-certified technican at the first service department, but I was told that a Prius-certified technician was specifically asked to inspect my 12 volt battery at the second service department. So if anyone here sees black squares on the readout for a test of their 12 volt battery, the service department did not follow Toyota guidelines and used the wrong tester.

<div class='quotetop'>QUOTE(jayman @ Jan 15 2007, 07:25 PM) [snapback]376089[/snapback]</div>

For what it's worth, the battery was measured at 40% yesterday. Interestingly, despite having a zero state of health, it still was able to start up after being run for a while. I'll be getting the battery replaced, of course.

<div class='quotetop'>QUOTE(jayman @ Jan 15 2007, 07:25 PM) [snapback]376089[/snapback]</div>

You're right, but if there's a bad auxiliary 12 volt battery, I was wondering if this could affect the state of health of the NIMH battery pack, and if it would be a good idea to ask for the HV NIMh battery to be checked out, even though I'm not getting any direct indications that there's a problem. But perhaps the NIMh battery is not affected by the auxiliary battery?


So what do you all think of a Toyota service department using the wrong battery tester on a Prius despite a TSB providing guidance about the correct SSTs, claiming my battery was in good condition despite being told it had died three times in four days and that it had been driven on the interstate for two hours, charging the battery by merely running it in place despite the availability of a Prius automatic charger, releasing the car with a 50% charged battery, and telling me to drive the car for 30 minutes every day to keep the battery charged up? Not that it should make any difference to how a Prius is treated, but I'm a female with a severe disability (hearing loss), and if I get stranded on the road, I'm more at risk because I have trouble hearing on the phone and can't hear a lot of sounds (I'm deaf at the middle and high frequencies). Somehow, it feels particularly callous when a Toyota service department dismisses the potential problems of a bad battery for a driver with a known disability.

Dana

 

<div class='quotetop'>QUOTE(c4 @ Jan 16 2007, 11:04 AM) [snapback]376247[/snapback]</div>

Good point, glad you brought that up.

Remember with the old chargers, you'd watch the needle and with the battery fairly discharged it would start out around 10 amps. Come back in an hour or so it would be hovering around 5-6 amps, and a few hours later either be on 2 or on the "0" peg?

 

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

Uh oh

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

Sounds like the sort of gadget Canadian Tire - or as we call them Crappy Tire - uses to "prove" their wonderful Motormaster Eliminator battey is in fine shape, and the car in question needs a new alternator etc etc. When point of fact, their crap battery has a bad cell and Crappy Tire had a real payday replacing a bunch of unnecessary parts. Avoid them like the clap.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

A damaged or very discharged 12 vdc battery will hang in for the Prius a lot longer, since it doesn't have a huge current draw cranking over a motor. It just has to run the brake boost and coolant pumps, and only needs to hang around long enough for the HV relay to close, then the inverter/converter can take over the load.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

Beats me and I'll readily admit it. Suppose it wouldn't hurt to ask, but whatever you do stay far FAR away from that first dealer. See my metaphor related to the Clap.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

I think that stealership should be closed ASAP, and all the employees shipped off to a desolate island in the Marshalls that used to be used for atmospheric nuclear testing, so they could stay alive by cannibalism. Furthermore, Toyota Inc owes you a big apology and perhaps a shiny new car. You know, discrimination and lawsuits and rather expensive negative publicity...

Nudge nudge wink wink say no more say no more

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

Wanna bet? I've noticed the service writers automatically treat women differently then men. If the female customer is wearing tight jeans, and has enormous mammary glands, they treat her differently again. Of course in either case they treat the woman like complete crap, lots of insincere "concern" – usually about the size of said mammary gland(s), condescending nothing-talk, etc.

<div class='quotetop'>QUOTE(Dana 2002 @ Jan 16 2007, 11:51 AM) [snapback]376278[/snapback]</div>

Well, I'm built like a bouncer and I have a temper, so I'd love to meet those characters. Perhaps a wee bit of attitude "adjustment" would work wonders for them.

I hate to say it, but let's be quite frank about this for a moment: persons with physical disabilities are treated like s*** in our society. There are a lot of greasy, slimy, scrawny little dickheads out there who appear to go out of their way to really torment and/or rip off persons with disabilities, and it starts at a very young age.

Just last week, I was at a local mall and I caught a couple of young boys teasing a girl with cerebral palsy. So I lightly smacked both of them, not hard enough to really hurt them, but hard enough they got the message.

I also hate to say this, but imagine if you need repairs or a renovation done to your home. The plumber/electrician/contractor will treat you like crap. Beware. But if those characters encounter somebody like me, for some odd reason they are *very* careful how they treat me. Maybe afraid of a good thumping??

Ok I'm getting off my soapbox and the rant is over. I just get *really* steamed when I hear of this sort of bulls***

 

<div class='quotetop'>QUOTE(DanMan32 @ Dec 30 2006, 02:24 PM) [snapback]368712[/snapback]</div>

I had an interesting experience when trying to charge a dead 12V on a 2004. First I hooked up a brand new high-end battery tender to the special (red) terminal under the hood & minus to the chassis stud, and it appeared to be functioning normally for about 5 minutes, then the charger (tender) went dead and was completely non-functional. Then I took a 10 amp current-limiting lab supply and hooked that up the same way. With the current limited to 4A, the supply limited at 5 volts and would not rise, even after an hour or more. Current limiting at 10A caused the instrument cluster to flash and kicked in an "engine malfunction" error, still with the voltage limiting at 5V at this current. Jumpstarting with an ordinary car battery brought the system up and working properly, however.

Later I discovered some interesting things when examining the battery current while the car is not operating. When the trunk lid is down but not fully latched (but unable to raise it since it is partially latched), the battery current is over 2 amps when the rear dome light is on (in response to the trunk lid), but even when the lamp is switched off, the current remains high at nearly 1 amp. It's clear from this that the battery would be exhausted rather quickly if the trunk lid was not firmly slammed down, and there could be no indication to the user that this was happening. With the trunk lid down securely the current remained at about 1 amp for a couple minutes, then fell in two steps to only about 20 mA or a little less. At this low standby current the battery should be good for at least a month or more.

I probably replaced the 12V battery needlessly, and simply need to be a bit more aggressive when closing the trunk lid. Has anyone else had a similar experience?

 

<div class='quotetop'>QUOTE(RogM @ Jun 14 2007, 12:14 AM) [snapback]461347[/snapback]</div>

I've had similar experiences with dead batteries. I have a commecial battery charger, the kind on wheels, at the hobby farm. I picked it up at an auction. Before I started leaving the Battery Minder plugged into my tractor, the battery went completely flat a couple of times. Turned out a bad switch for the rear work lights was causing a drain.

I had to set my commercial charger to 30 amps, and once even to 60 amps, before the battery even wanted to take a charge. I got a new battery after that, and now leave the negative cable off whenever I'm not using it, with the Battery Minder always hooked up.

Remember that Toyota in the PDI/TSB recommends their fancy-schmancy 10 A automatic charger, branded "Toyota" but made by Associated.

<div class='quotetop'>QUOTE(RogM @ Jun 14 2007, 12:14 AM) [snapback]461347[/snapback]</div>

A few of us have been tricked by the rear hatch. I now have the habit of giving it a firm slam.

Hopefully sometime this summer I can "borrow" the expensive AEMC power quality meter from the office, and hook it up to the 12 vdc battery. I intend to not plug in the battery minder for a week or so, and let the AEMC record current and voltage over that period. Not only am I curious about normal standby drain, but I wonder how often the brake boost pump decides to run when nobody is around.