Battery dead yet again...

A couple of thoughts (ok ended up being more than a couple..):

1) sorry that people are having trouble with dead batteries, that is a drag.

2) Be careful about charging the battery yourself. As a general rule, most 12V chargers have too high a finishing voltage for sealed AGM type batteries. In flooded batteries it can be helpful to overcharge to balance cells and make sure the battery is really full. This may boil off some water, but since you can replace the water, no big deal. In a sealed battery this loss creates a permanent reduction in life expectancy and capacity. Ideally you should only use a charger/maintainer that is clearly marked as safe for sealed, Gel or AGM type batteries.

3) Owners manual does seem to say 3.5A max charge rate.

4) Do you really need to remove the battery to charge? With the car off, I wouldn't see why you couldn't just charge though the aux port under the hood. Even if there is a small drain, it should be trivial compared to your charger current.

5) Pretty sure Prius does not tell you when aux battery is failing. Dealer is probably confused, there is a hybrid battery warning light, and a standard battery warning light but this tells you that the battery is discharging. This indicates a failure of ths dc:dc converter (like an alternator failure) not the battery itself.

6) I am afraid this kind of service has nothing to do with toyota, or even the prius. It sadly just the way a lot of dealers do business these days. We had a ford with a bad alternator a few years back. Brought it in after just making it home on battery, and having recharged the battery. Told them the alternator was going. They said there's nothing wrong with it. Drove it home, died again. Had it towed in dead. They said your battery is dead. We charged it up and everything is fine, but you should get a new battery. Drove it around died again. Had it towed in, they said your battery is bad, you have to replace it. We paid for a new battery. Drove the car around and it died again. Had it towed in, they replaced the alternator, and all was fine. The dealer picked up the tow and alternator under warranty, but we were stuck with the $100 battery and the inconvenience of being stranded three times. All could have been avoided if the service dept in question 1) listened to what their customers actually say 2) actually bothered to check things out, not just plug it into a computer.

7) As has been mentioned many times, you have to be more careful with this issue on a Prius. Since the 12V battery does not have to supply the current to actually start the car (HV battery does that) the Prius uses a much smaller battery than most cars do. It is entirely plausible that some folks really have a battery that is defective, or was abused at the dealership while on display, or may have a dc:dc converter that is not putting out enough voltage to really put a good charge on battery. The vast majority though, are just simple human errors that we all are susceptible to making. There are things you can do (like always locking, turning off headlights manually, turning off SKS on long term parking) to reduce the probability of making those errors.

8) If all else fails, perhaps we should be looking into either manual or automatic battery disconnects to keep this sort of thing from happening. It would be interesting to know if anyone has tried something like this on a Prius?
PriorityStart! - Stop Manage Dead Batteries - Standard Model

Rob

 

Thats a great find! Optimas are awesome batteries. Combine one of these with an auto disconnect and you'd probably never need another battery or jump again

Interesting notes on the battery self test there too!

Rob

 

The Prius battery really isn't sealed. Whenever I remove mine, I can quite clearly see the electolyte sloshing around, and if I give it a shake, can hear the liquid gurgling inside too. There is a sort of urban legend about the battery being some sort of special gel cell but it really does have free electrolyte

A good automatic battery charger should be able to properly charge the tiny 12 vdc battery. Since the new forum software a couple of months ago I'm unable to post pdf's.

According to the PRius PDF, they recommend removing the 12 vdc battery from the vehicle. THeir automatic battery charger is made by Associated. They specifically state in the pdf to not use a 2 amp charge, due to the "prolonged charge time."

Given that Parky has a completely dead Prius and would need to crawl into the hatch area to even open the hatch, it would be best for him to either boost the Prius or to attempt to charge it using the underhood jump point

Due to the constant voltage source, once the 12 vdc battery is chronically undercharged or discharged, one cannot expect the Prius itself to properly recharge the battery. It's best to just go through the hassle of removing it and properly charging it

If one doesn not want to go through the hassle of removing the battery, I suppose it wouldn't hurt to just hook an automatic battery charger directly to the battery and charge it overnight.

In bitter cold temps, you do far more damage to a battery having it discharged, than an aggressive charging

 

Further on the Prius battery, the TSB also states the correct test procedure. If the car has been just charged or driven, they recommend turning the headlights on for 60 secs.

Then wait 60 secs

Then use a DMM to directly measure the voltage at the battery. It should be 12.8 vdc. Anything less indicates the battery needs recharging

 

I almost got the Optima 51R, but hesitated when I read this:
Honda-Tech.com: Acura Integra: ATTN Optima 51R Yellow top owners!

So then... has anybody used the stinger battery mentioned earlier in the thread:
Stinger SPV35 Deep Cycle Car Audio Battery Honda Acura

Due to the reported problems with the 51R?

This shouldn't be rocket science!

 

Dead battery here. Waiting for roadside assitance. If they can get it started, is there anything I should do to avoid draining the battery again right away? In other words, do I need to make sure it is fully charged? Will I need to take it in for service? My car is 2.5 weeks old.

 

He got it started. I guess I'll go on a long drive now.

 

Geez, I pack up the cats and drive from the hobby farm back to my house, and we have more reports of kaput batteries. It really caught my attention when you mentioned you have had your Prius for only 2.5 weeks

The new forum software won't let me post pdf's anymore, but if you have a disposable address like a Yahoo or MSN, PM me and I will send the Toyota Prius PDI (Pre Delivery Inspection)

The PDI is pretty emphatic to remove the 12 vdc battery and FULLY charge it before delivery to the customer. The PDI has the dealer using their fancy schmancy Toyota Automatic Battery Charger set at 10 amp position.

The charger is made by Associated. Any good automatic battery charger will work

If you have experienced bitter cold temps and have to park outside, I'm afraid a long drive won't do it. I would insist the dealer correctly follow the PDI and fully charge the 12 vdc battery. Otherwise it will leave you stranded again

 

I would settle for a charge system that ramped up the voltage in extremely cold weather. You might be an exception, most of the dead battery reports have occured in bitter cold temps, say -20 F

 

Bitter cold - check.
Park outside - no, I park in a garage (unheated). Stayed home on the coldest days. Today it was finally above freezing.

Car was fine Friday. Didn't use it Saturday. Was dead today when I went out to the garage.

My best theory is that I left a map light on (?) or something.

You have me worried enough that I will call the dealer tomorrow. I can't imagine that they would miss something that important from the PDI. They sell a lot of Priuses (#1 in midwest), but I'll check with them anyway.

 

I live in Milwaukee and have to keep mine outside, but I went ahead and bought a jump charger that was recommended in one of the threads (just in case). Granted, I'm really careful about leaving stuff on, but you never know. Mine is closing in on two weeks, so I hope I don't have a similar problem...

 

There has to be something wrong with the car or you have something left on. I would get it checked out at a dealership. I have had no problems with mine and have owned it for 3 weeks or so. It has sat outside during the extreme cold at work, and is just fine. You could have a defective battery or not enought electrolyte in it. I live in Madison let me know if I can help.

 

Let's see if I can post a PDF. Yes. Here it is. Click on the "Manage Attachments" button and you can post a PDF.

 

Weird, I tried around 1-2 weeks ago and when I did the Manage Attachments thing, there was a dash next to pdf. I'll try again

 

Ok, this is the PDI - Pre Delivery Inspection - for the Prius

 

Danny's constantly making improvements.

 

Cool. I've left a message with the dealer.

 

For the most part, I have to agree with that. It wouldn't have cost Toyota any more money to put a normal size/capacity battery in the Prius that would be far more tolerant of abuse

If you had battery issues in sunny, funny California, imagine an area that can dip down to -40. I had trouble my first winter just driving around in those conditions, the fixed voltage charge source couldn't keep up with demand (Headlights, Max Heat, constant electric rear defrost, etc)