Battery Maintenance - Revive your Dead or Dying 12v Aux Battery

I've been having a really odd problem with my Prius starting, or holding charge maybe.
I'm not sure if it's the 12v battery or if it's the alternator. I just had both checked my a standard mechanic and they claimed both are fine.

Here's what's happening:
I have a very small collision that ended up taking my car to the body shop. When I got it back, unfixed,
the car battery was dead. I assumed they unhooked it, but I really don't know.

After a week I had it jumped and took it to my mechanic. they recharged the battery fully or so it seemed.
I made a habit of starting it once a day, but I can't drive it as it's not street legal yet. Twice now, I missed starting it one day
and the next day it was dead. It doesn't seem to be holding charge to start longer than 24hours after the battery seems to be
fully recharged. I talked the the toyota dealer, they suspected the 12v. i suspected the alternator, but after this once shops
says both are fine, I'm at a loss.

Any ideas? similar problems? i can't afford to pay a dealer to "$200 look at it".

t's a 2005 Prius, I'm unsure if the origianl battery 12v or not, as I bought it used 3 years ago.

 

there is no alternator. buy a digital multimeter. under the hood, inside the fuse box, there is a 12v jump point. it's in your owners manual. in the morning, before turning the car on, open the passenger door, crawl across the armrest and release the hood latch. don't use the drivers door, because it starts a bunch of things that reduce the battery voltage. put the red lead from the multimeter on the jump point, and the black lead to an unpainted bolt on the engine or chassis. if it measures less than 12.5 volts, buy a new battery. i believe you need a new battery. stay away from the guy who said the alternator is fine.

 

Most of Bisco's reply is spot on.

The simple answer is: The body shop "wounded" your old battery and what you are doing by starting it without driving is putting more nails in the coffin.

You WILL need a new 12 V battery before you put it back on the street and that will cost you about $200.
The new battery needs to be fully charged before use.

 

Words are important.
I said ***IF*** the voltage was at 14.5 when fully charged.

The rest of your post is just insulting, inflamatory BS and I refuse to be drawn into it.

I'm not making anything up. I've been in the Electronics industry probably longer than you have lived; maybe a LOT longer so I don't need any self-serving crap from you.

Have a nice day.

 

The combination of (likely) draining when the car was in the body shop, coupled with the car mainly sitting now, since it's not street legal, likely means you're going to need a new battery. Just starting the car up and running for a few minutes isn't enough to maintain it. You could remove it from the car, and perdiodically hook up to a smart charger. But with the battery being over 3 years old, and having taken a few knocks, I'd throw in the towel. Might as well wait 'till it is street legal.

 

Now the evidence points to outright lying. Nobody who really graduated from college with honors would make the grammatical errors that you have made AND would not say that they have "an electronic degree" because there is no such thing.

I know that you don't care.......or are too dense to understand but for others who might still be reading this thread:

A sealed battery is intended to NEVER be opened to add water.
If the water IS boiled out of the electrolyte solution, that is a SYMPTOM of a problem and not the cause.

Either there is a leak in the battery somewhere OR the charging system is not working right OR the battery has developed an internal fault that causes the charging system to charge too much.
Period, end of discussion.

The battery is designed to NOT boil off electrolyte.
The charging system is designed to NOT boil off electrolyte.
If the electrolyte IS disappearing, something is wrong and adding back water to the battery IS NOT THE FIX.

Done.
Further ranting will be ignored.

 

Sorry, I've been so busy with work and trying to get this fixed. To answer a few of these questions:

1.) Body Shop Time - was about 3 weeks - a month. I'm certain it was DEAD 90% of time while there, as after 3 days when I picked up my belongings from it from the lot, it was already dead. I asked why the car was dead and the person there said they probably disconnected it. I have no idea why and asked and he said he didn't know. When they towed it to my house, I insisted they make sure it was charged so that it could be locked. They agreed, but when the car was delivered, it was dead again. The tow driver had to jump it to get it into neutral.

2.) The reason it isn't currently street legal is that is is missing the left headlamp and bumper. The fender also needs replacing. Basically it was considered a TOTAL but only based off body work. I was informed there was no mechanical damage. As the small impact hit the front right side of the car very low.

3.) It's true I don't drive it every day. I try starting it every day for at least 15 - 30 minutes and sometimes when I have time and it's night, I drive around in a circle around my house avoiding the police for maybe 5 - 10 minutes to charge it up. But it doesn't seem to matter, if it's not started at least ONCE every 24 hours, it dies.

4.) I have bought a battery 12v and it's ready, but I'm starting to worry it could be another or bigger probably. I'm concerned that it could be the hybrid battery and one or another mechanic not knowing what they were doing did something incorrectly. to damage the electrical system. I just don't know.

5.) When I run the dash test, ala lights 3 times, it always read the voltage over 14.0 I assumed this was the reading of the hybrid batter?

And I know everyone keeps telling me to buy a reader, buy a charger, but I really CAN'T afford it at all, I'm buying everything to fix on this Prius myself out of pocket, as the insurance barely gave me anything for it even with full coverage. In addition, things just aren't financially solid at the moment and overall without this unexpected battery/starting issue, it's costing me 2,000 - $5,000 in body work.

I feel like I should be able to just to go to a mechanic and them tell me whats wrong, but it seems I need a Prius specialist?

 

Oh, Oh Oh, 1 thing I forgot to mention. the impact pushed the passenger side door back just a little but, so it's not lining up quite perfectly a little off. The door signal normally thinks it open unless I give it a good hip check fonzi shut, then the car's locking system with lock. I'd imagine if it locks then the door wouldn't be telling the car it's OPEN? Could it be faulty and the door be causing it to drain?

 

you need someone with a toyota specific reader. if you can't find anyone, you will have to go to a dealer.

 

try avi's automotive, he's a helpful member here.

 

I'm hoping that NON dealerships have this reader? Any easy was to search for a location that possesses this? I'm located in South Los Angeles.

 

are you near avi's automotive? i can't think of a way unless they advertise toyota repair.

 

Avi's is about 45m - 1 hour from me. But getting my car there wouldn't be possible until I had the frame fixed. so that's down the road.

 

judging from this post, it's your 12 volt. you need to disconnect the negative battery cable in between use until you're back on the road again.

 

he's a good guy. you may want to call and run things by him for advice.

 

Several years ago for fun, I also removed the top label on the 12V GS Yuasa battery that was standard equipment on my 2001, when I replaced it with a larger Panasonic battery. As you pointed out there is no issue removing the rectangular plastic cover over the six vents, or the rubber caps over the vents themselves.

When I removed the caps, I noticed that the lead plates were separated by the white fuzzy mats which AGM batteries have. When you looked into your battery, did you see those white mats or just the grey lead plates?

If you just saw the grey lead plates then it was very appropriate to cover the plates with distilled water.

If you saw the white fuzzy mats, then I personally would have been content just adding a couple of ounces of water to each of the six cells. The idea is not to drown the AGM battery cells in water.

I think it is great that you are trying to extend the life of your 12V battery. However, 12.2V is not very high (compared to a new, fully-charged 12V AGM battery which will measure 13.0V out of the box, open-circuit). Have you tried putting your battery on a 4A charger overnight to see if you can bring the battery charge to a higher level?