Replacement of 12 volt auxiliary battery

JimboK - plan on at least 24 - 48 hours for a smaqll battery to be fully charged by a trickle charger. Even when it gets to full voltage, it digests the charge for a while and will go up and down a little. After 48 hours, if it is not good, it's not good.

 

I just had an Optima installed, with fgoodyear doing most of the work. I had run my old battery down several times by leaving sound and lights on at car shows, and forgetting to leave the car running, too. It stopped keeping a charge for more than a few days as winter got colder, and I was driving less.

The install was mildly difficult. The instructions the eLearn sent were confusing, as they were apparently for the smaller (non-SmartKey) battery. The brackets were different, and many instructions did not apply. They start of by saying the model D51 will not work. The battery I got was model 51, no bloody A,B,C, or D. It installed fine. The instructions for the vent tube put it on the negative end of the battery which it will not reach. Etc.

Hobbit's instructions were right on the mark. I was glad I had read them. Removing the brake controller and HV battery vent duct helped ease things considerably. I used a jumpstart battery on the terminals under the hood to keep 12V in the system, so I lost none of my settings.

Now a question: Does anyone know if the Optima battery is less sensitive to the effects of complete discharges? I do my best not to let this happen, but I still sometimes forget, and drain the battery completely.

 

The website for that product says the maximum available charging current is 1.33A when the battery is fully discharged. At 12.1V, your battery is probably 75% discharged or more.

Here's my rough calculation: assume your battery has 35Ah capacity, so you need to replenish 26Ah. This will take at least 20 hours. Then I'd double that time because of inefficiency and because the charging current will diminish as the battery charge level comes up.

Bottom line, I suggest that you leave the battery connected to BatteryMinder for two full days before you decide it is ready to be installed.

 

If your question is Optima vs. the original equipment battery, since both are AGM I see no reason why Optima should be better (once you discount the marketing hype).

So it would be well for you not to allow the battery to become drained, if you desire long battery life.

 

I got mine from elearnaid. I hope i didn't buy it out from under your nose.

It's always best to avoid deep discharging, but the Optima is specifically a deep discharge rated battery, while the OEM is not. The Optima has different metal ratios, and also different plate geometry internally, so there will be some small difference at least.


BTW, I asked my wife to run the car overnight. I hope to hear from her today on how it's doing, but we really won't know until Tuesday or so if the battery is now charged.

 

Ahh, so YOU'RE the one!

 

Come on! Don't stir with the gas emitted! The gas is only hydrogen and oxygen. While hydrogen is not poisonous and is not absorbed, oxygen is just what you are breathing for. And realize how leaky your car is when following a smoke belcher and how little gas the battery emits: the maintenance-free battery never need a sip of water for a 5-year life? Although I won't suggest that you ducktape the bat vent tube to your nostrils ...

 

Update on my issue: My wife only could charge it for a few hours, and it was dead again in the morning. She dropped it Wednesday at the dealership in west Madison. The charged the battery, which passes load testing (it had better, it's only weeks old), and traced the problem to excessive current draw through the dome fuse.

Then they narrowed it down past the dome fuse to the stereo (Head unit, not amplifier, I think). The lights on the stereo buttons were not turning off!

They quoted $475 for the parts, and I told them about my extended warranty, so now they are covering it. They should get the parts tomorrow, and we'll get the car back. I'm really looking forward to getting a bit better mileage, especially if the battery is not always in need of recharge .

Thanks for the help and for the info on the forum in general. It's nice to know what normal current draw is on the battery, and other such tech info.








(Sorry for hijacking the topic)

 

Woo hoo! Now you're only down by about half on the extended warranty :_>

 

If there is no problem, then there will be no problem; but if there is a problem, then there will be a problem: acid will be spewed inside the car, or an explosive gas mixture will be released inside the car. Defeat the vent tube at your peril.

 

My wife's 2004 Prius was completely dead two weeks ago (no lights, doors wouldn't unlock) and had to be jumped, then yesterday didn't start after a 15 minute drive (though the electronics were all active) and had to be jumped. The good news for those in Silicon Valley, Yarnell's in Mountain View put in a new OEM unit for $138 plus tax (apparently they only charged for the battery, not labor).

Question:

- Is there a way for me to check the voltage level via the nav screen? Or can I use my $20 multimeter? If so, am I just checking voltage across the terminals with the car off, and can I do this from the jump location in the hood (between positive terminal and the body)? What should the voltage be?

Thanks!

Bill

 

Checking 12v Battery Health - Hybrid Car Forums

Tom

 

I have one that is out of a 2005 prius that I replaced with optima yellow top simply because I needed more battery as I installed an electric lift for a wheel chair/ I would like to have $35.00 for it . The negative cable is with it. It holds over 12.33 volts while out of the car for days.It looks like new I believe it was replaced in the car before I bought it. Never had problem with it . Just needed more battery

 

Just replaced my 04 accessory battery at 55,000 miles (6 years old). It was discharging after sitting for a few days and the car wouldn't start. It did this three times in two weeks so I wised up and bought an Optima D-51 deep cycle battery locally. I used a bench grinder to alter standard battery cable ends to fit the old cables. Also, I used the grinder to lessen the diameter of the stock battery vent connector to fit in the smaller hole of the optima. I used gasket sealer to plug the vent hole on the other side of the optima. Works like a charm all for $144 from Advanced Auto parts. Bought online for a 15% discount on the battery (or any parts) and picked it up at the store.

 

Yes
Partly; also do it in ACC
Yes
12.4 to 12.8V with the car OFF, not much less than 12.0V in ACC. Less than that -> dying battery. More than that -> car is ON or in IG-ON, or there is a serious charging system fault.

Leave the car OFF for a few hours before measurement so that any misleading "surface charge" in the battery will have dissipated.

 

Does anyone know how long the warranty on these 12 volt auxiliary batteries is? Mine was replaced two years ago and now they are telling me it is bad again.

I have a Prius Classic

 

< Never-mind! Found answer.. It is Not..>

Greetings!

Perhaps this is the dumb question of the day, but does anyone know, for sure, if the 12V OEM battery is covered by the extended warranty (the one referred through PriusChat) ??

TIA!

 

Napa has a $20 mail in rebate on the optima batteries.

 

My Gen II 2005 Prius has a new Optima 12 volt aux battery from eLearnAid. The battery was easy to replace with the included instructions. I will admit that I changed out the 12 volt battery way ahead of time because I just did not want to take chances provoking a well known Achilles heel in the Prius. I still have the original 12 volt battery that is in use as a starter battery for my Honda Eu3000i generator. Each time I have changed out the battery, I have kept them and use them for amateur radio disaster readiness. The last California earthquake shakeout drill was on 10/21. The little batteries were in use in the generator and in my ham radio station on the air with battery power. I keep the batteries instead of exchanging them for the small core fee. Hopefully I will get 5 years of use out of the new Optima D51. It will be in use in the car since I just added a ham radio to the rear of the car. So far so good. A small jump battery was in use during the exchange to preserve the radio settings. I do believe I may actually be getting slightly better mileage with the bigger 12 volt battery. Maybe its the increased tire pressures of 40psi and 0-20w Mobil 1 oil in use that keeps me in the average range of 48-50 mpg, both city and highway averaged together. Not a scientific calculation by any means, but just a good average on average.