Dead 12V Battery/Rhythmic Clicking & Beeping

Would you agree though, that CCA (or CA) is a decent measure of a battery's health? In other words, a high CCA spec might not be needed, but whatever the spec, if the measured CCA (measured with an electronic load tester) is higher than spec, that battery is more viable than one where the measured CCA has dropped lower than spec?

 

Yes.

CCA and AmpHour go hand in hand; a different way of measuring output, and each has different meaning. Kinda like engine output that is measure in horsepower and torque. Each value has a different meaning and significance.

Most of us are used to CCA b/c of decades of conventional cars w/ 12V starters; the higher the CCA, the better, generally speaking. With hybrids like the Prius, CCA is not meaningful, b/c they don't face that short burst of high amperage demand from a 12V starter and ignition system requirements. The Prius faces a steady, lower amperage drain.

The one drawback with load testers at autoparts stores is the load they place on a Prius AGM battery is might be too large of a load. An otherwise healthy/good Prius 12V AGM battery might show-up as being "bad," when it is not.

Optima Yellowtop for Prius; Product Finder | OPTIMA Batteries
CCA=450Amp, 38AmpHour
Toyota True Start (see picture from post 20): CCA=325Amp, 45AmpHr
DIFFERENCE: 75Amp and 7AmpHour

 

The ignore user function is a fantastic feature of Prius Chat.

I only have one member on there since December 4, 2016.

 

Nope. You got that one wrong too.

I only "attack" you because you persist in making absolute calls where there is ABSOLUTELY not enough information to rule out all of the other possible causes.

You have the absolute power to fix that by rewording your suggestions.

 

I've figured out a couple of things over the decades regarding all types of batteries, and recently, AGM types.

1) For me, the maximum # of times an OEM Prius battery can be completely discharged is around 10-15 (give or take a couple, since I wasn't keeping a written record). An automatic charger will usually not even attempt to charge such a battery, but a manual one can; I kept it safe and did this with the battery removed. Leaving the push-button interior light on is what ran my battery down all those times-live and learn (where's the timer on these lights?)! Also, the more "charge/discharge" cycles a battery undergoes (esp. a starting battery for non-hybrid vehicles), the less time it will last (due to plate shedding). We had a "hard to start" 1968 Ford LTD wagon when I was a kid; there were times when the battery was quite depleted before that huge 390 would decide to start. We always had a Sears Diehard in that car, and the battery always failed within a year. We were always able to have it replaced under warranty, so Sears really took a financial beating when it came to this car. I learned all my curse words as I watched Mom and Dad try to start this beast. Funny thing was that it didn't even require cold weather to act up; it was hard to start in the Summer, too. We never figured out what the issue was, but I now believe it had a bad ignition switch (everything else was replaced multiple times).
2) the LENGTH OF TIME a battery has been sitting around severely discharged also figures into the situation; the longer the time, the less likely the battery will hold a charge. Having a motor home for a few years taught me things about batteries that I would not have learned otherwise. BTW there are quite a few people on YT that claim to have the remedy for such batteries, but I don't feel like blowing up my garage or risking injury to squeeze more life out of an obviously spent or internally shorted battery. Also, I have found that a deeply discharged battery exposed to prolonged freezing temperatures ruins any likelihood of that battery holding a charge. I learned this the hard way involving nearly new deep cycle batteries which were not topped off with a maintenance charge before a cold snap.
3) Just because a given battery is able to accept a full charge doesn't mean that this battery will successfully maintain the full charge. When my 2-year old OEM battery was failing, I put the car into Diagnostic Mode after trickle charging and put a load on the battery with the headlights. It was painfully obvious the battery was bad because it took only 2 minutes to drop the voltage to < 10V and stayed below 11V when I turned the lights off. I hurriedly ordered another battery at that point and quit driving the car until I replaced it 2 days later with an Optima Yellow Top (Amazon) for about $30 less than a Toyota OEM replacement. I've since gotten much better at turning the interior light off, but not perfect.. The new battery has much more reserve capacity than the OEM and started the car without the red triangle lighting up after the light being on for >24 hours.
BTW, I was hesitant to order the battery from the internet, since all my previous batteries during the last 40 years have been in person from brick-and-mortar shops, like Daniell, Interstate, and similar battery shops. The Optima arrived in two days, completely encapsulated with foam inserts on top, bottom, and 4 sides and the box was as sturdy as boxes come. And 12.7V out of the box.

CAUTION! A friend of mine's son replaced his battery in his gen 2 with a reconditioned battery that was approx. the same size and had the pos and neg terminals configured the same, but WITHOUT THE SIDE VENT HOLE. He had an audio amp wired (probably half-a***d) to the battery somehow. About 2 months later, the interior hatchback area exploded and caught fire while he was on the interstate (he had a bunch of clothes in the back). He was able to pull over and was not injured, but he didn't have a fire extinguisher and the car was engulfed within a minute or two. Moral of the story is to make sure that the replacement battery is specifically made for the Prius and has the side vent hole for the vent hose to plug into. This kid had no insurance to cover the fire.

If a Prius (or any car) needs to be parked for a prolonged period of time, the use of a battery maintainer can prevent a host of problems. If the hybrid battery sufficiently discharges, then that is a different ball of wax. I checked a few sites here and we are talking several hundred dollars, for a high voltage equivalent.

 

real easy answer: Stop buying junk batteries Buy optima Yellow tops

 

Well, I have the Optima Yellow Top, it was more-or-less the cheapest deal going when I purchased, but I'm not sure it's the optimum design. I don't know much about batteries, but I've heard the yellow tops achieve extra cold cranking amps at the expense of other characteristics, and that CCA is really not that important with the Prius. If there's a next time, I'm probably going with Canadian Tire's:

MotoMaster Eliminator Ultra AGM
Product Number: #010-5122-6
Manufacturer's Product Number: ELU-S46B24R

Which is apparently a rebadged:

Exide FP-AGM51JIS

It's a convetionally shaped AGM, same dimensions as the OEM Yuasa, and with proper vent port.

 

no, you should not be insulted. as long as someone is trying to be helpful, how the word their response, and how you perceive it can be two different things.
how's it going btw, you never updated us, did you?

 

here's my recommendation: @Mendel Leisk

 

Oh, dang, I've been poked.

For long term maintenance of charge, I'd think lower amperage would be fine, albeit if you want to use it frequently for overnight top-up, then I do not know, think you'd be better with something in the 3~4 amp range.

Any charger you're considering, see if you can download the pdf manual, see what they say about leaving it hooked up indefinitely.

I'm chauvinistic towards CTEK, no problems with them, but I'm not knowledgeable, just sticking with what's worked for me. I'm using a CTEK 4.3 for just that kind of maintenance charging, due to the car often sitting as much as 3 days, then just a grocery run or whatever. I also have a CTEK 3300, it's simpler/easier to use in some ways, but I'm used to the 4.3 now.

 

if it were mine id disconnect the battery all together and pull the orange safety plug so theres no drain on either battery.. then use the trickle charger on the 12 volt

 

Yes. A healthy battery will take less than .5 amps to maintain a charge once it is initially charged up.

And it it TOTALLY unnecessary to disconnect either battery during this time.

 

Hi-
It was not directed at you it was directed at Sam Spade. He criticized me for telling you to just get a new battery as so many people have damaged there car trying to rejuvenate a dead battery. The little battery in the back does not respond to jump starts very well and so many people on this site have reversed the jump leads and blown there car up. Mostly because they try to jump it at the battery itself which is basically a dark deep hole at night. the jump leads get confusing in there I guess. There's jump points under the hood that are safe and convenient.
Sounds like you went on the perfect path and just replaced it. You chose well. Good luck with it and your car.

 

I did no such thing. You are purposely mis-characterizing what I said.

Anybody who cares can see post #10.

 

I agree that charging a dead 12v battery for 5 hours at 2 amps is not enough time.
This does not mean that a new battery is required, but that the charge was not long enough.

A few years ago my Civic wouldn't start after not being driven for a week, and was down to 6 volts,
due to an unusual obd2 drain. I charged it overnight with my 3 amp charger, and the battery was quite fine.
That Civic battery lasted for more than 7 years, in great condition, until someone else took possession of the car.

Based on my experience, a battery that has not been maintained needs to be charged for at least a few days.
I almost always have the cars on a charger when not being driven, and don't disconnect the batteries to do so.

 

Yes. I have a schumacher 2 amp battery charger and charging my new optima YT from 12.6 volts to make the charge complete light come (13.8) is like 24 hours.
It works but takes forever. Once the battery gets up around 13 volts its a trickle charger at that point.

A 4 amp charger is better.