Gen 4 12 Volt battery.

One example does NOT establish a pattern.

You are an exception.
Exceptions just serve to prove the rule.

Or......to put it another way, when you are averaging a LARGE sample of anything, there almost always are a few exceptions at both ends of the measurements. For every conventional battery that lasts 13 years, there is at least one that dies in two years or less.

 

How often do you check the "water" level ??

 

never, i think it says maintenance free, but i'm in florida, so can't check until late march.

 

The average consumer needs to know only 3 things:
100% maintenance free.....under normal use.
Lasts up to twice as long.
Usually costs from 50 to 80% more.

Not too hard to "understand" those things.

 

As I've had experience with several battery types over the years both home use and in various job positions, here are the main differences between a conventional "flooded" lead acid and AGM (Absorbent Glass Matt).
AGM's, if the case is damaged typically won't leak electrolyte, as the Matts between the plates are usually about 10% below saturation with the sulphuric acid electrolyte. Standard Lead acids will, along with the resultant corrosion damage from the leakage. AGM's also tend to allow the Hydrogen and Oxygen to recombine into water when charging so they conserve the electrolyte. AGM's are vented with safety valves, but during normal operation the valves do not open.
The primary thing to remember about BOTH types of lead-acid batteries, is that discharging them below 50% capacity will quickly reduce their cycle life ending in a replacement being required. 20-30% is the recommended discharge depth for max battery life. Staying within these limits should result in your 12v battery lasting quite a long time.

 

That is only partly true.
Deep discharge of a "wet cell" results in increased sulphation.
AGMs are not prone to sulphate......at all in normal use and not much when abused.
That seems to be the main reason for their longer life.

 

Deep discharge? Isn't that one of those extremely cases you mentioned?

 

Who ?
And what exactly are you saying/asking ??

Yes, running any battery completely flat is generally not good.
How bad it is depends on the chemistry involved.
AGMs usually withstand that better than wet cells.
Lithium maybe even better; don't know about them.

 

Although the Prius with a Lithium pack is carefully managed by the cars charging system, Lithium cells, if allowed to discharge completely will destroy the batteries electrodes.

 

The 12 volt battery is not Lithium in any Prius.

 

I was referring to you post #43

 

Referencing a Lithium traction pack Nickel Metal Hydride, sorry to confuse with the aux 12v battery. If however however anyone has questions in-depth about battery types, look up "Battery University", covers all the various types.
.

 

Post 43 in this thread was made by Bisco.
Using the quote feature would help a LOT.

 

Typo, sorry #42

Do keep up with what you've already said.

 

Here is post #42.

Stop wasting our time with nonsense, please.

 

Sorry

 

In a colder climate I’ve had to changed the 12v battery after about 5 years on my gen 2 and gen3.
But I bet it’s much longer if you live somewhere warm.

I replaced mine after first signs of trouble and it was -20 celsius outside on both occasions.

 

My battery indicated not holding the charge. I had the emergency lights flash for 5 mins and I won't able to get the ready light came on, it happened couple times while I was in the parking lot charge my phone for 5 mins. Another indication is my MPG going down big time. So today I changed the battey, everything back to normal. MPG going back up I am real happy for the result.