optima yellow tip overrated?

Thank you Patrick.
Your comments got me interested enough to check the battery in my early gen 3, built in 5-09 and bought by me in 7-09. (Just over 50,000 miles)
If my little Harbor Freight / Cen Tec DVOM can be believed, cold battery voltage (last run 15 hrs ago) is 12.70V at the fuse box jumper connection, so that 5 year old battery may still be fairly healthy. Maybe because I live in a very rural area of the country, and my nearest shopping town is 42 miles distant, with larger towns being 90-150 miles distant, the Prius gets long hours on the road to recharge the battery, almost no short trips.. Also when I park the car for 2-3 winter months, it is constantly on a good quality AGM safe charger/ maintainer/ desulfator (BatteryMINDer, hard wired to the battery).

Cold charge voltage(Ready mode with ICE running) was 14.50V at the jump start connection, but others have posted that when the system warms up and stabilizes, that will drop into the mid to high 13's.

 

I'm not sure I see the connection between the amount of driving and battery longevity. I haven't heard that monthly charging is beneficial, unless you mean desulfination maintenance, which is not really related to typical automotive applications. I think battery longevity is determined more by the amount of charging and discharging, vibration and heat. Not to mention the design.

 

That's just the way a voltage regulator works.
When the battery approaches a full charge, the charging voltage goes down.
Anything above 13.2 or so is a perfectly acceptable float voltage.......IF the battery really is fully charged, or very near to it.

If the charging voltage falls off to a float value BEFORE the battery is fully charged, then you can have a problem.

 

Yes you have. You have just elected to ignore it or have forgotten.

Several people here have said at various times that keeping it fully charged is best........and that if you don't drive it regularly a periodic charge will accomplish keeping it charged and extend the battery life.

 

I really don't know what you're on about. Are you talking about an idle battery? I was talking about a battery in a regularly driven car.

Anyway, we're getting tired of the way you're making nearly every one of your posts a personal complaint. It's not about us, it's not about you, it's about sharing information.

 

One of the problems with the Optima battery not touched on so far is it's lack of capacity for use in the SKS versions of the Prius. Toyota in the SKS Prius fitted a 45 AH battery. In the non SKS versions they fitted a 35 AH battery. They did this for a reason.

The Optima is only a 38 AH battery and as such reaches a deep discharge level sooner than a 45 AH battery. A deep discharge is usually considered to be 50% discharged although the battery will still function well below this level the deeper it is cycled the shorter it's life.
The reason for the Optima's lower capacity is down to it's construction "round cells" making poor use of physical space"
Removing 20 AH of charge from the Optima represents a 55% discharge. Removing 20 AH from a 45 AH battery represents a discharge level of 44% a much shallower discharge. This applies to whatever level the battery is discharged to.

As some of you will know I use a "mobility" AGM battery in my own Prius. This is rated at 60 AH so removing 20 AH on this battery gives a discharge level of only 33%.
My battery still measures 12.9 volts after sitting over night. This is partly due to the fact that we did not get SKS on the gen2 Prius in the UK and the charge being removed over night is a smaller % of it's capacity. This battery is getting close to three years old, and was over £100 cheaper than an Optima.

In the UK Optima batteries have lost sales for car use because of there very high prices here, and the availability of more cost effective solutions. I will not go into the now obvious problems they have been having with batteries being delivered or supplied in a discharged state for whatever reason.

I was concerned about the charging voltage from the Prius, but in normal use I see initial charging voltages as high as 14.4v settling eventually to 13.8v. I would like this to be a little higher say +0.4v, but raising the initial voltage to 14.8 volts would give some very high charge currents.

John (Britprius)

 

And I'm getting pretty tired of YOU claiming that you did not say things that you DID say.........and attacking me for pointing it out.

The connection between infrequent vehicle use and pre-mature battery death has been discussed to DEATH on here and YOU have participated in those discussions more than once.

It is possible that you still don't understand it but you can't say that you have "never heard it".

 

Thank you John.
When I read your earlier posts where you adapted the Mobility battery, I thought your idea was a win win deal.
You thought that the Mobility battery is constructed with the idea that it will see deep discharge cycles in normal daily use and may well take deep cycling better than the Optima or other batteries, plus it is lower cost and higher capacity. I think that is what I will try when my original gen 3 battery gives up.
The Optima battery is very expensive for that size battery in the US also. I suspect that might cause slower sales and more old sulfated battery stock on store shelves, possibly leading to already sulfation damaged batteries before they are sold / installed. That problem should fall on the dealer, as it is his responsibility to maintain the battery in fully charged condition until the time of sale, but I suspect that job is often sadly neglected.

 

I do not wish to stray to far off topic, but I have taken the use of these batteries one step further, and I am now using two of the same batteries in my caravan connected in parallel to give a capacity of 120 AH. I could have bought one battery with that capacity, but two smaller ones give easy er handling and greater versatility.
They operate all of the 12 volt systems in the van when a mains hookup is not available. They also supply the motor movement system enabling the van to be parked by remote control in tight spaces.
Reich Move Control english Image Video - YouTube
John (Britprius)

 

Perhaps you could get tired enough to leave us in peace.

 

Not very good form to deal with such things publicly.

 

I don't deny climate change. However, the belief that man made co2 is destroying our planet is bunk, and like a fanatical religion. How many times are they going to repredict the melting of ice caps flooding the whole earth? They are proven wrong every day because it still hasnt happened. Ok, off my soapbox

 

sorry?

 

It is not bunk. "Things" are happening every day that can't be explained any other way.
You are listening to the wrong people.......talking heads instead of trained and experienced scientists in the field.
This is another case of "Don't confuse me with facts because my mind is already made up."

 

My slightly informed opinion: Optima used to be an excellent battery, but the original company was bought out by a mega corp that is now milking the brand name recognition but not keeping up the quality.

For my recent 12v replacement I switched back to OEM Toyota. The capacity is now higher and the warranty generous. The cost works out to about $2.5 a month.

 

Both important points.
I assume it is a completely sealed AGM type ?
How does the cost compare to other major brands.......or did you even compare ??

 

While not politically correct, I am a strong supporter of benign dictatorship.

Good for Tony.

 

Yes, sealed AGM with a vent.

I found one alternative in our local stores but it was more expensive than OEM on a cost/warranty_length basis.
Not specific to the battery required for the Prius, generic walmart batteries cost about $80 for 48 months of warranty IIRC. That works out to $1.66 a month, so the Toyota OEM is under $1 a month more expensive. At this point I invest my time elsewhere