12v battery Replacement

Thanks.

Let me say that where pickiness is concerned, I've got you handily beat
A difference in nomenclature implies the use of different symbols for the same meaning,
while amp/hr and amp*hr are different meanings.

Cheers

 

Hmmmm, I don't know if I agree 100%, in that nomenclature doesn't imply anything of the sort. As amp/hr and amp*hr are not names per se but expressions (or formulae, if you like), I'll give that one to you.

 

The nom in nomenclature sounds is the french word for 'name' in English, so nomenclature means "
the devising or choosing of names for things, especially in a science or other discipline.

• the body or system of names in a particular field.

"
According to Google definition, which sounds right to me.

One society might write A*B to mean "1 multiplied by 2," and another society might write
1 x 2 to mean the same things. Different nomenclatures, same meaning.

Neither would ever mean 'one divided by two'.

Sorry, I like words, very much enjoy etymology, have an unfortunate habit of nitpicking, and very much appreciate rigor in thought and expression.

 

This I agree with 100%.

Me too.

 

just bought the yellow top to replace my 2007 oem battery only gave $150 for it delivered new which was cheaper than I could find the oem one.... Had great results with optima in the past, hope they are still up to snuff...

 

12v battery replacement is so easy and inexpensive, it shouldn't even be a concern for owners. If the battery goes bad after 3 years, just replace it. $150 is about the cost for a tankful of gas if you drove a F150 truck.

 

"Mail order" batteries come with an unknown state of charge.
They always should be charged, preferably with an automatic charger, before being put into service.

 

This only applies to resistive loads, inductive loads can have the reverse effect.

John (Britprius)

 

Isn't this discussion about DC batteries ??......where induction is not a factor ??

 

Go back to school. An inductive load is a factor with a DC supply.

John (Britprius)

 

This is an explanation I am itching to hear.

Past the initial surge of current when the supply goes on or off, inductive and capacitive properties of a circuit do NOT affect the current flow in a pure DC circuit......as long as there are no re-occurring surges, which would make it an AC voltage or pulsed DC instead.

I may need a refresher on some subjects or details........but not this one.

 

I think the clue is in my wording. "inductive loads can have the reverse effect" notice I used the word "can" and not the word do.

John (Britprius)

 

I'm tempted to mount a tube containing 9 alkaline D-cells somewhere in the car, with a switch to boost my aux battery if it ever goes dead again. The reason I'd use alkaline cells, is that they don't lose their charge over several years. Simple solution to a simple problem.

 

A small 12 volt sealed agm battery of the type used for burglar alarm backup works well. Permanently connected to the OEM 12volt battery through a diode with a switch across the diode will be kept charged. At the flick of the switch will boost the 12 volt system.
I use an old laptop power supply off the HV battery as an emergency backup. This will actually charge the 12 volt battery.

John (Britprius)

 

Just bear in mind that there is a lot more to a battery than just its advertised Ah capacity rating. Optima YT has clearly had some QC issues in recent years, but historically is a great battery. Excide Orbitals are another with a similar reputation, and I'm sure there are others out there as well. The difference in internal resistance and Peukert exponent can easily give these batteries more effective capacity under load than batteries spec'd for more Ah at the standard 20 hr rate. Probably more importantly for this application, they also tend to lose a lot less capacity each time they are run to low SOC (as both are designed as a true deep cycle). There seems to be a lot of evidence by now that just running the stock battery low a few times (leaving cabin lights on overnight, listening to radio too long, etc) takes years off its life. A true deep cycle AGM like the Optima YT or Excide Orbital should be able to do that 10s or 100s of times without substantially degrading their lifespan or capacity which should help them last considerably longer in a Prius.

FWIW I'm 5 yrs into my Optima Yellow top on my Gen 2, with no signs of trouble. This is almost unheard of in Phoenix, where our ridiculously high summer temps (110-120F ambient, easily 140-170F in a parked car) really do a number on car batteries. Typical on any car here seems to be more like 2-3 yrs average. Anecdotal to be sure, but I've been very happy (bought kit from elearnaid).

Am I correct in remembering that part of the issue with the YTs were people getting supposedly "new" units with old date codes that had been sitting around quite a while and/or were not stored fully charged?

Rob

 

I ran a post about fitting an AGM mobility battery in the Prius some time ago. The battery I chose fitted in the OEM space with the OEM tray and hold down clamp. The battery is rated at 55 AH capacity, but this is at a 10 HR rate making it well over 60 AH capacity when rated at the same rate that the OEM and Optima batteries 20 HR rate.
These batteries are designed to be deeply discharged on a daily basis with no ill effects. They can also be recharged at a higher rate. My battery now fitted over 3 years ago still reads 13 volts after standing overnight fitted to the Prius. Further they cost less than the Optima.
I now run 2 more as the 12 volt supply in my caravan also powering the motor mover system. (moves the 2240 lbs van around on it's own radio controlled electric drive system)
The down side? The battery is heavier (more lead content), and the terminals are threaded holes.
The problem with cylindrical batteries is there poor use of physical space. Meaning there capacity for a given footprint and height is lower than the same size flat plate battery.

John (Britprius)

 

Considering how little load a Prius aux battery experiences in normal use, it should last a good long time. The damage comes from letting it go dead occasionally. That's why I think they should have given it a deep-cycle battery to begin with.

 

John, I would think something like that could be a great choice for a Prius. Even a smaller, lighter (and cheaper) version with less Ah would probably work great for a long time. The only trick with this type of battery may be that there are lots and lots of different brands/versions that all try to paint themselves as equivalent based on their Ah rating and form factor that vary widely in quality and other specs. I would think that ones marketed specifically for mobility applications are likely to be better in terms of cycle life than those intended primarily for UPSes and power backup, though even those might do fine in the Prius given that they are only occasionally (usually) cycled deeply. Those not intended for mobile applications may also not take kindly to the vibration environment in mobile applications. Temperature specs might be another thing to look at on these, as consumer components are sometimes rated for a much narrower operating range than automotive components. The only other downside I can think of is these types of batteries are not likely to have a hookup for an external vent in the (presumably quite rare) case of an over-charge failure.

My understanding comes mostly from the EV conversion world, where the orbitals and optimas really shine (compared to other PbA at least) under high load. Given the fairly low current demands on the 12V in the Prius, that's probably not so relevant. You're probably right about the space efficiency of the spiral cells in this application.

Rob

 

I don't use the "acc-mode" anymore. I just leave it in the "on" position instead, when I need it, so that the aux battery never runs down. The engine kicks-in sometimes, as needed, it's much easier than worrying about running the battery flat.

 

There is a smaller cheaper version of the battery rated at 33 AH. The post is linked below most of the information is given in post (9) The battery I am using is vented.
Fitting mobility 12volt AGM battery.

John (Britprius)