Fitting mobility 12volt AGM battery.

I do understand your concern deviating from the OEM battery. As a retired EE I do understand the complexities of charging batteries and having done extensive testing of the Prius charging system find it near perfect on the gen2 Prius and even better on the gen3 for charging AGM batteries within a reasonable level of precision and cost.

The reason I say near perfect on the gen2 is because on the gen2 there is no temperature compensation as there is on the on the gen3.

The Prius battery under normal use can hardly be described as cyclic unless left for long periods of non use. It is closer to float standby use.

On opening the drivers door when the car has stood there is a current draw of around 12 amps rising steadily to around 20 amps, this lasts on vehicles I have tested for between 7 and 10 seconds. When the car is turned on there is a current draw for around 2 second of around 8 amps (varying) the The car electrical system is then run completely by the dc to dc converter, and the battery charged at between 13.8 volt to 14.6 volts "measured" at a maximum of 4 amps well in line with the battery manufactures recommendations. The battery then takes no further use in the normal operation of the vehicle and can even be removed without problem.

The cyclic information I have given is from the manufacturer and realize they are going to publish the best case scenario along with all the other manufacturers.

My own experience of these batteries "although I agree limited in the number of batteries used" does confirm the durability of these batteries in continuous deep discharge situations that the OEM does not handle well.

Further if so called mobility batteries only last as long as the OEM they will still be a much better deal.

As for your words on guaranty specifications these batteries are listed as being suitable for this application and the only advise from Toyota on this is to use an AGM battery

I and everyone here welcome any factual information on the subject and further I am not trying to discredit yourself.

John (Britprius)

 

I think "my description" of these batteries as "mobility" is perhaps misleading. Although this is one of the main uses it is far from the only one, being used in a huge range of differing equipment from communications equipment, fire alarm, emergency lighting, medical equipment, UPS, and solar power, to name a few. Perhaps we should just call them AGM batteries.

John (Britprius)

 

The voltage "after a long" (not required with the Prius, it has no alternator) drive is usually at 13.1 to 13.2 volts. This is with a typical 20 ma load of the Prius security system.

John (Britprius)

 

Sorry I did not answer your question as I was one finger typing and was beaten to it by Prius Camper.

John (Britprius)

 

The OEM battery is not a gel battery, it is an AGM battery. These should have no or very little free acid (loose liquid acid), but some including myself have reported reasonable amounts of liquid sloshing around in them. Having not long removed one from my friends car when I get time I will have a look in that to see if there is any free acid.

John (Britprius)

 

Generally speaking AGM batteries are supposed to stand up to being deep cycled. Some are considered deep cycled at 50% discharge.

The Prius OEM battery is notorious for not being able to stand up to this treatment without loosing capacity.

The amount of lead in a battery basically sets it's capacity, the OEM battery is 15 lbs lighter than the similar size so called mobility battery. Must be a lot of empty space in the OEM

John (Britprius)

 

Ib

I believe that sums up and validates what I have been saying and fills in any information gaps I may have left out.

John (Britprius)

 

Did PC go down for a short while I have not been able to access for about 30 mins.

John (Britprius)