Replace OEM 12V battery with Group 25 AGM

Is this a better solution than the Optima Yellow top DS46B24R

 

Double Post

 

By "this" are you referring to the type of battery described in the initial post of this thread, ie: a bigger, larger capacity battery?

If so, do not know. It takes some work, leaves the car sort-of non-stock, I wouldn't bother.

 

You can compare the provided specs.

Optima Yellow Price: AMAZON PRICE: $159.84 & FREE Shipping
Model: DS46B24R
CCA: 450 Amp
C20 Capacity: 38 Ah
Weight: 26 lb
vs.
Group 25 Battery RK-AGM25 PRICE: $129.00 (In store pick-up) Looks like they stopped the on-line sales.
Part Number RK-AGM25
CCA at 0°F 650 Amp
RC MIN @ 25A 110
Ah Cap. @ 20hr 53
Weight 41 lb

I find the bigger AGM battery to be a better choice.
Modification and extra parts are required, see posts, not a direct drop in.

I still have all the parts if I need to return it stock.

 

Yes. The battery in the OP.

 

Yes. The battery in the OP.

 

Yes. The battery in the OP.

 

Looks like the Tapatalk app likes to post double and tripple times!

 

So, on the one hand, save $50, and get a bigger battery with more engine-off runtime, and possibly less worries about cold-weather starts. Modification allows you to use SAE-terminal AGM batteries rather than having to stick with JIS-terminals. (In an emergency, battery can now be replaced by a standard US-domestic lead-acid battery.) Removing battery and tray also gave me the opportunity to clean the area and mouseproof that part of the car.

On the other hand, you need to modify the car from stock a bit (reversibly, but still), and the larger battery is heavier than stock.

I've seen conflicting opinions about the Optima batteries, and that was enough for me to decide against them.

A plus, for me, was getting my feet wet about modding the car - it's by far the most expensive car I've ever changed from stock, and I was pretty nervous about it.

 

I can double and triple post with the best of 'em, using Safari on iPhone, or on a desktop Win10 pc and Firefox or Internet Explorer. It's the site that's acting up, AFAIK.

I'm about 16 months in with an Optima, not bad so far, but it's voltage will drop if the car's sat a few days, just like the OEM. I might try Canadian Tire's Motomaster next time. It's a rebadged Exide, AGM, same dimensions, posts, and vent port as OEM. More CCA and cheaper too.

 

With the larger battery the car is constantly in EV with my foot off the gas. I see the rpms slowly go down to 995rpm than it drops to 0.

Coming up to a stop light with the heating on and fan at 50% the ICE is off. The entire stop light the ICE is still off.

I am working on some ideas to see if I can measure old battery vs new larger battery but it's too cold here to play outside with the batteries right now.

I'll keep posting to let folks know how long the EV experience lasts.
thx.

Mentioned above: I also like the idea if I am in a jam I can now plug any 12v, normal size terminal + - post in the car. No more tiny battery terminal post, going forward.
The battery if more heavy so I will need to go on a diet. HA

 

Remember folks, even with SAE posts instead of JIS posts, for the safety of your passengers, you need an externally vented battery. (except gen 4 where the battery is already external)

 

Yes, follow the instructions and the venting is identified and well defined.
The kit I bought had everything I needed and fit perfectly on the larger battery that only came with an elbow.
It even came with a floor plug that I did not need to use since the Toyota floor plug fit the hose kit.

 

I'm also going to mention that the group 25 battery is about the upper limit for reasonably priced AGM batteries. I looked into it (because sometimes bigger really is better). Getting a larger, more powerful size (which moves you more into the realm of truck batteries and would probably require a custom bracket) starts costing quite a bit more money. There's room in that area for a larger battery, though, if someone felt compelled to try it.

Looking at the equipment choices the Toyota engineers made for the Gen 3 Prius, it's obvious to me that trade-offs were made to reduce the weight of the car in order to improve the gas mileage. I think the small size/lower weight of the OEM battery was one of those deliberate trade-offs.

 

Hello Mendel,
Do you have a part # on the Canadian Tire Motomaster that would work in a 2ndG Prius? Being in Michigan I travel frequently to Toronto and may pick one up.
Thanks
Simba

 

I tried plugging in 2009 Toyota Prius, get this:

Automotive | Canadian Tire

Just in case the link acts up:



For my 2010 I get the same result. Here's the stat's in text format:

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

 

The link worked perfectly. Thank you.
Simba

 

You'd want to change your Canadian Tire location to the one you'd be going to, but I'd suspect everything would be the same, ie: part numbers, prices. You can also check stock of the local store. There's invariably none at my nearby store, but typically there's a couple of Greater Van stores that do stock it.

The time I did by a battery from them (for another car), they had a nice digital load tester, and were happy to hook it up, check the battery. All worked out fine.

 

Need advice. It seems that my original 12v battery on my 2011 GEN III Prius is dying. It all started with the arrows disappearing on the Energy Monitor. After digging in deeper into the subject I learned that the cause might be the 12v battery. I went into the Maintenance Mode and the reading for my battery was 11.3v. There are no other symptoms. I know that a good replacement would be Optima Yellow Top but it's quite expensive here and not widely available. My alternative is Yuasa YBX5057 or YBX3057, like the one here:
YBX5057 - YBX5000 Silver High Performance SMF Batteries - Automotive - Batteries
or
YBX3057 - YBX3000 SMF Batteries - Automotive - Batteries

Would anyobe be able to give me a recommendation? Does a charge of 11.3v really mean that the battery is on its last legs?