Fitting mobility 12volt AGM battery.

In post #133, Britprius described a way of adding a vent hole in the lid of an otherwise no-vent-hole battery. He also mentioned that even the "no-vent-hole" battery actually should have vent slots on top. I am not sure if PriusCamper wants to check and confirm on his batteries.

 

Thanks - PriusChat is the first forum where I've been introduced to (the admitedly useful idea of) referenced reply comment numbers!

 

Very helpful photo thanks. I was thinking we'd have to adapt the tabs (via the threaded female cutout) to SAE/JiS posts, but maybe the secret is just to connect via the screw, as you did. Is the max current draw adequately passed by those screws? There's a lot of surface area that's lost by not using the posts to connect to the car...

 

@PriusCamper Any special requirement for the longer bolts to avoid corrosion long term?

 

Nope... I've never seen corrosion on a 12v battery in a Prius... I'm not saying it's not possible, I'm saying It's not something I've ever seen.

 

It's also possible to make links to them: the small grey comment number down in the corner of any comment can be used to obtain a direct permalink to that comment in context. That can save others time finding that comment in a thread of many pages (or a thread that isn't that long when the link is made, but later grows to many pages).

 

Awesome: Fitting mobility 12volt AGM battery. | Page 27 | PriusChat

and

Fitting mobility 12volt AGM battery.

 

I didn't know that.

Thanks!

 

I know that there is has been much discussion/debate about whether these batteries really need to have a vent tube. Still, if I could find the right battery, with a vent tube, I would probably prefer it. Well, today, I think I have found a way to get one of these batteries installed, and to so do as close to stock as possible, and doable for people in the USA. Requirements:

NPP appears to make a 12-55ah batteries with M6 insert terminals, almost identical to Britprius' battery, shown on page 1 of this thread. You can buy this battery from amazon.com for $119.99 (free shipping). On the amazon page, you can clearly see a vent tube on the side. Also, the size is practically identical to Britprius' battery: 9.06x5.43x8.31 inches (LxWxH).
http://www.amazon.com/gp/product/B01LWA9NFJ

I assume that the battery vent tube will be similar to that of Britprius' -- in that we might need to use a small section of windshield wash hose to go from the battery vent tube into the stock vent tubing in the Prius. I have not investigated/confirmed what size of hose would fit.

Then, for a stock mounting setup, add a pair of Odyssey M6 JIS style terminal adapters:
Odyssey batteries - Terminals. These are $14.95 ($5 s/h). This should allow the battery cables to mount to the battery, just like the original battery. Please correct me if I'm wrong.

In total, this would be $139.94+tax, assuming you can get the little section of hose for free.

 

No reason to spend $15 on terminals when you can spend less than 4 dollars on some longer bolts that match battery thread type and some big flat washers to sandwich the terminal in between:

 

That is definitely true, unless you want something that looks almost like it was stock.

 

Well there's nothing that looks OEM/stock when it comes to using a better AGM 12v in a Prius...

 

We bought a 2011 Prius last month. It came with a regular lead acid battery (wet) - Group size 51, with the posts shaved down to fit the JIS connector. So, was looking for a cheap way to upgrade to a non-spill-able AGM battery.

Initially, I planned to go with the Duracell Platinum AGM Battery (Group Size 75/86) from Sam's Club for $111
https://www.samsclub.com/p/duracell-agm-automative-battery-group-75-86/prod21234616
It was readily available at my local store, and if anything went wrong, I could just return it. But then I realized, I needed to buy the SAE cables and adapters, and also modify the mounting plate to fit the larger battery size. Plus its vent hole is an odd oval shape and fitting the OEM vent tube to it would need some creative thinking. All of it seemed like too much work.

I almost decided to pony up the cash for an OEM battery when I came across this thread. A 55Ah battery for about half the cost of OEM? Seemed interesting, so I looked into it a bit and found the following options for 12V 55Ah AGM batteries with a vent hole and M6 Insert Terminals.

ExpertPower EXP55A ($105 - $125)

12V 55Ah Rechargeable SLA AGM Battery for Wind, Solar, and Off Grid Power | eBay

PowerStar AGM12-55 ($120 - $135)

PowerStar 12V 55ah SLA AGM Battery replaces Duracell SLAA12-55C/FR - Walmart.com

NPP NP12-55Ah ($140)

Interstate Batteries DCM0055 ($140 - $160)

If you don't care about the vent hole, then the cheapest one I found was the Protek SL12-55 for $90 on eBay

I ordered the ExpertPower EXP55A for $110 from their eBay store. It was delivered today via USPS. Packed well, double boxed. Out of the box the battery showed 12.9V. I hooked it up to the charger to top it off. Plan to install it this weekend. Will update with some pics after I am done.

 

$90 is too cheap so is likely inferior in quality. I wouldn't expect it to last very long.

 

Thanks - this is a very helpful post. I may never get around to venting the battery I put in my 04 Gen 2, because I've been told by my local independent and by the dealer it needs a very expensive gas tank due to 'very small leak' P0456 and the exhaust manifold is now leaking. However, this first Prius has hooked me; I'll look for another gen 2...

 

Just factor in it'll probably need a new HV battery, then they *should* be cheap. Strangely enough, they don't seem to go down much in price here (Netherlands), very few under 4000$ despite 200k miles and 15 years old... Bought mine for 12000$ when just 2.5 years old...

 

Many devices used indoors have non-vented AGM batteries in them. The uninterruptible power supplies used widely in office buildings to keep equipment running in case of power outages use them. Also, they are installed in security systems and emergency building lighting.

 

Bought the ExpertPower 12v 33ah Rechargeable Deep Cycle Battery from Amazon for $75. Its a sealed AGM. No vent. Not sure how long it will last but has good reviews on Amazon. Its a little short to fit in the OEM battery bay so I put a block of wood underneath to make it fit. I have a non smart key 2007 Prius so 33ah should work just fine. I also didn't have to buy any extra screws of hardware to hook up the battery. I used the screw that came with it and washers that were on the OEM cable screw. It screwed on nice and tight. It's working like it should. Will update over the next weeks and months.

 

I’ve been using at $60 35AH AGM in my sks 04 for a year. It’s been great. Yes, it has 20%ish less capacity than the oem 45 AH battery, which costs 200+.

 

I put in the 35ah as well. I'm not worried about it failing all of a sudden. I got a Konwei digital battery tester for all my battery capacity testing needs for $18, it takes the guesswork out of battery replacement intervals.