Fitting mobility 12volt AGM battery.

My first post on priuschat. Last winter, in Jan 2016, I had to replace the battery in a 2008 Prius and thanks to this thread that I could do a quick research and find a Ritar RA12-33 compatible battery in my area Toronto, Ontario, Canada.
After almost one year I can report back that the battery works fine. I can't post the link but those interested can find the small battery shop by searching upsbatterycenter

 

well done, thanks for the update!

 

I sincerely hope you never need the safety features that the correct replacement battery has.

 

I remember one year ago how surprised was the owner (Anton K.) of the battery shop when I showed up at his door and I told him that I'm looking for a Prius battery )))) Lucky me I had a print out of this thread so he didn't think that I'm crazy.
He kept telling me that he thought that he knows everything about batteries but never thought that one of his batteries could fit a Prius

 

Great information. Thanks John!

 

9 weeks of not using the Prius (standard small battery replaced by 55Ah AGM in 2016). Started right up!

Only used it to drive 10m across the public parkinglot to be close to my garden (=powersocket) and the 3.8A (3, 4, 5? stage) charger took somewhere between 12 and 20 hours to fill it up again (finished somewhere during the night). 12.2V when I started iirc, but this was AFTER the 10m drive, so after the 200=>14V inverter had charged it for half a minute.

 

If you're looking for an "off the shelf" quick and cheap solution, the solar batteries from Harbor Freight will work. It's only 35A, but will do. Normally $70, you can get them on sale occasionally for $50. Standard hardware will work, just have to attach in a little different way.

 

That's in interesting discovery. The 12V 35AH battery sold at HF is sold with and for solar application. It is interesting to note that the user manual states, "Avoid over-discharge and deep discharge." Reading the user reviews, it seems that like many (but not all) items are HF, it is of low quality and the 35A maybe over rated.
I just discovered this thread and was looking for Ritar brand batteries here in the US but it seems that they aren't available. All I can find are "Ritar replacement" or "Ritar compatible". I'd like to avoid crappy compatible ones. Can anyone recommend some (with model numbers) that are readily available in the US (and fit properly).

 

None of these batteries will fit off the shelf, The Prius uses JIS posts which are rare in the US. Your passengers deserve externally vented, AGM batteries. (If you never have passengers, then the scarring is not our concern) The correct buzzword for the right battery is S46B24R. Many vendors exist, most auto parts chains have one.

 

There are a bunch of similar AGMs for sale in the states, but not the Ritar brand

All of the others that I've found so far are a .1 (tenth) of a inch shorter, and 3 lbs (of lead?) lighter.

Ritar does appear to be doing business with OEMs in the states, but not with their own branding.

They must be private labeling for someone ?

 

I created an account just to thank John and to share my experience with replacing the 12V battery on my 2011 Prius. I bought the car used about a month ago, and it was sometimes failing to go to "ready." I was able to eventually get it to start by holding the power button for 5-10 seconds. Internet research revealed that it was probably the 12V battery, which I tested with an analog multimeter. It was somewhere between 9 and 10 V. Having found this thread, I ordered a 35Ah Keyko battery from Amazon for $79 shipped (KT-12350 HRT). They also make a 55Ah battery, but it is ~1 inch taller than the battery in the car, so I didn't want to risk not being able to install it. This one was shorter than the original, but I put a piece of 2x4 (which is 1.5 inches thick) under it and the height was then perfect. The part that I was the least confident about was connecting the L2 terminals, but they fit once I spread the jaws of the connectors out a bit, and when I clamped it all down they felt solid. On the positive terminal, my car has a plastic shield, which I had to open up (there is a hinged bit that can be pried up with a small screwdriver). But it did all go back together, once I had tightened the connector over the terminal. the connector bit into the terminal at the corner, and so the terminal molded into the right shape.

I did look for vents to try to rig something up, but don't see them. But I've tried to collect hydrogen gas created during hydrolysis for a teaching demonstration, and even collecting it under water, it can be hard to ignite it. So I'm not worried about it.

So thanks for the thread. It's starting the car quickly and I'm glad for the learning experience. I have a few pictures of the terminals in case they might help someone else

ETA: You will need 10mm and 12mm sockets on a socket wrench. All the bolts are 10mm except the one on top of the positive side, which is 12mm.

 

I've had one of these unsafe KILLERS in my Prius for over three years and not a fatality yet. I've posted it somewhere on PC before, don't remember which thread. I installed it the same as yours and used a 1 and 1/2 in. block of wood on top and it's as secure as the original, just lighter and lots cheaper.
UPG 12V 35AH Group U1 Deep Cycle Sealed Battery | eBay

 

Nice to see such a high voltage with the head lights on.

Posted via the PriusChat mobile app.

 

I thought about using one of these batteries when I found out the Prius battery was AGM. One thing that concerns me is making sure there is enough surface area contact with the cables to the terminals, a few of the pictures I've seen look a little sketchy. With the OEM round posts and the round clamping cables there is a solid connection. Has anyone found a good way to connect the cables providing a contact area equivalent to the OEM setup?

 

I wouldn't be at all concerned with the contact area. Think of the small contact area you have when using jumper cables to start a conventional car/truck. That relatively small contact area is carrying huge current loads -- well over 100 amps constant, and double that for the initial surge.
However, you can never have too much current capacity. So these might do the trick. I don't know how they would affect vertical fitment.

 

nice to hear your voice again john, i hope you have a wonderful 2018!