Fitting mobility 12volt AGM battery.

How could it possibly be that new readers "arriving at this thread" are going to be misguided by a lack of references when this is the 501st comment of a discussion that's been going on here since 2013?

I've provided plenty of references over the years and ever since this thread first started BrittPrius and I have been well aware of the relentless nonsensical attacks to our simple modest notion of using a 12v mobility battery instead of standard overpriced Toyota Prius 12v automobile battery, which is inferior in quality in terms of amp-hours. Heck, I still have the exact same 12v mobility battery in my Prius that I bought when we started this discussion and it's still hanging in their without issue. No way the usual 12v you buy could do that.

And if you want to talk about the dangers of hydrogen sulfide inside a Prius and you want to focus on the 12v exclusively... Maybe you want to take a look at a picture of balloons I always put over NiMH vent holes when I recondition/rebuild. These balloons are clearly filling up with hydrogen sulfide gas.

Or maybe instead you want to show me your picture of a 12v AGM mobility battery producing the same stuff when no one on PriusChat has yet demonstrated that after all these years...

Please provide just one measurable example of an AGM mobility battery inside a Prius producing Hydrogen Sulfide! That would suffice to prove your point, yet you offer none. And certainly you can argue your point theoretically via links/references, but in practice you still can't produce a single example or measure of a ventless sealed 12v AGM mobility battery inside a Prius cabin producing hydrogen sulfide gas.

 

By what reaction is the H₂S produced that you say is in those balloons?

 

There's plenty of discussion on here and elsewhere about what failing/overheated NiMH modules off-gas. And yes it's much more than just Hydrogen Sulfide and yes the reaction that causes it can at times be different/more than just thermal run-away.

 

You sound as though you're very familiar with it. Surely you've got a basic explanation what's making that H₂S ... especially where the S is coming from.

 

To be honest, I've read too much contradictory information on the subject and if I could afford it I'd mail one of those balloons off to someone could help us learn more about the the personal health risks involved in rebuilding/reconditioning hybrid battery packs. And if anyone wants to help with that I'd be excited to learn more and do all I can to make it so.

 

{where is the facepalm emoji?}

I never claimed to be an expert, but was bringing in some standard engineering due diligence that appeared lacking here. And asked PC for some additional information from his side. He didn't provide it.

Someone standing on a firm technical foundation won't respond with primarily ad hominem and invective. While I was trying to decide how to compose a response to his latest ...

... the issue of how NiMH batteries might produce H₂S was brought up. His replies to that tell me everything I need to know ...

{facepalm}

 

To repeat, for the benefit of other readers: None of the safety and compliance engineers I have worked with, ever took this narrow of a view.

Note that that high Prius charging voltage should be relatively brief, and it should step down to lower levels as the battery tops up, eventually dropping to a proper float voltage on long drives.

This assumes an absence of charging system faults. PC is likely correct that no one here has reported any Prius with this failure mode. But I also must note that most current commercial jet aircraft models have never experienced many specific failure modes of the kinds that cause horrific headlines. That doesn't mean the operators can ignore those potential issues that have only ever happened on a few other models.

This Prius battery risk is likely low enough that a fair number of people here will find it acceptable. Others won't. I won't get in the way of folks who go this route with eyes wide open. But if you prefer to take a safer route with the rest of us, just get a battery model that has the proper vent outlet, and plug on that tube.

 

Just to sum up my research. Those are the best manufacturers I found. I would not use random 'no-name' brands without proper documentation and certifications.

Ritar RA12-55
Ritar EV12-55
Ritar DC12-55
Power Sonic PG-12V60
SSB SBL 55-12i
NERBO NBC 55-12i
SunBattery SB12-55

Another story is to find a reliable supplier that stored the battery properly and not for too long.

I would avoid Tayna company (tayna.co.uk) as they sent me a 27 months old PG-12V60 battery.

 

Thanks to everyone for the suggestions. I found that Battery Plus carries Duracell 12V 35ah batteries for 89 then get 10% off coupon so 80$. It's AGM and has C type posts so it's very easy to swap out with original connection. Get 1 M8 1.5 inch long screw from hardware store that's all I needed. Cut 3 inches of 2x4 for spacer under the hold down bracket. Good to go

Posted via the PriusChat mobile app.

 

Congrats... I put a similar 45amp/hour sealed AGM for about $120 in my Prius in January 2013 and haven't had any issue, even several times when I left headlights on for a while, its never let me down!

 

I am a bit of confused after reading over 500 posts. In one sentence, there is no alternative 12V mobility battery with a vent hole to replace the expensive auxiliary battery in the USA. Is this correct?

The reason for the vent hole is because the auxiliary battery is located right under the rear seat in my Prius C, and the installation of the venting tube is probably more important than in a Prius, where I may be able to clip the auxiliary battery compartment open.

 

VW put 12v batteries under the back seat for 70+ years with no vent and no reason to do otherwise, which I suspect is also the main reason you can't find a 12v replacement with a vent hole. Meanwhile my ventless sealed 12v mobility battery I put in my Prius in Jan2013 is still hanging in there without any issues unless I leave a door open or headlights on... I have a new one on the shelf, but it just doesn't want to die yet.

But don't listen to me, take it from the "experts" on here about the extreme dangers of thermal runaway and the lone case where they couldn't rule it out as a cause of death as proof of how deadly the risk is...

Seriously, the odds of being struck by lightning while being attacked by a shark are just too great to even go outside, especially during a pandemic... Stay home, stay safe!!

 

Interesting. Does VW put batteries inside the cabin of all their cars or just some models? Do they use flooded lead acid batteries or AGM batteries? I never owned a VW.

Would you mind repost what battery and how you mount it, or give your original post number? I remember read your post before, but forget where it was. With over 500 posts, it becomes hard to look through.

 

I did my best with google image search to refresh my memory, but every type of battery that's been used in VW bus and bug since they were first made in 1938 have been designed this way. And granted there likely are some exceptions and I'm no classic VW expert, but...

Here's the one I always buy: 12 Volt (12V) 55 Amp (55Ah) VRLA AGM Sealed Lead Acid Battery 55 AMPS HIGH CAP | eBay

And it's slightly taller so you need to re-bend the mounting plate that holds the 12v in place over the top... Also when it arrives take the mounting bolts it comes with to the hardware store and buy slightly longer bolts of same thread size and then use some big metal flat washers to sandwich the terminals between.

 

Is there a Wiki on "Battery Alternatives For Prius" written up or being planned? Like the HV battery rebuild/repair, (I made one), I think there should be a Wiki on what to do and not do on this.
Thx.

 

Yea, that was a great HV write up that you did!
This ridiculously long thread is as close as we got to alternatives for 12v for Prius... Also @jacktheripper recently did a 12v Lithium DIY post that's on here from a couple months back.

 

If not going with OEM, use which batteries? (I've seen the 35AH U1 and your 55AH mobility battery)

Issues to add into the mix and to be considered when doing this:

Whether or not it's necessary to vent the aux battery (I know PriusCamper's thoughts)

Ways to adapt non JSI/SAE battery posts to work with the toyota clamps

Ways to safely secure the battery (shims, retrofitted clamps etc)

Effect of SKS/non SKS on success with other batteries. Effect of different battery AH on fuel MPG

Importance of buying a non- cranking "traditional starting" battery

I'm increasingly thinking of buying a 35AH U1 battery, about $65 locally as another poster got 6 plus years with it. Three remaining questions for me are venting, if I can buy adapter posts to screw into the tabs on most of these proposed batteries and whether SKS makes the smaller battery a problem.

I haven't read the Lithium aux battery thread, but it concerns me that the prius aux charging system was designed for Pb battery chemistry, which likes to be constantly fully charged and always a little overcharged with discharge stopped around 12v for battery healthy whereas Lithium cells don't like that and have duty cycles that go from fully charged down to very low. I'm concerned the prius will both not take advantage of the Li chemistry's potential and will potentially damage the Li cells if applying the Pb charge it was designed to do.

thx

 

--12v Lithium has its own battery management system (BMS)

--Meanwhile my ventless sealed 55amp-hour 12v mobility battery I put in my Prius in Jan2013 and cost $105 is still hanging in there without any issues unless I leave a door open or headlights on.

I have a new 12v one on the shelf, but it just doesn't want to die yet, or rather covid has it so I've no reason to to travel in the vehicle on overnight trips, so no reason to replace 12v yet. #stubborn

 

Thank you!

 

Looking forward to the Wiki on "Battery Alternatives For Prius".