Fitting mobility 12volt AGM battery.

I have something similar (Autool BT360), but it gives some strange results sometimes...

Some battery came with 3kW 230V~ inverter that I wanted to buy second hand and easily ran a 500W powertool without dropping in voltage.
When checking this >600$ battery at the sellers place, the Autool showed something like: SOH 100%, SOC 15%, so bought the whole setup thinking the battery alone was almost worth the purchase price.

Came home and rushed to charge the >100lb 200Ah (!) AGM Deep Cycle with my 3.8A charger, but the charger 'refused' to go beyond the 0.8A motorcycle chargingcurrent, so left it for two weeks. (Later checked charger on other batteries and works fine).
Now SOH is 15% and SOC is 90% or so and I am adviced to replace this battery by the Autool... No way the charger can have wrecked it with such low current imho, so I am questioning the Autools reliability...


BTW, the battery does not fit the battery-cavity on the Prius...

 

The listings for AGM batteries usually include the dimensions, so just make sure it will fit before ordering it.

 

If you were refering to me: it was a joke. This 200Ah battery is humongous and weights ~130 pounds and was bought with a 3000W 230V~ inverter for my grid-less garage. Was never intended to go into the Prius although when the zombies come, I can hook the battery + inverter up to the Prius...

 

Can
You show us how you connected your new battery? I had to convert the car’s jAL clamps to SAE posts.

 

So I'm thinking about ordering the ExpertPower 55Ah PriusCamper and bzbee have recommended here, but I noticed the dimensions on ebay don't actually match what I'm expecting, they're: 9.00" x 5.40" x 8.43" (LxWxH) which is actually a bit wider than the Yellowtop/Autocraft/Diehard batteries I've had (9.94 x 5.06 x 8.94 inches), but is less long and less tall(?).

So I'm not sure what to expect for the install. Fortunately these dimensions are almost the same width (5.39") as the Duracell DURDC12-55P that sugarlanddave installed in post #425, and apparently that fit fine:"At slightly over 42 pounds, it is the biggest battery that I could fit while still keeping the tray and hold down bracket."

I plan to use the M6x1x25mm bolt+washers sandwiching the terminals that PriusCamper describes in #503 so I don't need any terminal adapters. Fingers crossed everything just works!

Side note to any other thread newcomers: use the "Search this thread only" toggle in the top-right search dropdown to just search in this thread. Had to look up where to find the search thread feature, not where I expected it. Someday it would be great to compile this into a nicely organized wiki

 

After installing my $100 mobility battery that had 55ah in Jan. 2013, I finally replaced it with this one: UPG UB12550 12V 55Ah 22NF Scooter Wheelchair Mobility Deep Cycle SLA AGM Battery 616913818375 | eBay Sure hope the new one lasts as long as the old one.

 

That 2year warranty and 60-day return policy are really nice, anything else that sold you on that one? Looks about the same dimensions 5.4" wide.

I don't know what T3 terminals are but judging from the photo does the bolt just come out? If so I guess you can just do the same bolt+washer sandwiching trick as before to install the terminals?

 

Yes same threads and washer sandwhich works for this one too.. I bought this one because it was the lowest price and the usual people I buy from at ExpertBattery on Ebay were out of stock of the usual one I buy.

But I just looked and ExpertBattery has finally restocked, so I'll go back to them because they give me an affiliate link to share and I've twice been given about $12 for helping them sell them simply by posting the link on Prius Forums online. So I think I'll go back to this one 12V 55Ah Rechargeable SLA AGM Battery for Wind, Solar, and Off Grid Power | eBay because I'm not too concerned about 2 year warranty considering how little the 12v is used by the car.

 

Thankful for this thread and want to add the specific solution I implemented.
I have been driving with the new battery for about two months now and everything works great. I installed it on a 2017 Prius 3.

After researching different options I found that a "NPP 12V 50Ah 12Volt AGM SLA Battery" is the perfect size for the battery tray in my Prius. It was $115 on eBay with free shipping.

What makes the OEM batteries so unique is that they have a flange at the base which lets the battery be held down by a clamp on the base of the battery. Truthfully I think a good number of other car batteries could be used, but there is not the traditional tie down to secure them. Since the NPP battery is the exact same size I was able to make a custom tie-down. I did this with some 1/4" aluminum rod and the steel strap used to secure contents to pallets (could probably find some in the trash cans of a hardware store). Each end of the metal strap is folded around a 6" section of the bar stock. The trick is to get the length of the strap just right. One of the rods will fit under the fixed flange of the battery tray. Next the battery is added, and the strap is folded over the battery. The other rod is secured by the portion of the battery tray that clamps down to secure the OEM battery. The battery will keep the rods from popping out from under the flanges. The final result is a battery strap that holds the battery tightly to the tray. Not sure how to best word it, but here is a pro tip - after folding the strap around the bar stock, cut the end of the strap off at the center of the strap. This means both ends of the strap will almost touch after being folded around the rods. These loose ends should be pined against the battery because the pressure against the battery, and the bend around the corner of the battery will be enough to keep the strap from coming loose without additional connectors. For easy of instillation, I used tape to keep everything in place until it could be tightened.

For the connectors: The top of this battery have two M6 threaded screws. The top of the terminal has a conductive shoulder. For the negative terminal I made a form fitting washer to clap it in place (see picture). It only took a few minutes on a bandsaw, just leave it connected to a "handle" while you shape it until you get the fit right then cut it off. For the bottom of the negative terminal I added a washer for it to sit on. For the positive terminal, I unscrewed the hoop potion that tightens around a traditional car battery terminal. I then used the bold included with the battery to screw the head of the terminal directly to the battery. Last, as some wise individual suggested earlier in this thread, I put the old terminal connector in a bag and tapped it to the battery.

Battery strap where it is clamped down by the battery platform.

 

Can you please share a link to the battery you bought? Some might be interested in that...

 

Where can I find your affiliate link?

I can report that a VMAXTanks MB96-60 deep cycle AGM battery didn't hold up. Installed one about March 2020 and the ScanGauge is now barely 12.2V when it powers on, on entering the car. Not a cheap experiment, either, at $189.

MB96-60 Deep Cycle, High performance AGM Battery-MB96-60

This was a mice-damaged car (previous owner, cleaned up and sold by dealer, subsequently the light in the headliner failed... long story) so I installed one of those combo strobe/ultrasonic rodent repellers under the hood, which works, but requires having the battery on a Battery Tender Junior when parked at home (outside). The VMAXTanks page for this battery says a maintainer can be used, but I have to wonder if this may have damaged the battery? Anyone else with an AGM battery on a battery tender most of the time?

I'm retired and drive shortish trips 1-2x/week.

Looking to replace with the ExpertPower 55AH.

Edit: Well now, today in 20F degree weather, it's at 12.9V. This is after charging with a Noco Genius in "force mode" and keeping it on that while parked. Maybe it will get me through the winter...

 

Was that measured 12.2v right after you disconnected the AGM compatible battery tender and before you made the vehicle 'Ready' ?

How many hours of actual drive time per week does that equal, as you may not being driving enough. (shouldn't matter with a proper tender)

What is the amperage requirement on the combo strobe/ultrasonic rodent repeller?

Which model # is your Battery Tender Junior, and does it charge at 14.4-14.9V?

After reading the description from your linked AGM battery, this stood out as odd (maybe someone else can chime in) :

* Warning: Do not use a charger with smaller amperage than the recommended Charging Current shown above.
Maintainers should ONLY be used to maintain a fully charged battery but NEVER as a charger.

 

Yes, that's right, and the Battery Tender Junior is supposed to be AGM compatible.

But I'm thinking it might be failing. (I have an older one that was known for capacitor failure and successfully repaired it and have it working on the other car.) I've got the Prius on the Noco Genius2 now, we'll see how that goes.

Oh, certainly not enough, especially now with the pandemic. Even more reason to keep it "plugged in".

It should be about .1 watts, but I need to measure it, and should also measure the overall draw. In the spring.

Deltran doesn't provide this information. However, maybe this is relevant:

TEMPERATURE COMPENSATION (BT PLUS Only): The output voltage is compensated at -3.5mV/ °C/Cell. This increases the output voltage in cold climates to keep the battery from being undercharged and, more importantly, reduces the voltage in high temperature climates to protect the battery from overcharge.

...which may explain why the Noco Genius2 is working better than the BT Junior, now that winter has set in and temps are in the teens F.

BTW thanks for your thoughtful and helpful questions.

 

This is why I will be charging my >300Ah batterybank (off-grid garage) with 13.5V. Right now it is still on a solarcharger, but that will eventually (imho) just kill the batteries.

 

So the Noco wasn't acting right on the Prius, it wouldn't go into maintenance mode (solid green light). The older, repaired Battery Tender wouldn't either (blinking red light). Aha. Bad SAE extension cable. Switched that out, now the Battery Tender is charging (solid red light).

The battery may be good, it does show 12.9-13.0V when I get home from a short trip.

 

Where can I find your HV rebuild?

 

Click on the "Wiki" link in the menu bar at the top of each page. Select the Table of Contents then look for the article below in the 'DIY Maintenance'

Prius High Voltage Battery Reconditioning

I hope that helps.

 

Does internal battery resistance matter? Would a mobility battery's internal resistance differ than that of a conventional starter battery?

I recall watching a video by a tech recommending to not use a different type AUx battery in a Prius because the DC-DC converter would have to work harder depending on the parameters. Can't remember the generation or source or if he was credible. Obviously it would require more energy to charge a larger battery but I unsure about the resistance assertion.

I think it would probably be okay to use the mobility battery on my 2004 Toyota Prius if I replace it again.

Upgraded my battery tray to the SKS size and installed an ACDelco Gold 824R on 1/2019. Exact fit with vent tube. Still works but it drops to 11.4V when on IG-ON and will climb up to 12.2V on accessory. This is true even after use of an occasional external charger.

Thank you

 

I've been using UB batteries in my power sports equipment 20 plus years Honda
Magna v 4 bike various Italian big scooters etc use all time no issues charging on regular 12 V systems in card boats planes etc . Universal battery numbers cover all of em most sealed with no provisions for a vent just like newer HV batts all vents gone my new 09 Hv batt no vents anywhere my old tube penetrates floor just hanging

 

Thank you for the information!