Rated 5.00 out of 5 based on 6 customer ratings
(6 customer reviews)

$39.99

12v 18AH Battery for Mighty Mule FM350 Automatic Gate Opener

SKU: ML18-12211211 Category:
Thumbnail Short Description Price Add to Cart Button
$ 39.99
$ 79.99
$ 159.99
Delivering power when you need it, the Mighty Max ML18-12 12 Volt 18 AH uses a state of the art, heavy-duty, calcium-alloy grid that provides exceptional performance and service life in both float and cyclic applications.
The ML18-12 is an Absorbent Glass Mat (AGM) technology with a valve regulated design, that can be used in enclosed and indoor environments without leaking or maintenance, providing a superior performance for thousands of models.
Mighty Max SLA batteries are utilized in a wide variety of applications including; Consumer Electronics, Electric Vehicles, Engine Starters, Golf Carts, Hunting, Lawn and Garden Tools, Medical Mobility, Motorcycles, Power sports, Portable Tools, Solar, Toys and Hobby, Access Control Devices, Emergency Lighting, Security and  more.  
Specifications: 
Voltage: 12 Volt
Amperage: 18 AH
Chemistry: SLA, AGM
Terminal: Nut and Bolt (NB)
Battery Dimensions:
7.12 in x 3.00 in x 6.50 in
Weight: 11.90 Lbs
Warranty
1 Year
Multi Packs Bundled Savings

1 Pack, 2 Pack, 4 Pack

Volts

12V

Amp Hour

18Ah

Chemistry

SLA / AGM

Terminal

Nut and Bolt

Quantity

1

Length

7.12

Width

3.00

Height

6.50

Weight

11.90 Lbs

Warranty

1 Year

6 reviews for 12v 18AH Battery for Mighty Mule FM350 Automatic Gate Opener

  1. Rated 5 out of 5

    J n L

    I have had the 12v 18ah battery that I use for the FM350 gate opener for about 5 years. I have had absolutely no problems with it at all. We get a lot of rain, a lot of humidity and it basically sits in mud for a lot of the year. It’s small for the battery box it is in. I have the conduit running to the house (not solar). One year I found a half inch of rain/water in the bottom of the box but no problems even then. Now the gate opener is another story. We have a 14 foot aluminum gate (super light!) and for 4+ years we have had to give the gate a little tiny lift virtually every single time we open the push gate. It closes fine. The opener’s longevity considering how much the gate slants has been really good, but even though we followed all the installation instructions AND recommendations to the PRECISE, capital, underlined, bolded T!!!, we can’t get the gate to line up with the locking bracket well enough to open every time. The wood beams are in cement so that’s going to be an awful job to replace the beam(s) one day and for how long will it last the next time. so sad. 🙁

  2. Rated 5 out of 5

    Lisa Poleno

    Works great!

  3. Rated 5 out of 5

    Paul G.

    So far so good.

  4. Rated 5 out of 5

    B. Harold

    as advertised and shipped promptly.

  5. Rated 5 out of 5

    Jerry Woods

    works like it suppose to

  6. Rated 5 out of 5

    Monty L. illiams

    very good product, and was priced competitively

Only logged in customers who have purchased this product may leave a review.

Excellent
Mighty Max Battery
Based on 3474 reviews
Arrived quickly. Even got a sticker with it.
Solid looking battery, came well packaged. Have used their battery before for my lawnmower and now looking forward to see how it lasts in my snowmobile.
I can't believe it less than 48hrs since I ordered from Walmart and it's in the machine. What more can I say except great price.
Thanks Larry
Item as described and perfect fit and arrived on time
Battery arrived in a good shape package strait to my door steps
Arrived just in time to power my generator here in the cold Maine winters. Excellent service!
Arrived quickly from WALMART.COM. Perfect size and proper placement in my generator. Installation was easy. Generator fired right up. Battery came fully charged.
New battery. Ready for cold weather!
So far these Might Max batteries are good but it’s only the first day and they were on charge for 12 hrs. I’ll have to come back and do an update at some point in time. Ordered them on Amazon and got them the next day. I was encouraged by Mighty Max to make this google review and post pictures to extend my warranty for 3 months but there is no way to post pictures 🤣🤣🤣 It’s been a few months and I was able to go back and edit, so here is a video I made, the rest of the photos I have deleted. Batteries are still going strong. Update 12-11-2025
They arrived within 2 days of ordering them packaging was really good I haven't put them in my MX350 yet I hit them with my multi meter fresh out of the box and got 12.4v on both batteries so that is good