Neptune Brand NT485LM Replacement Battery for Chamberlain LiftMaster 485LM 4228 41A6357-1 3850, 3850P and HD900D Battery Compatible with Backup - Equipped Garage Door Openers…

Fit perfect as replacement for garage door opener, and the tool is a nice bonus

Works great, plugged right in and fully charged the next day for usage when the power went out again.

This nice money saving back up battery is perfect. It was easy to install, much cheaper than the requested battery from the garage door opener manufacture. I am very happy with this purchase, job well done guys.

So the price is great and it does work but I did have to cut away some of the excess plast near the positive port to expose enough of it to catch the wire on my garage door opener.The red cover is not seated properly and there is/was excess red plastic as stated above. Not sure if I would buy this product in the future due to poor craftsmanship

This battery fit perfectly in my garage motor and most importantly stopped that irritating beeping!

Battery was easy to install. Works as advertised so far. I'll have to wait to check the longevity of the battery

This was a great replacement at a lower cost.

Purchased this item to replace the original battery in my Chamberlin opener that was installed in 2014. Item arrived well packaged and in good condition. Make sure you turn off the circuit breaker or unplug the opener BEFORE starting work ! Instillation was very simple, took about 10 min. My model required the removal of a small cover which is held in place by a Philips head screw. Take a rag or paper towel up to the opener with you so you can clean out any bugs. Since I have 2 openers installed at the same tome, I replaced both of them even though one had failed.