Paquete de batería Liftmaster K74-30762

This is a kit comes with the correct batteries but with the wiring for other models. The single battery for the LA412 is this: https://elitegates.net/products/liftmaster-mbat-battery-for-gate-openers

Hello Andy. That will depend on the system you have. Some systems are 12v and some are 24v. Normally when people buy this product they simply wire it they way that they had it before since it's not a new installation. If 24v you will have a (+) from one battery and a (-) from the other go to the motherboard and then you bridge between the two remaining battery terminals.