Going to be using the boat motor or inflator for several days and want lots of extra power to run then? Or maybe you won't have excess to electricity for recharging the ones you have? Whatever the reason you need "More Power" Sevylor's Rechargeable 12V battery with 110V charger for Sevylor motor, inflator, etc. is what you are looking for.
Comments about Sevylor Sevylor Rechargeable 12V Battery with Charger:
bought this battery not having a working knowledge of batteries and their performance levels. i have now turned this battery into a back-up (because the small size allows this)