Nautilus Battery Pack for Boat

[Gotrain44]

In Canada local store has a Nautilus Battery Pack on sale. Add says 800 crank assist and 33 amp hour deep cycle battery. What I like about it is it has a built in inverter and has 2 - 120v outlets a 12v outlet and jumper cables. I was thinking I can use it to power my XM radio on the boat and also boost the boat battery if needed. Some bad reviews though that battery in unit has died in about 1 year. Any thoughts? I can get it for $165.

 

[Nike12000]

I know on skis your not suppose to jump them when connected. not sure if the boats are the same but can mess up computers