I was going to the first reply to the original post thinking that perhaps 1350 mah was a tad short. If it were me, I'd go for at least 4000 mah and probably four cells with a good C rating. But, that could be a tad bit more expensive than a replacement 12 volt lead-acid or gel-cell pack.

Jose, that must take at least a couple hours to recharge??

CGr.