Should not be any problem at all if you are doing a direct swap. Are you trying to have it in your car only for charging? Say, a place in the trunk? If so, then you will need to make sure your alternator can handle the extra load, you will also need to make sure it is electrically isolated from the rest of the car electrical system. Or you could just buy a trickle charger and have it in the house; with adequate ventilation. Also, a single small solar panel would do the job.

2 cents