Alternative 2nd Stereo Battery Solution?

[nohassle5]

I have a 98 speedster without a factory stereo. After 2 seasons without tunes, I’ve finally decided to drop in something. I’m planning on dropping in a head unit, 4x6.5's, and a couple of 10” subs with an amp. Instead of wiring everything to the main battery, or adding a full size second battery and switch (as RFoster and others have done), would it be possible to put an isolated smaller motorcycle/lawn tractor battery just to power the stereo? I already charge the main battery between uses, so another battery on the charger wouldn’t be an inconvenience. Has anyone done this? What grounding issues would I need to concern myself with?.....
Ready for the onslaught.
Thanks for everyone’s input in advance.

 

[the big e]

A motorcycle battery would last about 8 minutes with the stereo your planning to put in. Motorcycle battery 12AH, marine battery 100AH. Also normal batterys dont take to well to being drained and charged, drained and charged......

 

[RFoster130]

Yeah it wont last. It really is much easier than you think. It takes less than 2 hours and under 200 bucks. Find the thread i did and it has everything you need.