Bill Roper's Journal

It doesn't sound like the battery to me. If, when you try to start it, then it turns over briskly as normal then it's not the battery. If it's very sluggish sometimes but then starts as you seem to be saying then I'd suspect the high current wiring between the battery and ground or to the starter motor via the solenoid or maybe from the alternator/regulator.

The very rough running could be low volts - but it could also be some other problem like too rich a mixture caused by something wrong with the engine management system.

If a new battery does fix it then I'd be on the lookout for a charging problem (alternator or regulator) or once again the high current wiring to the battery. There have been cases in the past of leads where the lug was crimped *over* the insulation rather than having it stripped off first!