Battery good, but only starts with jump

[taxguru]

Craftsman 4500. 24 hp Vtwin. 42" deck. 7 years old. About 380 hours. I change oil, filters, spark plugs, etc every year. Last year had Sears come change deck belt and 1 bad spindle. Buy new battery every spring.
Bought new battery end of March. Mower started off battery. Did not mow in April because no rain meant no grass. Finally went to mow 2 weeks ago and would not start off battery. Started off jumper and ran fine for an hour. Turned off. Attached spreader. Would not turn on off battery. Started off jumper. Spread. Back into shed.
Last week I hooked the battery up to charger so it would be ready for weekend. Weekend comes, time to mow again. Voltage meter said 12.9 volts. Put battery in mower, will not start off battery. Remove battery and go to store where I bought it. They say battery holds charge fine. Go home. Top off battery with charger for an hour. Back into tractor. No good off battery. Starts fine off jumper.
So do I need a new starter motor? Check for bad wiring? Check for winter debris under the engine housing?
Or maybe just bite the bullet and buy another battery and keep this one charged between uses?
Much thanks for any suggestions.

 

[mechanic mark]

Post tractor model number from under seat, engine manufacturer and all numbers, model xxxxxx, type xxxx, code xx. Check all wiring and connections for corrosion, rust, sheathing missing from wire {bare wire}, wires chafing and all connections are tight, especially ground cables and wires from engine to frame and chassis, also wire harness plugs to ignition switch etc.

 

[Carscw]

Have you checked the valves?
Will the engine turn at all with just the battery?

 

[tomsteve]

battery holds charge fine, but was a load test done?

 

[motoman]

Load test yes, or use hydrometer on cells. Trickle charge the batteries year round and they will last 3 years.

 

[Fish]

Adjust the valves first.

 

[taxguru]

Model = 917.287260. Today would not start even with a jump. Solenoid clicks but starter does not turn. Heavy cables from battery to starter solenoid and from solenoid to starter motor seem fine (under red plastic housing, not dirty). Multi-connector to ignition switch was dirty. Cleaned posts and connector. Still no go.

Guess I will have to get out my voltage meter and see how far power is getting through the circuit.

Then maybe go get another battery that never got down to zero charge (I do not know how to do load test). Trickle charging the battery is a pain (mower lives in shed in yard with no electric, so have to remove battery and bring to garage every time). But this is worse.

Thanks for any other suggestions.

 

[exotion]

Man electrical problems suck. User rivets has a fantastic electrical trouble shooting guide pm him

 

[taxguru]

So it did not start when jumped with the "plug in the wall" starter / charger, but it did start when jumped with the portable jumper / light / tire inflator. So at least I got my lawn mowed.

I guess maybe the problem is that the battery charger is too weak. Any suggestions for who makes a nice wall charger / starter before I head off the Harbor Freight for the cheapo option?

 

[exotion]

I personally have had good luck with the harbor freight cheapo