Battery dies overnight on Craftsman.

[JDTank]

In-Laws have an old 19.5 HP B&S Turbocool riding mower with a 42 inch deck.

Just recently it has started to die overnight. You boost it the next day, cut your grass, and if you stop it and restart it within a few hours, if your doing random work, it will start because the charge is still there.

I tested for a parasitic draw this afternoon. It came back with 0.03 MA. Is this enough to drain the battery? My thinking is there shouldn't be ANY draw because it's a riding mower. It doesn't have a radio clock or security system like cars do that need constant power to remember settings. It only has the front lights which I wired on a new circuit and switch myself 2 months ago, because the terminal for lights on the factory key switch is dead, must have broken inside. I already checked my circuit I made for the lights and it is not the issue. I get the same parasitic draw with my circuit hooked up and disconnected.

I noticed there are two wires running to the front of the engine by the carb. I know it has a vacuum fuel pump so what could this be? Solenoid? I haven't checked these yet because I forgot to, and the weather has turned severe here, warnings in place! :dance1:

My guess is the key switch must be drawing power.

Can I replace it with just any car key ignition switch from a hardware store? Does it HAVE to be a craftsman switch? I know my local Canadian Tire sells ignitions with 5, 6, 7, even 8 terminals, including two keys, meant for older cars. I figured I could just buy one of those and pop it in there.

Thanks for the help!

 

[Deere Dude]

Are you sure it's not the battery? I would have that tested to make sure there's not a dead cell.

 

[BobRip]

0.03 ma will use 1/2 of the capacity a 50 amp hr battery in 34,722 days. I don't think this is your problem. Checking this is a good idea. What is the battery voltage when cranking? It should stay above 10.5. The voltage while the engine is running should be about 14 volts. With no charge or load it should be around 12.6. Take the battery to Advanced Auto Parts right after running and they will test it. I suspect a bad battery. Cranking a hot engine with a hot battery is easier than cold cranking a with a cold battery. Of course look at your battery terminals.

 

[BobRip]

Are you sure it's not the battery? I would have that tested to make sure there's not a dead cell.

Very likely.

 

[creekbend]

I have a Craftsman riding mower like the one you are describing except it has a 18.5 HP- B&S engine. 4 months ago, the battery was dead when I started to mow. I used the battery charger and finished mowing. The same thing happened the following week. It ended up being a dead battery. I put the new battery in and the mower started right away. The old battery was 6 years old. Best wishes.

 

[JDTank]

Sorry guys I forgot to post I already checked all of that stuff, trust me, I am very mechanical, I wouldn't post this without having some information haha.

Battery shows 12.2 volts not running. Running it is charging at 14.3 volts. I can't remember the cranking voltage, I wrote it down but damned if I can find it now.

The only reason I ruled out the battery, again, I forgot to mention, is because it was brand new 10 months ago, and it was trickle charged throughout the entire winter to save it.

My father in-law, who isn't mechanical, picked up the battery a year ago, and he did not have it load tested at that time. I always stress to people, you don't know if that battery has been on a shelf for 2 or 3 years with no attention given to it. Needless to say, It likely is a bad battery.

The trickle charger they bought was a cheap $20 plug into the wall deal. I am guessing it did not have the ability to sense when the battery was full, and likely overcharged it, ruining it now.

While we are on the topic, what is the BEST charger to use for long term battery storage? Every year they leave the battery in the mower, all winter. It doesn't get cold here, but still, it isn't being looked after. They buy a new battery every year because to them it's cheaper than a charger. Crazy!

 

[BobRip]

I am using a Deltran Battery Tender. I have one on the Power Trac and one on my trailer. I like the way the LED indicators work. You can tell if the charger is getting AC and the battery condition.

Leaving a non regulated charger on a battery for months will ruin it.

 

[BobRip]

In my life I have bought two batteries that I did not test when purchased that we're bad. Always test prior to purchase.

 

[DieselMonk]

The only reason I ruled out the battery, again, I forgot to mention, is because it was brand new 10 months ago, and it was trickle charged throughout the entire winter to save it.

That means squat. My brother had the same problem and new battery went flat in short amount of time. First, make really sure you got a good battery with charging it and a load test. Make sure the battery is dry, not wet on top between the two terminals (another parasitic drain that flattened a battery before), now you are sure the battery is good. Next unhook the positive terminal from the battery and mesure the current flowing with a VOM between the battery and the battery positive terminal (that goes to the starter module). The negative terminal is hooked up to the battery. We fixed it by installing a 30A on off switch. Was cheaper than buying a new $80 module.

 

[DennisFolsom]

As batteries get old (or otherwise damaged), they can develop internal shorts. The machine can be boosted or charged, and it will start up ok. However, the battery can drain itself from internal shorting overnight.

I'm not saying it's not a good idea to have a battery tested where you buy it. However, if you buy in Wal-Mart, Sam's, or some other big-box store, you will probably get it enough cheaper that you can afford to take a chance on it. Also, these places will usually give a refund if you find the battery is bad and bring it back promptly.