Battery went bad but now is good?

[bdog]

I have a 2015 RTV I bought new. Two of them actually. The battery went bad a few months ago on one that we use several times a week and I replaced it. Figured it was about time being seven years old.

The second UTV I don’t use as often as it is kept at a remote property one hour away. The battery on it started getting weak a year ago and every time I use it I have to jump start it. I use it so infrequently I just have lived with this. One time we jump started it and ran it for about four hours without turning it off and tried to restart and it wouldn’t. This has been repeated maybe 5-10 times - jumpstart it, use it, try to restart and it won’t.

Anyway today I jump started the machine and ran it for maybe thirty minutes without shutting it off and loaded it on a trailer to bring home so I could replace the battery, change the oil, etc. i drive an hour home and when I got here I tried starting and the machine fired right up. It was cranking over fast. The battery is seven years old I am sure it needs replacing but how did this happen? I checked the connections a while back and they are clean, good, and tight. How does a battery refuse to take a charge ten times in a row and then all of a sudden does?

 

[jaxs]

You either missed a bad connection when you checked or origional problem was from bad connection between battery cells that temporarly made connection while riding on trailer.

 

[Richard001]

Could be a lot of things.

-Bad starter solenoid
- poor battery ground on the frame or to the engine
- Starter has a bad armature winding or worn brushes
- faulty off/on/start switch
Have you checked the battery voltage when the engine is running ? Should be around 14.5 VDC.
After shutting off the engine and waiting a half hour, measure the battery voltage, it should be over 12.6 volts.

 

[Gem99ultra]

I've found that an old battery that's close to dying can be charged, but it won't hold a charge for very long. It'll loose it's charge within about an hour after shutting off the charger or other charging sources.

The best way that I've found in determining the health of batteries is with my little cheap hydrometer. No doubt, a load tester would be better, but the hydrometer will give me a heads-up.

 

[jaxs]

I've found that an old battery that's close to dying can be charged, but it won't hold a charge for very long. It'll loose it's charge within about an hour after shutting off the charger or other charging sources.

The best way that I've found in determining the health of batteries is with my little cheap hydrometer. No doubt, a load tester would be better, but the hydrometer will give me a heads-up.

You are correct on all accounts. Variation from cell to cell in specific gravity while using a hydrometer is a sure sign battery is going/gone bad. Usable life of batteries that aren't used daily and/or on vehicle with less than perfect charging system can be extended with routine use of smart chargers. Even when new,lawn tractors and outboard engines have poor charging systems. Battery life will easily double if kept on smart charger while not in use. "Kept on" doesn't neccessarly mean 100% of time. 1-3 days out of every month is 98% as effective as every day. Each day a battery sit's less than 100% charged shorten's life. Quick charge is hard on batteries and should be avoided when possible. Boosting a discharged battery then charging up from vehicle is a form of quick charge.

 

[SandburRanch]

Yes , batteries can be intermittent . I had one that would crank and not crank and a co-worker had one that would fail often but not always when a left turn was made . Sure glad the problem isn't prevalent .

 

[Skagit]

Yes , batteries can be intermittent . I had one that would crank and not crank and a co-worker had one that would fail often but not always when a left turn was made . Sure glad the problem isn't prevalent .

That's not how batteries work, you're describing connection problems.

 

[SandburRanch]

That's not how batteries work, you're describing connection problems.

I'll agree , internal connection problems .

 

[Richard001]

You are correct on all accounts. Variation from cell to cell in specific gravity while using a hydrometer is a sure sign battery is going/gone bad. Usable life of batteries that aren't used daily and/or on vehicle with less than perfect charging system can be extended with routine use of smart chargers. Even when new,lawn tractors and outboard engines have poor charging systems. Battery life will easily double if kept on smart charger while not in use. "Kept on" doesn't neccessarly mean 100% of time. 1-3 days out of every month is 98% as effective as every day. Each day a battery sit's less than 100% charged shorten's life. Quick charge is hard on batteries and should be avoided when possible. Boosting a discharged battery then charging up from vehicle is a form of quick charge.

While this is good advice, if the user is away from the unit for months at a time, and 115V AC power is available, the purchase and use of a battery tender would be more appropriate.

 

[jaxs]

While this is good advice, if the user is away from the unit for months at a time, and 115V AC power is available, the purchase and use of a battery tender would be more appropriate.

I confess to being vague. Personally I've used Deltran brand Battery Tenders for many years. When I specifically reccomend Deltran,people usually chime in to sing praises for Harbor Freight and other units that sell much cheaper. I've come to except getting people to use anything with slow,tapered charge an accomplishment but not arguing that el cheapo chargers are not as good as can be had. Maybe you can try convincing people all tools aren't the same or as the saying go's "you get what you pay for".