Battery Voltage question

[Whopper Stopper]

I have searched the archives and can’t find an answer to a battery question so I will ask it here.

I have an o9 Grizzly 700. The battery is original, and seems to start the ATV just fine. I mounted a Hummin Bird 788 on the ATV. The 788 is a little touchy to voltage drop. What I have found happening of late is when on a lake when the temp are cold the 788 keeps turning off.

The battery when in the garage shows 11.5 volts. Does anyone know what the voltage should be from a battery in good condition?

I am guessing when outside the voltage is less than 11.5 (have not tested that yet) and as a result when driving on the lake the 788 keeps shutting off. I wanted some feedback from you people before I just go and drop $100.

Thanks as always for any tips or comments.

WS

[merkman]

[Walleyehooker]

Sounds like you have a bad cell. At full charge it should be 12.6 or better. 2.1 per cell X 6 = 12.6

[efgh]

It looks like your battery is on the way out. You can put a charger on the battery to see if it comes up to 12.6 volts, maybe something is wrong with the charging system on the 4 wheeler.

[Whopper Stopper]

Thanks a lot! Much appreciated!

Should I be looking for any certain brand? The one that is in there is a Yuasa YTX20L-talk.

WS

[merkman]

Make sure to check the battery when totally disconnected from the machine to isolate anything dragging the voltage down, if you still read 11.5 volts at full charge. Take the battery to an autoparts store, they can load test it for you for free.

.

[Whoaru99]

If the battery reads only 11.5V after charging and allowed to stabilize, there isn't much point to get it load tested.

You can also check the charging voltage. Don't know the exact spec. for that machine but typically, the voltage on the battery with the engine running and revved up should be something on the order of >13V and <15V.

[Whoaru99]

Thanks a lot! Much appreciated!

Should I be looking for any certain brand? The one that is in there is a Yuasa YTX20L-talk.

WS

That is a good brand of battery.

[panolo]

YUASA are very good batteries. The only other MF battery I would use is a Interstate. The machine should put out about 13.5-14.2 volts. 09' Grizzly 700's had a different crankcase cover than 07'-08' that holds more oil for cooling the stator. I have never replaced a stator or reg/rectifier on a 09' and newer grizzly.

Also one thing I see folks do with batteries is always keep a battery tender on the unit. Not a good thing unless your charger has a desulfation mode. A smart charger like an Optimate or Ctek work much better.