Battery charging questions

[Trev]

</font><font color="blue" class="small">( Yes it's normal, I have a battery tender on my 790 John Deer tractor and it charges after it has been running. It goes off within an hour.
mainiak1 )</font>

Oh, interesting.. mine took more than an hour before it was back to a solid green light.. but it's good to know that I'm not the only one. I'll just run it for a while and see what happens. Next time I fire it up, I'll also see what voltages I'm seeing at the battery terminals.. but it must be charging to some extent or that old battery should have died a year or so ago...

Thanks,
Bob

 

[Jeff396]

Hi Trev,

My Battery Tenders always show red when hooking them up after running any of my vehicles. I have not noticed how long it takes to change from red to green though. I've had the one on my T-bird for about 4 years and have yet to have the car fail to turn over briskly.

Jeff

 

[Trev]

</font><font color="blue" class="small">( Hi Trev,

My Battery Tenders always show red when hooking them up after running any of my vehicles. I have not noticed how long it takes to change from red to green though. I've had the one on my T-bird for about 4 years and have yet to have the car fail to turn over briskly. )</font>

Thanks, Jeff... good to know!

Bob
Jeff

 

[ZJ_HR]

Bob,
It's easy to see current flow, even you don't exactly know amount of Amperes.

Connect your + (red) measuring stick on minus (-) pole on battery, and - (black) measuring stick on end of grounding cable (where it is bolted to tractor chassis). Then set your digital multimeter (DMM) on DC mV range.

Turn lights on - DMM will show (-)XXX mV, because you draining battery. (If differet, replace places of sticks).

Then start engine. Check on idle, and then on higher rpm. Normally in both cases, it should be (+)YYY mV on display.

As you don't know resistance value of grounding cable, you can't measure exact amperage, but it will help you to troubleshoot failure in charging circuit. /forums/images/graemlins/wink.gif

Voltage of good, full charged battery is about 12.4-12.6V, before starting engine and with no load.
When you start engine, voltage must increase up to 14.4V, with no load, as Bird mentioned before.

Hope this helps,

ZJ

 

[Trev]

Thanks ZJ, and welcome to the forum!

Yes, that helped!

Bob

 

[ZJ_HR]

Bob,
Thanks for welcome. Tractors and farm machinery is my big "love".
I have some experience with tractors electrics, like repairing alternators, starters etc, so if you need some help, drop me a message. I'll be glad to share my knowledge to help you or somebody else. /forums/images/graemlins/smile.gif

ZJ