Battery Charger and electrical line loss question.

[Moon]

I have to use 200' of electrical cord to get power to my pole building. Last winter I used battery tender swaping it between two seperate batteries. The batteries were not charged up come springtime when I tried to use them.
Recently I had a tractor battery go bad, and I tried to charge it while still in the pole building via 200' of extenstion cord. No good. Did not work.
I thought I did something wrong with the battery tender last winter , but could this be because of the distance / length of the cord?

Thanks,
Moon of Ohio

 

[WhiteRock]

If a battery tender is all that you have on the line, I don't think that is the problem. A battery tender will not draw much current and will create very little voltage drop.

Some battery tenders will not charge a battery, only maintain them. So it is very important to start with a full charge.

 

[Moon]

That is what I thought. Battery Tender (Plus) that I have should not pull that much current.
The batteries might not have been fully charged to start with.

But a standard battery charger did not charge a practically new battery (the key was accidently left on and drained it dead). Thats what made me think of a line loss issue.

 

[DUMBDOG]

200 feet of extension cord, but what size is the wire?

How many amps is the battery charger?

From this additional information you can go to a voltage drop calculator and figure the loss of voltage.

For example, 200 feet, 18 gauge wire, 6 amps will yield a 16 percent voltage drop.

 

[SPIKER]

unless you were running a BOOSTER on HIGH AMPS the loss should not be an issue here, you may have a dead cell though or dead charger, you need a ampmeter or DOM to test the battery & charger to SEE if it is working also to test the cord for good connection and power levels of AC out there...

MarkM

 

[BB_TX]

<font color="blue"> (the key was accidently left on and drained it dead). </font>
I think some battery chargers have a protection circuit that will prevent them from charging into a completely dead battery. If it can detect no voltage at all, it assumes the battery is no good. Some others may pulse the dead battery until it begins to show a voltage and will then start a normal charge.

 

[Moon]

The extension cord was a couple of those 100' orange ones they sell at lowes. Probably 18gauge. Don't know what the battery charger pulls amp wise, but the battery tender would be a lite load I'd guess. From the responses I probably was dealing with a couple of other issues instead of just line loss.
Thanks for the thoughts!

Moon of Ohio

 

[btolle]

Go to Voltage Drop Calculator and plug in your numbers and it will tell you how much voltage you have at the end of the wire. You need to know how many amps the charger and anything else you have such as light bulbs on the end of the cord.

200' of 18 ga. cord is not good for much amperage.

For instance, if the total load is 5 amps the voltage will be 104.1 volts if the supply is 120 volts. 13.3 percent drop.

The transformer in the battery maintainer is not power regulated. If it is supposed to put out 14.7 volts a 13.3 % drop would be 1.995 volts. If this is correct you would only be getting 12.7 volts which is not enough to charge the battery.

Easy solution: Move the batteries closer to the house.

Bill Tolle

 

[BB_TX]

Either tow the tractor to the nearest outlet or pull the battery and take it there to eliminate the extension cords. Then you will know whether the problem is the cords, the charger, or the battery.

 

[WhiteRock]

In my opinion, there is a little to much focus on the extension cord.

I am not to familiar with batteries that are put in tractors these days, but running today's batteries totally dead can cause permanent damage. Often a cell will open, not short, resulting in no current being drawn by the charger. Not much you can do in this case but get a new battery.

I agree that taking the battery in for a full charge if it will take it would be the next step.

Extension cord: AC line current DOES NOT EQUAL charger current.

Maintainers usually use 300 - 500 mA to maintain the voltage level, and this is often not constant. Any more may boil the acid out of the battery. So let use 13.7 VDC for the maintain voltage. If we want the AC line amp, we need to convert to watts. So 13.7V X .5A = 6.85 VA or watts. Now lets take 6.85 watts and convert to amps at 120 VAC. That would be 6.85VA / 120 V = .57 Amps.

If you plug .57 Amps into you voltage drop calculator I think you find that you can run a pretty small extension cord.

Now, if you do anything that gets the amperage demand up, then the concerns are valid.

I hope this helps.