Chapter 29 - Hot Lead? OK, Warm Lead
Friday, January 09, 2009
Winter blows in. The temperature drops. Lead batteries grow weak.
Lead-acid batteries deliver their maximum power at around 78F degrees. As the temperature goes down, power output goes down. Time to power up all those heat strips I put in the bottom of each battery box, some months ago.
The same 110 AC that runs the battery charger will power these heat strips.
A small thermostat is needed to control the heat strips. In the photo above, the red arrow shows the heat sensor, and the yellow shows the temperature adjustment knob.
Dave P. gets me three thermostat modules, one for each box. Once these were wired in place, I adjusted each thermostat so that the batteries would be warmed up to 79 degrees, but no hotter.
I made clear plastic tops for the thermostat boxes, so I could see the red indicator light.
Unfortunately, testing showed that the light could be on even when the heat was off. This problem was solved by using a small watt meter to see how much juice the battery heaters were using. If all the heat strips were on they would using about 350 watts.
If only one box was being heated, the meter would show around 125 watts, as in the photo above.
Now on to the next chapter!