Battery Life and Low Temps
I have been having a ball up at Iris Meadow off of Rock Creek Road, Close to Mammoth Lakes, CA. It's the steeper side of the Sierras just East of Yosemite. It's a little known area comparably, but v...
Forum Discussion
Rmack1 wrote:ktmrfs wrote:
cold temps are a double wammy. first, you likely need more furnace, second battery capacity drops with low temp. Don't recall the exact numbers, but by 0F battery AH capacity is down something on the order of 30% or more.
One light on the battery indicator is really low. However, the question is why did the batteries get this low?? Low temps reduce capacity, but unless other things had been drawing current, the furnace should have worked.
I think I know how my batts got drained.
I've been a fan addict for most of my life. They provide cooling in warm weather and white noise anywhere. We use them with vent and window configurations to ventilate our TT. In the mentioned weather, I slightly crack my head vent at the back of the TT, and open the small starboard window next to me in the Murphy bed. A 12 volt fan hooked on the big divider drapes when I'm on batts, or a small desktop fan when I'm on full hookups provides the circulation.
The thing is; the two 12 volts always worked with plenty left over with the 12V fan going all night. When it was lots warmer.
I'm a SoCal tread trash. I'm ignorant of low temp operating protocols. I learned something this trip, I think.
Note that from the graph above, battery capacity in AH is down by almost 40% at 0F !!! So, as an example a 100AH battery has a capacity of about 60AH at 0F. Now suppose that the 100AH battery was discharged by 40AH in "normal overnight temps" to a 60% SOC, not bad. Now in cold that same 40AH discharge is basically completely discharging the battery, taking it down to 20AH and 20% of capacity. BAD BAD BAD
