Forum Discussion

Nomad II

Mar 08, 2016

Battery Half-Life

I know there are some people that are knowledgeable in this cause I think I have seen this answer before. But if I have a fully charged battery, zero draw on it, an average temperature of about 40F, how long will my battery last before it gets to about 50 percent. I ask this because I just got a new battery in my TT, I fully charged it, I don't really want to take it out at this time if I don't have to. The TT will be going to the storage yard and I won't be using it for about 6 weeks. I have a disconnect switch so it will have zero power draw on it but I would prefer for the battery not to discharge to less than 50 percent. Average temperature here will probably be around 40F to beginning of May. I will be using it May 12. Any thoughts?

15 Replies

red31
Explorer
Mar 08, 2016

From Johnson Control marine battery info 2004
RoyB
Explorer II
Mar 08, 2016
My batteries sit disconnected in my OFF-ROAD POPUP over the winter months. They start out at 12.6-7VDC... I typically see around 12.3-4 when I bring them back to life in the spring. A 12.0VDC reading for me represents the approximate 50% charge state.

I will look at the batteries at least once a month and can do a normal re-charge then if necessary...

Roy Ken
pianotuna
Nomad III
Mar 08, 2016
If the battery is old as the hills 1% per day. If it is new 2% per week. If it is AGM self discharge rates are less.
RJsfishin
Explorer
Mar 08, 2016
Make sure there is no draw bypassing the battery shut off,......preferably remove a battery cable, and it will be fine.

But better yet, connect a 60 watt solar panel to it.
westend
Explorer
Mar 08, 2016
Typical flooded battery, you will lose maybe 20-30 percent at 40f in a month+. Typical AGM, 5-10 percent in that same time.

BTW, I wish the administration of this website would allow the use of the percent symbol. It is ridiculous to set the formatting to exclude it as hackers aren't going to use it in a hacking attempt.