Battery Drain - Observation

Question

About a week ago I decided to try a little test on my TT. I have two 6-volts that are my main batteries for my coach, but I also have a "refurb" 12 volt used as a back up. I charged the 12 volt to a reading of 12.87, connected it to the TT for a period of 4-days & checked it each day. Now, keep in mind I have no idea of the 12v battery amp capacity, so that's an unknown. Over the 4-day period, the battery went from 12.78 to 12.17. Nothing is on in the coach with exception of the LP sensor & anything else that may draw power + possible parasitic draws.

Even though the 12v is a "refurb" & I checked it with a hydrometer & it checks out as good.

I may be wrong, but doesn't that seem like too much draw down in that period of time under the circumstances ?

jrs___b · Answer

Sounds normal to me, especially if you did not flip the battery disconnect switch. I put my trailer in storage after a 1,200 mile trip from Florida back to Michigan. So the battery was fully charged. I forgot to flip the disconnect switch. When I came back a week later the battery did not have enough power open the slide-outs.

Plus, the 12.78 reading would have dropped some just sitting on the workbench for 4 days.

the_bear_ii · Answer

X 2 Sounds normal

2oldman · Answer

Dakota98 wrote:t I also have a "refurb" 12 volt used as a back up. I charged the 12 volt to a reading of 12.87, connected it to the TT for a period of 4-days &amp; checked it each day.... Over the 4-day period, the battery went from 12.78 to 12.17.Try it with the battery attached to nothing.  It may not be the trailer at all.  An old battery will not hold a charge.

sandia_man · Answer

You started out with maybe 80 amps and went 4 days or roughly 96 hours, sounds normal with the parasitic draws of most RVs. Remember the 12.87 volts you saw is surface charge, in reality without anything hooked to it would have dropped to about 12.6 volts.

Without knowing the true condition of the refurbed 12 volt battery I would say that it did pretty well all things considered. A single battery is really only good for a couple of days of camping off the grid and that is with sparse use, it's the main reason why many go with at least a pair of batteries to get them through a 2-3 day weekend.

prichardson · Answer

Sounds normal; especially on newer RVs.  If you have anything that is remote control it is never completely off unless it is disconnected.

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Battery Drain - Observation

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