It absolutely depends on what kind!
There are dozens of different kinds on the market.
Many folks here use the battery tender brand.
The battery tender Jr. costs about $25 and it will keep your
battery fully charged and not boil off the electrolyte.
Harbor Freight has a knock off version that's in the $10 range.
I have a couple of each and am happy with both kinds.
I use them on my motorcycle in the winter, my riding lawn mower,
my truck which is not used much in the winter and my trailer.
I have found that they all stay charged and do not use water any
more than normal.
If you use one of these you can top up your battery with distilled
water and it will be OK for 5 months.
You also want to be sure nothing is on in your trailer!
LP detector and even the onboard power center will suck your
battery dead unless you pull fuses or have a battery disconnect
Other chargers and YMMV!
Dan & Rita D
2004 5.3L Silverado 1500 ext. cab 2WD
1999 Suzuki Intruder Motorcycle
Blue Ox WD hitch, AirLift load levelers
Camping days 2010-53, 2011-47, 2012-41,
2013-41, 2014-31, 2015-40, 2016-38