Battery

[precorguy]

ok, i know this has been done - but i just don't really get it --- i am looking to replace my sunline battery ---- i know that 2-6V is better or so i hear - but i seldom camp without electricity - actually only once per year - so for the sake of keeping expenses down, i am looking at a single 12V

so, what is the difference - simply put, between group 24 and 27 - does a group 27 give me a bit more power - i know that i will need a large battery box.

for one weekend use - can i use both my existing 2 year old 12 V and a new battery without doing any major damage --- i am going to move the smaller 12 V (group 24 i think) to a back up sump pump when i don't need it for the trailer.

i have a 4 day camping trip booked and it looks like i will need the power - its for the fridge, waterheater electronics, water pump and a couple of lights that are seldom used and the fantastic fan which i need to keep her cool inside - since i am in the sun with no shade --- i want to make it through - last year i was 3 nights a well the last day was dead battery - luckily after my morning shower!

thanks
alex

[JohnB]

Hi Alex

If you are only doing off the grid 4 days a year it is hard to justify getting big amp hour batteries and never use them.

Yes a Group 27 has more amp hours then a Group 24. Pending brand this moves around a little. This may help some http://www.marxrv.com/12volt/12volt.htm

Pending brand a Group 27 might be 20 to 25% more then a Group 24 in storage capacity.

However if you do not have a good desulfation program for maintaining your batteries regardless of size you will not get everything you can out of them. You can get one of these for about $45 shopping them on the web. Read up on them and use them all the time when not camping. Just disconnect the leads form the camper http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Plus-12-Volt-133-Amp-Charger-Maintainer-Conditio-p-16134.html

Check the water level often. 2 to 3 times a camping season if you have a good charging system to not boil out your battery.

A well maintained battery that is desulfated will give you all it can. Being a power mizer then extends the battery time. Lights can be a killer in battery power and not realize it. The standard RV light bulb a 921 draws 1.3 to 1.4 amps each…. Changing light bulbs goes a long way. If you have the $$ LED’s can give as much light at 0.235 amps each. Even lower output incandescent bulbs draw less.

Go on a power hunt in your camper for things stealing power you do not use. The TV antenna, the radio, the HW heater when you are not even there.

I would not mix your 2 year old non desulfated battery with a brand new one. But you can buy the Battery Minder and condition it, maintain it and bring it back to as close a life as it has. The a 2nd battery is a back up. Get a volt meter even if from Harbor freight and when the voltage gets down to about 50% discharged, then swap and put the new fresh battery in. They can both be in the battery tray just not hooked up. You do not harm the new one and the old one gives good service.

For a once a year 4 day trip, 2 well maintained Group 24’s being power stingy can cover you in the summer.

BTW the battery Minder can do 2 batteries at once if they can be placed next to each other in parallel.

Hope this helps

John

[precorguy]

Jon

thanks - so i should just stick with a group 24 and do as you mentioned - kick off things like the hot water heater when not needed - i don't use the radio or the tv when camping so that is no issue.

i think i will go with your suggestion - carry the two batteries and use one for one day or two, then switch it out for the second one while i charge the first one = then back again if needed ----- good idea!

yes, i have been looking at the battery minder - perhaps my christmas list (gosh i hate to say that already)

thanks!

[JohnB]

Yes if you are only using dry camping 1 weekend a year a pitch hitter battery will work.

On the radio, you have to pull the fuse to stop if from draining power

Good luck

John

[pwb01]

I ruined 2 batteries in two years because I didn't check the water often enough. Also, I've been told by several people including dealers that if you use two batteries, they need to be the same size and rating, I don't know why. I hook up two permantly and add a third for 5 daays or more.