Deep cycle battery maintenance

[rvshrinker]

Hello experts

My TT and interstate batteries are there years old. The trailer is plugged into my house when not in use. It gets five or so trips per year so is plugged into the house most of the time. It is now on a dedicated 30 amp circuit but was previously on a 15 amp.

We have mild weather, almost always between 35-90 degrees. A few days of subfreezing temps per year, a couple weeks over 90.

I have never added distilled water to the batteries or done any other maintenance. I open the batteries to check there is water in there before every trip... But that's it.

This website sounds like I should be doing a lot more. It also is quite a bit over my head:

Deep cycle battery maintenance

Is the a simpler explanation/resource for the essential tasks and checks I should be doing?

[valhalla360]

wa8yxm wrote:

If you dig enough you will find that on the better battery sites.
I grew up when flooded wet cells were all there were.

Can you provide a link to one of these sites (not your opinion but actual site link)?

Every one I can find says to fill to the bottom of the fill tube but keep the slots on the side of the tube clear.

Of course, the big issue is keeping the plates under water but it's hard to tell how deep they are if you just eyeball it. If you just barely cover them, as you are bouncing down the road, the top of the plates will get exposed and degrade. Using the tubes gives you a built in gauge to determine when to stop.

Honestly, if the rig is in storage and not in use, disconnect the battery once fully charged. You might check on it every 2-3 months but if fully disconnected it should hold a charge. If you use an existing battery switch, make sure it really disconnects everything.

[pianotuna]

rvshrinker,

In your shoes I'd consider an AGM coupled with a modest solar panel system to maintain the batteries at peak levels between trips.

If you wish to know exactly what battery type I'd suggest--feel free to send me a private message.

[rvshrinker]

I’m back.

Went many months without checking and both batteries dried out some. Of course it was right before a trip, Friday night, didn’t want to get stranded boondocking so I went looking for 2 deep cycle marine type batteries, of course everywhere sold out.

So I went back to my batteries with some distilled water, filled them to the bottom of the plastic as best I could but not more, and hoped for the best.

Batteries drained between 1/3-2/3 (according to my TT meter)) which is pretty standard for our summer usage x 4 days (didn’t use the heater, for example).

Now the water is still covering the plates but of course I understand some damage may have been done when they dried out. Plus they are just about five years old. So should I just buy two new batteries? I really, really wouldn’t want to get stranded because most of our camping is off grid. Worst case scenario, I guess I can hook up the trailer to the truck and at least get enough juice to operate the tongue jack and the slide, of course those are my biggest worries because if I can’t get those to operate, I can’t drive home.

I will be more diligent about checking water level and I will buy one of those fillers to be precise.

Thank you

[RJsfishin]

For some reason batteries left on a PD wiz charger 24-365 just do not use any water,....meaning once a year at most, besides that they will last 8 to 10 years, much longer than if not plugged in in between trips.

[MEXICOWANDERER]

LOVE IT
Made a lot of money off that philosophy

[Veebyes]

There is no need to keep a battery on trickle charge 24/7. If the trailer is 12V 'dead', no parasitic drains, the battery will hold charge for months without attention. Just be sure it is put into hibernation fully charged & watered.

Think about it. Farmers & construction companies leave machinery untouched for months at a time in the harshest of conditions. Doubt if they think about the well being of batteries anywhere near as much as the average RVer.

[wnjj]

Our camper has a single group 29 battery and a PD9245 charger. It has been plugged in every minute since 2006 that it wasn't on camp trips. The cheapo Interstate battery lasts at least 6 years before noticing a little loss of performance. I have never once added a drop of water. I quit checking when it was never low.

For our setup/use, "maintenance" is pretty much nothing.

[MEXICOWANDERER]

Jeezo

Try constant voltage after max specific gravity that has been reached of about 600ma per 100 amp hours at 20c

[BFL13]

If you do get to where the water is low but plates still covered and do a really big refill, how long before the SG ever comes out right again? Say you don't do a deep cycle but just a few hours of high voltage--which doesn't do much for the SG, then go on a 13.8v float.

Days, weeks?

Or do you have to do a deep cycle or two?

[StirCrazy]

theoldwizard1 wrote:


For MAXIMUM battery life, I believe that lead acid batteries should NOT be on a charger 24/7 ! 4 - 6 hours per day on a "maintainer" is plenty.

shoot, some one forgot to tell my batteries that. they have been plugged in for the last 14 years and are just starting to show there age this year..

Steve

[2112]

Fill per information provided on #6
Equalize at least once per year per #10
#12 will tell you the general health of your batteries. Check them with a hydrometer a few times a year and equalize if needed
#14 and 15 is good info. Fully charge as soon as possible

Mine is plugged in 24/7 and my junk converter/charger holds a constant 13.6V, which is too high for float charge. I put a timer on my battery that allows it to charge 2 hours every 5 days just to keep it topped off.

[wa8yxm]

CA Traveler wrote:
Add distilled water until it just reaches the bottom of the fill tube. Do not fill to the top of the case/cap. This allows for a adequate reserve and for the battery to vent.

You can buy a battery filler bottle that will fill them to the correct level.

Uh that is overfilling you stop 1/4 to 1/8" BELOW the bottom of the fill tube.. You have to give it "Breathing room".

If you dig enough you will find that on the better battery sites.
I grew up when flooded wet cells were all there were. The first Maintenance free were.. Just Coming out. and that is what they taught back when everybody used them.. Alas they forgot that with the modern maintenance free, which of course are nothing of the sort.

[KD4UPL]

Just keeping the water above the plates is a dangerous gamble. If those plates ever see air it will ruin a battery in a hurry. As has been stated, the water needs to be at the bottom of the fill tube. This allows a bit a reserve. I suspect your batteries need water to achieve this level.

[naturist]

Don’t need a watering system. Those are for helpful for folks with multiple batteries in a hard-to-reach place. Waste of money for us mortals with one easy to reach battery.

Don’t sweat it. If you check the water frequently you are good.