Two batteries worth it?

[MadMaxWinny]

I have used the AGMs under a number of demanding situations, from deep discharges (shortest life) to mere starting batteries. They are my battery of choice, until the kinks are worked out of lithium.

[Bobn1957]

If you take the battery to a battery dealer like Interstate they will have a tester that measures the internal resistance of the battery and that is the definitive test for batteries!

[MadMaxWinny]

That only works for starting-load testing, not deep cycle testing. The "20 hour" test is used for that, which is complicated.

[Gunny Rio]

My 2-cents for what it’s worth. Generally speaking we boondock whenever possible and typically will stay out for at least 3 days. We have spent the last 9-years in a Chalet Arrowhead hardside popup that had two 80Ah AGMs on the hitch paired with a 180W solar panel on the roof. Both my wife and I typically bring laptops when we’re out & about (if we have cell coverage we stay out longer and work from the camper). Last August we were rear-ended and the camper uncoupled from my truck and disintegrated.
We started over this past December with a new 1708FB. Nice camper out of the box, however I spent the winter months installing upgrades and making it ‘Ours’. The first upgrade was another 190W roof mounted solar panel, two Battle Born 100Ah Lithium self-heating batteries coupled with a Go Power 3kW inverter installed under the forward dinette bench.
I went all out on this because I didn’t like managing the DoD associated with AGMs or have to worry about cold weather (we camp all year round even in below zero temps). 100 lbs off the tongue is also nice.
So for me, absolutely a second battery is a must. If you plan on keeping your trailer for a while, I would strongly recommend a QUALITY Lithium battery with a full temperature control system and self-heating. I haven’t taken this camper out too much this year, but when I have I never worry about Amp-hours. I only check the Bogart battery monitor because I’m ocd .

[reeman]

As commented earlier in the thread discharging a new 100 AH over night might indicate that something is drawing far too much juice from your single AGM.

For certain check that your fridge is switching properly to propane off grid and not falling back to the battery if it is an auto select model.

Our highest draw overnight is the furnace fan.

We also have an electric/propane hot water heater that seems to use a little bit too much twelve volt power when on propane for some reason or other that I will need to track down. But because the hot water tank is directly under our pillows we shut it off at night so the propane does not constantly switch on and off. I suspect that the propane valve uses a fair amount of power to keep the spring loaded solenoid open during operation. So that might cause a draw issue.

I am also thinking of going old school and changing the water heater to one without the electric propane start and no 120VAC electrical heating element. Sometimes going with the cheaper option is a good thing IMO especially with devices that need to be robust.

Turning off the hot water tank at night and needing to use a BBQ lighter to get hot water like we did with our little 13 foot gem of a Scamp is not an issue for me and adds an old school safety factor to our camper.

Our new twinned 80 AH AGM setup is lasting well completely off the grid. The voltage is stable at full charge voltage for 3 days and goes back up to full voltage if left for a short period of time with no load.

Adding another new AGM in parallel of the same size and AH rating is your the best option IMO.

I have been reading that AGMs will not off gas anywhere near as frequently as sealed deep cycle FLA batteries. Some of newer expensive full fiberglass trailers like the Casitas are locating the battery(s) in slide out enclosures to take the batteries off the front hitch. Which can give a much better distribution to the loading profile of any trailer by reducing the hitch weight.

AGMs were originally created for use in air craft so enclosing them is possible. There is still the distinct possibility of overcharging AGMs and causing the release of gas and overheating like any lead acid battery.

Therefore if installed inside a camper it is imperative that the charging system is working correctly and stops when the battery(s) reaches full charge.

We are considering changing the position of our batteries to take the weight off the short A frame hitch. With this simple modification we can switch to 2 30 lb propane tanks on our Winnie Drop. A very good safety feature would be to also install a full battery monitor system like in an aircraft that includes a temperature sensor for the batteries to prevent a potentially dangerous battery failure due to overcharging.

Going to decent quality AGMs is a step up from the incredibly cheap battery setups that come pre installed by most RV dealers.

Most dealers install thin walled sealed FLA deep cycles that are prone to splitting. Thrown into flimsy containers and are frequently installed so fast that the connections are prone to coming loose as ours did.

The problem with the incredibly cheap setups of todays travel trailers from the big manufactures is that most customers are starry eyed over the interior looks of the trailer. Many rv "consumers" miss the most important factors of buying a shack on wheels that will be off the grid.

Caveat emptor, ces't la vie aujourd’hui.

[BobC]

I wouldn't replace the water heater. When on propane, just turn it off until you really need hot water, it doesn't take long and will stay warm in the tank for quite a while. I don't see how not having 120V is any advantage with respect to 12V power usage.

Our water heater is off 90% of the time when we're not on shore power.

[No1Hunter]

Our water heater is off 90% of the time when we're not on shore power.

Same here. Flip the switch when we walk in the door. Relax a little and then take a shower.

[No1Hunter]

The first upgrade was another 190W roof mounted solar panel, two Battle Born 100Ah Lithium self-heating batteries coupled with a Go Power 3kW inverter installed under the forward dinette bench.

Gunny,

Did you do a write-up on your upgrade? I would be interested to see the steps you took. I have thought about doing the same thing using the battery leads from the forward battery placement to run the "juice" from my solar controller. I'm just not sure if I want to tear into the underbelly.

[reeman]

Originally Posted by BobC

I wouldn't replace the water heater. When on propane, just turn it off until you really need hot water, it doesn't take long and will stay warm in the tank for quite a while. I don't see how not having 120V is any advantage with respect to 12V power usage.

Our water heater is off 90% of the time when we're not on shore power.

Old school water heaters have no electric connection at all and are safer and much more robust IMO. They don't use much propane unless you take 20 minute showers every day or go crazy washing the dishes. The Dometic aluminum in our 2012 Scamp gave us no issues at all and serviced very easily. The newer electric/gas one on our Winnie Drop with a circuit board is really flakey and at present either requires a new circuit board and/or a new electric solenoid gas valve as it faults out on propane and only heats the water up and then goes into a fault condition. Our Winnie Drop is a 2016 the front regulator seems to be ok and the all other functions work fine but the Atwood branded dual function hot water tank is an expensive royal PITA.

It is using a fair amount of 12 volt power when off grid because the brain has to communicate with the sensors and control both the sparking and the electric gas valve. Even though we do turn it off when not in use. It also does not hot hold the water anywhere near as well as the older Dometic did in our Scamp when we turn off the water heater at night or after breakfast.

The Scamp was hands down by far the better designed travel trailer. We missed the opportunity to buy a newer 17 foot Bigfoot by two days for the same money we spent on a Winnie Drop. This is the only reason we were silly enough to buy a newer Winnebago Drop trailer instead just before the pandemic hit and the price of small travel trailers went stupid. Not bad though because with the repairs and upgrades we have done we can actually sell it right now at a profit as we did with our Scamp.

A replacement gas valve and circuit board costs almost as much as switching it out to a gas only water heater with manual controls and no automatic functions. So switching it out to a less expensive option is a more robust and easier to service and use option. Having to hold down a pilot light switch while using a torch to start the heater is no big deal. Also add the bonus of not worrying about getting the electronics wet when servicing the unit.

If this also increases our off grid capacity then Bobs' ur uncle IMO

[Bearpawl]

I personally prefer 2 6 volt golf cart batteries, wired in a series. It will give you approx 350 amps per battery. They are designed for more charges and deeper discharges. I put 2 in my sprinter and they run a 200 watt inverter and my 12 v refrigerator and not had a problem in the last year its been in. if its wired in a series it doubles voltage if in parrelel it doubles the amp hours.
Here is some good info: https://www.atbatt.com/how-to-wire-6...configuration/

https://thecampingnerd.com/how-to-wi...-batteries-rv/

[No1Hunter]

It is using a fair amount of 12 volt power when off grid because the brain has to communicate with the sensors and control both the sparking and the electric gas valve.

And just how much power does that microprocessor draw when the Hot Water tank switch is in the "On" position? Have you actually tested it, considering you state it uses a significant amount of 12v power?

How much gas does that pilot light use being on all the time? Our fireplace guy told us to leave them off on our home gas fireplaces as they will use a lot of gas, more than the few times you use the fireplace. LOL

[creativepart]

Originally Posted by Bearpawl

I personally prefer 2 6 volt golf cart batteries, wired in a series. It will give you approx 350 amps per battery.

6v GC batteries run about 220 amp hours each and when wired in series to give you 12v they produce a total of 220 amp hours - Not "350 per battery."

Of course, if you can point us to 6v GC batteries that have 350ah capacity please do us a favor and provide us a link to these.

Also, they aren't really forgiving of "deeper discharges" either. 6v GC batteries are actually more harmed by deeper discharges than 12v AGMs, etc.

[No1Hunter]

Of course, if you can point us to 6v GC batteries that have 350ah capacity please do us a favor and provide us a link to these.

I was wondering the same thing. I know the Trojan T-145 batteries are not that high, and they are a highly rated 6v battery.

[reeman]

Originally Posted by No1Hunter

And just how much power does that microprocessor draw when the Hot Water tank switch is in the "On" position? Have you actually tested it, considering you state it uses a significant amount of 12v power?

How much gas does that pilot light use being on all the time? Our fireplace guy told us to leave them off on our home gas fireplaces as they will use a lot of gas, more than the few times you use the fireplace. LOL

It is not so much the microprocessor that would be using excess current on our Atwood heater, but it could be the electric gas valve causing the microprocessor to cycle the propane valve on and off erratically as the heater comes up to temp on the gas only function. On AC 120v power only the unit works fine but something causes the same fault on the gas side when operated in dual mode.

Either way it is a weird behavior that requires more electrical power than it should when operating on propane only. The electric gas valve uses current and seems to create a draw that it shouldn't.

You have piqued my interest. I will measure it with a VOM during the 4 minute failure cycle when it fires up the flame multiple times before indicating that there is a fault condition present and shutting the system completely down.

The little light beside the hot water switch does go on after the brain decides that there is a fault as designed, the unit will not restart until I reset the unit by turning the switch off to reset the microprocessor as instructed in the manual.

Therefore the problem is either a faulty gas valve or a faulty microprocessor unit, the gas flame is perfectly adjusted and the pair of thermostats and the thermocouple/sparker are brand new and properly installed.

If there is a model of hot water heater that uses both electric and gas without relying upon a crappy failure prone circuit system with electric spark and electric gas valve then I would buy one. Because the newer Dometic/Atwood high end logic chip controlled one is a royal PITA and obviously needs more expensive work and diagnostics than some automobiles.

Reminds me of when VW brought out the first rabbits with electronic ignition and failed to shield the wires from EMR. Causing the first rabbits to became known for having the engine crap out when in the presence of strong radio signals.

Even though the previous owner of this trailer took it several time to the local Winnebago dealer and had it "serviced", apparently this particular expensive hot water tank has never worked correctly from day one even when serviced by so called "experts" at a Winnebago dealership. We bought it knowing this and just put up with it.

Worse still the so called dealer "service" of the trailer consisted of winterizing it for the customer and squirting too much grease into the stock upgrade deluxe bearing buddies on the Lippert axle.

I was lucky enough to catch that grease monkey fault in time and change out the bearings and the drums, fortunately all that happened by the 2 year break and bearing service not being correctly done by the dealer was a little grease got past the spindle grease seals on the drums and none got to the brakes.

So if anyone thinks that the RV dealers south of the border are cheap cut corner operations with unqualified staff then just come up to BC with your travel trailer and try to get good service! I am not saying that Winnebago and their dealers are any better or worse than the other big manufactures of RVs.

Just that anything you can do to improve the trailer and install better products than what comes as stock is a good idea, especially when it comes to the running gear and the other essentials like electrical systems and components that are low spec right from the manufacturer.

Fortunately the frame and bonded fiberglass skin seems high quality so it is worth fixing the crappy stuff that came stock. Even if this means changing the axle, the battery setup, the water heater, and the propane tank holding and battery mounting setup on the hitch frame.

At least this Winnie has decent windows and doors correctly installed. Unlike some of the poor suckers who bought RPODS after Forest River started to low spec that unit and bang 'em out of the assembly lines to increase the profit margins per unit because lighter small trailers started selling like hot cakes around 2015 to us baby boomers with lower incomes.

Well enough ranting, I have a trailer to work on again if we want to use it next week as planned.

Happy Camping and all the best down south I enjoy fishing with you on our ponds here in BC!

[creativepart]

Reeman, I don't think the water heater uses more than a tiny bit of DC to operate on Propane. I'd be surprised if that is your issue. You should have it checked out by a good RV Tech. They see TONS of water heater repairs and should be able to isolate your problem with surging on Propane.

But, even with the surging I really doubt that's the power hog you're seeing.