Do the batteries recharge while towing?

[jwalt313]

We are newly retired and are now the owners of a 21 foot travel trailer (FR 21FBRS) and we love it! We are very experienced with boondocking, water conservation and limited electricity after many, many years of camping in a tent and pop-up, but we have never had a gas refrigerator or gas heater before.
We are planning a Fall New England trip, staying mostly in State Parks with no electric hookups. I understand that the gas refrigerator and gas heater will still draw electricity from the batteries. I am guessing that we will probably have to run the gas heater at that time of year. How many days would you think we could get from 2- 6 volt batteries while we conserve as much electricity use as possible? We are thinking of staying 3-4 days at each campground. Will the batteries recharge during the 2-4 hour tow to the next campground? We are hoping to not have to buy a generator. Any advice would be appreciated.

[2rad4u]

With conservative furnace use, you can get 3-4 days out of the 6 volt batteries.

That is the same setup I have.

I use a Mr Buddy Heater if it's really cold and we need more heat. I crack two windows and have not had a problem as it's rated for indoor use.

I keep the hot water heater off and only use the water pump as need (I don't leave it "on").

LED lights help but I still keep the light use to a minimum. A battery powered lantern comes in handy if you really need to conserve power.

I few hours behind the truck WILL NOT RECHARGE the batteries. It will help, but will not give them a full charge.

I recommend a gen if your moving from one boondocking site to another so you can maintain the batteries properly. I'm looking at one as well.

[bikendan]

Most tow vehicles only provide a trickle charge at best.
Your furnace will be the biggest power drain. Fridge and water heater will not use much.
We are also experienced dry campers but we wouldn't be without our trusty Honda 2000i.
2-4 hours of towing will NOT fully charge depleted batteries.
I think you're going to need a generator or solar panels.

[2ondago]

We added two 100 watt solar panels to help recharge the batteries while on the road as well as parked. We can get about 15 amps on a good day plus the trickle from the trucks alternator. Using two 6volt golf cart batteries and a solar controller. We keep the converter off most of the time to keep from cooking the batteries.

[BarabooBob]

I added an extra 6 gauge wire from the power distribution box under the hood of the truck to the battery. I hope that I get a better charge due to the heavier wire. I will be checking the charge rate when I borrow my friends amp meter this weekend.

[nayther]

Understand that when you plug in your tow vehicle it puts all the batteries in parallel. If the trailer batteries are low, they will draw down the TV battery and all will equalize. The alternator senses SYSTEM voltage so it will not sense a real low battery and hit the system with its full amps. The initial "hit" will bring them up some but it takes a LONG time to get them to peak charge as the alternator drops off. This is also the case with a standard converter when you plug in to shore power or run a generator; initially the amps are high and the voltage jumps up pretty fast but as you approach "full" the converter will back off. With the better after market converters they will stay at high discharge longer. I was amazed at how much better my last trailer charged after I switched to a PD 60 amp converter from the stock POS 40 amp. So yes, you'll need some help.

[clintbonnie73]

Suggest buying this voltage meter below ($12) and plug it into your 12 volt outlet in your trailer.. With the vehicle engine off, the meter will read your battery voltage (around 12.3 volts).. Then start your engine, check the voltage and it should read around 14 volts if charging properly..


https://www.ebay.com/itm/Prime-Produ...oAAOSwdHpbykIF

(Amazon sell the same meter but $40)

[rracer5]

X2, 3 & 4 on the TV not fully recharging your TT batteries. Also, if you haven't already checked, you should check to see if the 7-way receptacle at the rear of the TV has a live 12v power from the alternator. Depending on the manufacturer, some ship the vehicle with fuse/relay for that circuit already in place and some are supposed to be installed by the dealer as part of the "towing package" prep. (if it came equipped) before you take delivery. On my old Chevy (2002) even though it had a so called trailer package, I had to install my own 40 amp. fuse in the power distribution box under the hood in order to feed the constant 12v power to the 7-way trailer receptacle.

If you want some peace of mind just in case, you might consider either of the 2 economical (& quiet) inverter gensets below.


https://www.harborfreight.com/900-ma...arb-63025.html

https://www.harborfreight.com/2000-w...tor-62523.html

[DanMistyMiler]

I have a 2017 21FBRS and have found the following by applying an amp meter to the trailer to get an idea on what the draw is for the different systems. Here is what I recorded. Keep in mind that each item includes the parasitic draw.

Base parasitic draw - 0.17 ah
Refer (on gas) - 0.58 ah
Furnace - 2.6 ah
Hood Fan - 1.23 ah
Hood light - 1.38 ah
Bath Fan (on high) - 2.67 ah
Ceiling light (1) - 0.45 ah
Ceiling lights (all) - 2.54 ah
Lights on JN Sofa (1) - 0.27 ah
Scare Lights - 1.14 ah
Porch Light - 1.52 ah
Hot Water Heater (on gas) - 0.78 ah.


For what it is worth to you.

[transmission_doctor]

Suggest you check your tow vehicle fuses, my 04 Silverado is fully wired for towing, however the fuse for the battery circuit that feeds the trailer connector was missing.

Also be careful when you are boon docking to unplug the trailer from the tow vehicle, I spent the night at a Loews and left the trailer plugged into the tow vehicle, had to get a jump to get it started the next day. My cpap discharged 3 batteries to the point the tow vehicle would not crank.

[RitaB]

Someone mentions solar to recharge your batteries. Just remember most NE state and federal parks are well wooded. Solar would work if you have good sun for most of the day. Last year I ended up on a site that only gave me sun as it passed overhear (just a couple hours) the first day. When I went to bed they forecasted rain in the evening the next day. When I got up it was cloudy, No sun. With no sun, I knew I would last no more than 2 days. Packed up and had to find a place with power for overnight.

[Herk7769]

Bring a small Harbor Freight generator and a dedicated battery charger.
Plug the charger into the 120 volt outlet on the generator and charge your batteries that way.

Lots more efficient than using the truck or the solar panels. The truck's alternator is good for keeping a charged battery topped off, but horrible at recharging a deep discharge battery. I attached a PDF on why that is if you are interested.

https://www.harborfreight.com/900-ma...arb-63024.html

https://www.harborfreight.com/2815-a...ger-63299.html

[FishinGuy]

I love these electrical questions.
Two sides to each equation, electrical power used vs electrical power put back into battery.
Regarding the TV, please consider the size of the wire guage leading back to the hitch point. Now consider the wire guage from the alternator to the battery. Small wires equal voltage drop, so the charging output goes to the path of least resistance. And the start battery does not get drawn down much. So very quickly the alternator voltage ramps down.
Now into the TT, same thinking about wire size. The main DC wire in my TT is a # 6 wire for battery to panel. On the uses side, how many uses are drawing even close to 10 amps ? Few ! Now to the charging from the converter to the battery. How long is that # 6 wire ? In my 261xlbh it was nearly 30'. How much voltage loss trying to push 30, 40, or 50 amps back into the battery ? It is like trying to run the fire hose flow thru a garden hose. Get a generator, a good portable charger, and hook it directly to the battery posts. Or do some re-wiring.
Hope this helps

[Theo]

RitaB makes a key observation: lots of shade at state parks here in New England! If you want to try a solar solution, make sure the panels are moveable and attached by a fairly long cable.

Choose your campsite carefully! You can use Google Map's satellite view to help determine the amount of shade at a campground/site. Also, I have found that the state parks' descriptions of the sun/shade at their campsites is pretty good, but sometimes not. If depending on solar, call ahead for info about the site.

BTW, Vermont has very nice state park listings! They post interactive maps on their park websites that allow you to see a photo of the campsite by clicking on the campsite number. I have found that there are a few very sunny campsites in VT at state parks near the east banks of Lake Champlain.

Honestly, a small, quiet genny in New England will give you much more freedom to camp. I might also mention that state parks are usually booked solid during leaf-peeping season. Independent campgrounds also fill up quickly for reservations during the first week or so in Oct., and their campsite rates go up as well.

Finally, if you are traveling in New England for the leaves, start in the northern areas first (Maine and upper VT/NH, then work your way south toward MA. Depending on the length of time spend at each stop, you'll be following the southern advancement of "peak" season.

Theo

[clintbonnie73]

I agree.. when using solar panels, make them portable. mine works good when around trees.. I just move a few times a day.. Here is my solar panel set up..

https://www.amazon.com/dp/B00JML23X0...v_ov_lig_dp_it

[jwalt313]

Thanks everyone. You have been so helpful. We are now considering getting a generator as we prefer state park and national park camping, preferably in heavy shade. Now, we need a lesson in using a generator. We currently are using a Battery Tender to charge our battery at home. Do we just attach the Battery Tender to the battery and then plug the Battery Tender into the generator? Or do we plug the TT directly into the generator without the Battery Tender? We are also considering the Honda 2000i. Any opinions?

[bikendan]

Plug the shore cord directly into the generator. You don't need a battery render when your RV has a converter, which is way more powerful than a battery tender.
Honda and Yamaha are the Gold standard but there are many good less-expensive options.
If you don't plan on using the a/c, a 2000w inverter generator will be perfect.
We're experienced dry campers and don't go anywhere without our Honda 2000i.

[Herk7769]

In my opinion, a dedicated 4 stage charger is way more efficient at recovering deep discharge batteries than the converter. The converter's first priority is camper DC power and what is left goes to charging the battery. It is also only a 3 stage charger.

I would not consider a new old stock Honda 2000i (unless it is a good used unit). The new replacement Honda 2200i (same price as Honda 2000i) and outputs 2000 watts continuously and peaks at 2200 watts. The old Honda 2000i only outputs 1700 Watts continuous.

I would also buy the Honda 2200i Companion model FIRST as it is already configured with everything you need to parallel with a Honda 2200i or Honda 2000i (certain serial numbers) right out of the box.

[babock]

Originally Posted by Herk7769

In my opinion, a dedicated 4 stage charger is way more efficient at recovering deep discharge batteries than the converter. The converter's first priority is camper DC power and what is left goes to charging the battery. It is also only a 3 stage charger.

Of course unless you have a Progressive Dynamics converter with the Charge Wizard which is a 4 stage charger.

[FishinGuy]

Herk is giving good advice about the difference between chargers and converters. #6 wire at 30' one way is good for about 25 amps, but ampacity tables want you to figure roundtrip now your only good for about 15 amps because of the voltage loss. Converters have a problem unless you shorten the run length, or rewire . People installing a inverter/ charger typically put it within 10' max from the batteries. The factory installing converters are not concerned about battery charging, there supplying DC to the trailer as a 1st priority as Kerk has indicated.