We recently purchased a (New to us) 2008 M-21CKS Mallard by Fleetwood being first time Trailer owners we have hit a few bumps in the road but so far so good. We enjoyed our first outing recently where I selected a full RV hook up site where we could really put her to the test and make sure everything worked... which thankfully it did! But we have a trip coming up where we will be dry camping and I really cant find any information on the Battery disconnect switch and how that works with charging our batteries. The last thing i want is to damage our power converter as we have already has a costly repair due to a leaking skylight-rookie buyers rookie mistake.. super lucky lady with a very handy hubby here :@) The Battery Disconnect switch is orange and located outside near the battery bank and from what I can tell it just has a on/off function1) If connected to shore power ( Camping or at home) should the switch be turned to "ON" ? The first time we took her out I left it off now I am wondering if that was a mistake.. I would assume this would also be the same if connected to generators.2) I would like to charge up my batteries before heading out on our 5 day boondocking adventure.. will the batteries charge if the switch is in the off setting?3) just checked with the hubby and our truck has a 7 prong connection..if the answer to my above questions is yes it should be set to "on" as I understand we can charge those batteries of the truck alternator as we are heading to our destination.

When ever you are using the RV set the switch to on.To fully charge before a trip turn it on seven days before you leave.The seven pin connector does only a tiny bit of charging while driving. Have a wonderful trip!Welcome to the forums.

Congratulations on the trailer and welcome to the forum. As Pianotuna said you basically need to have the switch on for all questions.The switch must be on for the battery to charge from shore powerSee answer above.Yes you can charge via the truck alternator if the switch is on. But really the alternator doesn't give a good charge. I would recommend your scenario 2 above. Plug the trailer in at home and let the battery charge for a few days or more.

The long wire run from the alternator to the RV batteries causes significant voltage drop which results in limited charging while driving. So charge before driving with shore or generator.You can add larger wire and connectors from the alternator to the RV and/or install a DC-DC converter device which will increase the voltage and amps to the RV batteries for a better driving charge.

pianotuna wrote:To fully charge before a trip turn it on seven days before you leave. :(Anything over 1 day and I'd be looking for a new charger. :B

Battery Disconnect switch/charging - ON OR OFF?

time2roll
Nomad
May 13, 2019
If you will be charging with a generator this is a good time to review your charging system. Many converters are fixed voltage trickle chargers and you really want a multi-stage converter that initially charges a low battery at 14.4+ volts.

The batteries need to be maintained between trips. Top issue is to get them fully charged and keep them fully charged for longest life and best performance. If you allow them to run down in storage they will begin to sulfate and may seem charged as you leave but will have lost some capacity.

The 12 Volt Side of Life
2oldman
Explorer II
May 13, 2019
melloftus wrote:
.. we are planning to buy 2 Honda Honda EU2200i Portable inverters to run in parallel if needed as my biggest fear is running out of battery and not having enough juice to get the slide out back in when we are ready to leave.
Those are nice gens and wonderful for running air and such, but you certainly don't need 2 of them to run your slide!
pianotuna
Nomad III
May 13, 2019
Plan on twin Champion generators instead. Or for true convenience one 3400 watt Champion with wireless remote electric start.

Great on the led lights.

I suggest returning the Camco and moving to the Progressive Industries Energy Management unit. https://www.progressiveindustries.net/ems-pt30x The PI unit comes with a lifetime warranty.

Personally I much prefer an autoformer rather than the surge devices. I always measure voltage under load before I plug in my RV as well as checking polarity. I have added surge protection to the autoformer, but it has never been needed. https://hughesautoformers.com/voltage-boosters/

melloftus wrote:
we are planning to buy 2 Honda Honda EU2200i Portable inverters to run in parallel if needed as my biggest fear is running out of battery and not having enough juice to get the slide out back in when we are ready to leave.

I am converting all the interior lights to LED this week so I am hoping this will help with the battery life a bit.

I did buy a Camco 30 AMP Power Defender Voltage Protector With Integrated Surge Protection for when we are connected to power at a campsite and boy am I glad because the site we went to the plug was dang near falling out of the receptacle.From what I can tell this however would not be needed to run on generator power correct?
Thanks again! We will be pros at this in no time!
melloftus
Explorer
May 13, 2019
MitchF150 wrote:
the only time you want to use the battery disconnect is when it's in storage with no power to the TT.

I have to remove my batteries while in storage because they seem to grow legs and walk away, so I take them out of the TT even between trips and the dang thing is parked on the side of my house! I have security cams and lights now, but that was only AFTER the legs grew..

Good luck!

Mitch

I actually have our batteries and propane tanks locked down like Fort Knox as we are no strangers to thievery in our area. The person we bought the trailer from had a metal bar with master locks over the batteries but took it,had I known how expensive it was to replace I would have probably requested it stayed as part of the sale. I was able to find one on amazon called a Batteryshackle for about $130 which I figure is much less than having to replace 2 batteries that learn how to walk overnight.On our first trip the people next were full timers and actually mentioned how we seemed to have everything locked down and was stealing an issue in these parts to which we replied "I dont know but I also dont want to find out." :@)
2oldman
Explorer II
May 13, 2019
melloftus wrote:
I did buy a Camco 30 AMP Power Defender Voltage Protector With Integrated Surge Protection for when we are connected to power at a campsite..this however would not be needed to run on generator power correct?
Correct.
melloftus
Explorer
May 13, 2019
Thank you all for your replies! We are lucky enough to be able to park her next to our house so I will connect her up a few days before the trip but we are planning to buy 2 Honda Honda EU2200i Portable inverters to run in parallel if needed as my biggest fear is running out of battery and not having enough juice to get the slide out back in when we are ready to leave.The lady we bought it from said the batteries were new and according to the sensor in the trailer it says it is fully charged but I am not quite ready to trust it yet. I am converting all the interior lights to LED this week so I am hoping this will help with the battery life a bit.
I did buy a Camco 30 AMP Power Defender Voltage Protector With Integrated Surge Protection for when we are connected to power at a campsite and boy am I glad because the site we went to the plug was dang near falling out of the receptacle.From what I can tell this however would not be needed to run on generator power correct?
Thanks again! We will be pros at this in no time!
time2roll
Nomad
May 12, 2019
Off is off. You want to charge the batteries turn it on. You want to maintain charge while plugged in during storage turn it on.

Only time to turn the switch off would be storage without power or if performing battery service.

Someone needs to come up with a switch that will turn itself on any time the RV is plugged in.
MitchF150
Explorer III
May 12, 2019
the only time you want to use the battery disconnect is when it's in storage with no power to the TT.

I have to remove my batteries while in storage because they seem to grow legs and walk away, so I take them out of the TT even between trips and the dang thing is parked on the side of my house! I have security cams and lights now, but that was only AFTER the legs grew..

Good luck!

Mitch
pianotuna
Nomad III
May 12, 2019
The OP has not said what type of converter is in use. I suspect they don't know.

At 13.2 volts it may take up to 168 hours to fully recharge a battery bank.

This graph is for a single 100 amp-hour jar. Most of us have more. The blue line is 13.2 volts.
midnightsadie
Explorer II
May 12, 2019
X2