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Figuring this power stuff has my head spinning

SoonerWing03
Explorer
Explorer
***disclaimer*** reading most of these power related threads is like reading something where 50% of it is in a language I don’t speak/read/understand.

I am planning a 10 - 12 day family summer vacation to the Yellowstone Grand Teton area and it looks like we might need to do a fair amount of boondocking.... which is fine by me but we have yet to do. We will do some practice runs around home first but my question is more about which or what size power converter I should upgrade to.

My rig currently has the WFCO WF-8955PEC which I understand is not a great converter. I just removed a single Marine style 12V battery in favor of two 6V G2 Golf Cart batteries. My understanding is that is an upgrade but a good example of how good of a grasp on this is that I was shocked when I got to Sams to purchase said 6V batteries and to my surprise they were roughly the same size as the 12V :h I was expecting them to be roughly half the size because well 6 is half of 12.... so that is what you are dealing with here.

I am looking to pick up an inverter for the camper (2017 MPG 2400BH) trip and wondering if a 3500 watt (like a Predator or Champion) watt would be sufficient or could I even get by with a 2000? Additionally, what converter should I consider?
35 REPLIES 35

Vintage465
Nomad
Nomad
SoonerWing03 wrote:
valhalla360 wrote:
Big question: What do you plan to run when off the grid and how long?

Odds are the charging unit (converter) isn't a big issue worth addressing right now.

Do you plan to run air/con off grid? If yes, that means the generator will be running and charging isn't a major consideration. This is typically the turning point between operating off battery power vs running the generator.

If you are just running a few lights and maybe the TV off battery, you batteries should get you at least a couple days and then an hour or two running the generator (which powers the battery charger) should keep you going.


For this trip I doubt we will need the AC but if I am going to purchase a generator I might as well get one big enough to run the AC in the event that we want to go off the grid in lower elevations. Going off grid just opens up sooooo many more opportunities and is really at the essence of what I want our family camping experiences to be. However my wife is more of a "glamper" so I will have to meet her in the middle.

We like our coffee in the morning and the kids will want to be able to charge their phones at night. We would probably watch 1 maybe 2 tv's for an hour or two in the evening and may play a movie on 1 of them requiring a DVD player. If the phones have much of a signal at al, they will opt for playing around on them rather than the TV once the sun goes down. 1 or 2 lights max would be all we need and they are already LED's.

"We Like our coffee in the morning..." It is really easy to make great coffee on the stove top with a percolator or use a quality drip type unit you pour water through. If you can....the less items you run off 110v, the easier it is to keep the 12volters up.
V-465
2013 GMC 2500HD Duramax Denali. 2015 CreekSide 20fq w/450 watts solar and 465 amp/hour of batteries. Retired and living the dream!

mordecai81
Explorer
Explorer
I have a Champion 3000w generator that will run the AC and a stand alone 60 amp Boondocker charger that I plug into the generator and then use jumper cables to attach to the battery posts. It charges the battery as efficiently as is possible via a generator. We also have roof and portable solar that is either very helpful or not at all depending on weather and shade. If you charge only with the built in converter/charger, NPS campgrounds don't have long enough generator hours to get the batts fully charged.

PNW_Steve
Explorer
Explorer
In my 5er I have two GC-2 batteries in series. It has been a good and necessary upgrade for us.

We have a Honda 3000 watt inverter generator. We have a single roof air and can run it and everything else in the trailer with no problem.

I have heard a lot of good things about the Champion generators but I have to plug the Honda's reliability and longevity. I have had mine for 12 years and I cannot even guess how many hours it has on it.

We lived off grid for a while and ran it 12-16 hours a day. Then we got utility power and became dependant. So, when the power went out we ran the generator hard 24/7. Our power outages were frequent in the Winter and lasted as long as 11 days.

I am amazed at how reliable it has been. Oil, air filter and spark plug changes and one carb rebuild. It's still running strong.
2004.5 Dodge 3500 5.9 Cummins, NV5400, 5" turbo back stainless exhaust, Edger programmer & 22.5 Alcoa's
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1992 Jayco 29 5th Wheel (Mexico veteran & headed back)
2002 "faux" Wanderlodge 40' My new toy....

SoonerWing03
Explorer
Explorer
I want to thank you all for your comments. It will take me several readings and additional research for me to process what you are telling me but I am extremely grateful that you all have taken the time out of your day to even respond and help me. I can’t thank you all enough for being such a valuable and positive resource for people like myself trying to make sense of all of this.

Boon_Docker
Explorer III
Explorer III
Group 31 is a little over 2.5 inches longer than a GC2. So if size matters the GR31 could be a problem for the same amp hours.

SoundGuy
Explorer
Explorer
SoonerWing03 wrote:
I just removed a single Marine style 12V battery in favor of two 6V G2 Golf Cart batteries. My understanding is that is an upgrade but a good example of how good of a grasp on this is that I was shocked when I got to Sams to purchase said 6V batteries and to my surprise they were roughly the same size as the 12V :h


A 6 volt GC-2 battery has a similar footprint to a 12 volt Group 24 battery but is about an inch taller. A 12 volt Group 27 will be about the same height and width as a Group 24 but is longer. Same for a Group 31, just even longer than a Group 27. What is best for your application depends on how you intend to use your batteries and the physical space you have for mounting them. As for the "anti 12 volters" don't let them kid you - a pair of Group 31 12 volt batts wired in parallel will offer about the same reserve capacity as a pair of 6 volt GC-2 batts wired in series. Oft times one is better off with a pair of 12 volters rather than the usually recommended 6 volters because the former will offer significantly lower internal resistance and thus suffer less voltage drop under heavy load from an inverter trying to meet that load. The same can generally be said for AGM vs flooded, the former having much lower internal resistance and therefore more likely to power a large inverter under heavy load with less voltage drop and thus less likely for the inverter to alarm or even shut down from excessive voltage drop.
2012 Silverado 1500 Crew Cab
2014 Coachmen Freedom Express 192RBS
2003 Fleetwood Yuma * 2008 K-Z Spree 240BH-LX
2007 TrailCruiser C21RBH * 2000 Fleetwood Santa Fe
1998 Jayco 10UD * 1969 Coleman CT380

wa8yxm
Explorer III
Explorer III
I will deal with the size issue.

Many posts the person says "I have a 12 volt battery".. great. I'm looking at a 12 volt battery as I type. I can hold it in one hand comfortably 7 Amp hours capacity.

I once borrowed a battery from a battery company for a weekend This sucker was a good 4 feet long. 3 or more high and a foot thick. they loaded it on my rented trailer with a fork lift. another of the same powered the fork lift.. About a thousand amp hours.

See what "I have a 12 volt battery" is not enough information.. both are 12 volt batteries

Tw2 GC-2 batteries roughly equal one 4D. that's 220 Amp hours at 112 volt

YOur Group 24 was likely about 70-75

It is the number of WATT-HOURS (Amps times volts times hours) that determines the volume (And weight) of the battery... For most 12 volt lead acid batteries. from Flooded wet to AGM. the size and weight needed to hit 200 Amp HOurs capacity are nearly identical.

Now the WFCO converter
Nothing wrong with it till it fails. then get a Progressive Dynamics upgrade.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
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NRALIFR
Explorer
Explorer
You’re right, you most likely won’t need the AC in Yellowstone/Grand Teton, but if you anticipate needing to use generator power for AC later, I would give serious thought to buying two smaller parallel-able units rather than one larger.

I actually have a 3600 watt Generac LP unit built in to my TC, but I’ve found that the 1000 watt Yamaha is what I use 99% of the time. The generac only has about 125 hours on it and it’s 18 years old. Most 3KW or bigger units I’m familiar with are quite heavy.

:):)
2001 Lance 1121 on a 2016 F450 ‘Scuse me while I whinge.
And for all you Scooby-Doo and Yosemite Sam types………..Let’s Go Brandon!!!

MEXICOWANDERER
Explorer
Explorer
I grew up 70 miles NW of Yellowstone. In SUMMER I remember arising for breakfast at 0500 then heading off for chores at 0630 I was wearing a lined leather jacket.

Seeing my breath. Water from the hand pump was so cold I curled my lip under so the temperature shock would not take it out on my front teeth.

You might want to think about the furnace fan draw unless your family is cold weather folk. I don't remember too many times where I ended up not having to tie my leather jacket onto the saddle around ten AM. Obviously I did not carry a thermometer around 🙂

ajriding
Explorer II
Explorer II
6 volt batteries are just half the voltage, not half the size. Size has nothing to do with voltage. Those little AA batteries for flashlight are small, but the same size could be an 18 volt batery.

Benefit of two 6 volt is that they run in what is called "series" not "parallel" meaning they one battery's current flows into the other battery and this doubles the voltage. Is like when you stack two D cell batteries in your flashlight and this makes 3 volts.
Parallel means that the two batteries are both feeding into your camper but are not connected other than at where they are connected to the camper.
When two 12 volt batteries share a connection then if one has a better charge (higher voltage) then the weaker battery will pull voltage from the stronger one to try to charge itself, or said in another way, the voltage will try to equalize between them, but all that happens is that the weak battery drains the strong battery. If the weak battery is 11 volts and the strong is 12 volts then at that moment you will see 11.5 volts, but the 11 volt battery will eventually deplete the strong battery down to 11 volts also so both will be 11 before long. 11 is considered a dead battery.

The 6 volt in series will double the voltage (add voltage of one to voltage of the other, 6+6=12). There is no parasite battery and one does not drain the other. You could have a 6 volt batt and a 5 volt batt to add up to 11 volts and you will have 11 until you drain the battery with your lights running, or TV or fan. But the 5 volt batt will never drain off the stronger 6 volt batt.

Good that you took this advice without even knowing why I guess.

You will not need a converter for boondocking. Likely your converter is fine. Dont mess with it. All it does it turn the Household current into battery-type current, DC current so that the DC power things in your camper (lights, water pump etc) will run off the household current rather than run down the battery. The converter almost always has a battery charging function built in.

You will need an inverter. Inverter takes DC battery power and makes it into AC household power. Most inverters are what is called modified sin wave. Sine is math and spelled sin, not like Adam and Eve sin, but sin as in sine wave.
A modified sin wave is square instead of nice and curved like ocean waves. Some devices will be harmed by a modified sin wave, but most things not. Things that use a power adapter like your phone charger, laptop plug will be fine. Try to power your items from the DC outlet instead of the inverter if you can.

1,000 watt inverter will be enough. This will be called 2,000/1,000 meaning it runs at 1,000 watts, but can peak out at 2,000 for a second of two. If you need to run power tools then you will need more wattage, but for TV this is fine.

Be aware that inverters use a lot of power. Running two TVs and charing all the kids **** will run batteries dead. You will not have remaining power for the heater, or fans, or lights or the water pump to flush.

Have the kids turn off phone apps that eat up battery on their phone. Kids are not savvy with electronics, that is a myth. Have them turn off the bluetooth, turn off the wifi and turn off cell if there is no signal. Those eat up battery and then they need to recharge off the camper more thus running down what little battery you have.

If you must have a boob tube then get on that runs off DC power, not AC which requires a wasteful inverter to turn DC into AC to run the TV which actually turns the AC back into DC anyway inside its workings.

Keep a battery lantern as you will probably have dead batteries at night.
Recharging off a generator will take a long time and you will need a stronger charger than is built into you camper converter. Dead batteries can take hours to recharge depending on how strong the charger is.

Having at least 200 watts of solar on the roof will help tremendously. With solar you should charge things early in the day when the batteries still have time to recharge before it gets dark.

With solar you actually are still running off the batteries. The solar charges the batteries and your power comes off the batteries. Electrically the power is all the same, whether battery or solar, but the solar is not providing enough current to run your big needs so the battery is supplying the current.
Think of filling a water bucket with two hoses. A big hose and a little straw size hose. Both are putting water in, but when you use a lot of water it is the big hose that is really contributing to your needs. The little hose represents your solar, and the big hose represents you battery charger that is powered by the generator or household current.
While driving your car alternator can also charge the battery, but it is also quite a small hose.

TenOC
Nomad
Nomad
1. It will not help you with TV but most RVs have a 12 Volt outlet near the TV. I purchase a 12 volt multi-port USB adapter that will allow you to charge your phones from the house batteries.

2. Teach the kids to play board games or card games -- not to play with electronics. Plus you have family face time.

3. While not the best solution, you can always charge the house batteries by running your truck for a few hours. Depending on how often you camp, fuel may be cheaper than a generator.
Please give me enough troubles, uncertainty, problems, obstacles and STRESS so that I do not become arrogant, proud, and smug in my own abilities, and enough blessings and good times that I realize that someone else is in charge of my life.

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ppine
Explorer II
Explorer II
YOur expectations may not be realistic.
I would put the money in a generator and/or solar set up.
You will need 3000 watts to run AC, but will not need it where you are going.

time2roll
Nomad
Nomad
SoonerWing03 wrote:
I am looking to pick up an inverter for the camper (2017 MPG 2400BH) trip and wondering if a 3500 watt (like a Predator or Champion) watt would be sufficient or could I even get by with a 2000? Additionally, what converter should I consider?
Do you expect to use the air conditioning? Best to go 3000/3500. Some get by with 2200 and a microair electronic start capacitor. For microwave and anything else (one at a time) the 2000/2200 is fine.

For just recharging batteries 2000 is fine. If you get a smaller 35 amp converter you could even charge fine with a 1000.

For replacement converter the most direct swap would probably be the PD4655L MBA Wildcat

http://www.bestconverter.com/PD-4655L-MBA-WildKat-55-Amp-Main-Board-Assembly-for-WFCO-8955

SoonerWing03
Explorer
Explorer
valhalla360 wrote:
Big question: What do you plan to run when off the grid and how long?

Odds are the charging unit (converter) isn't a big issue worth addressing right now.

Do you plan to run air/con off grid? If yes, that means the generator will be running and charging isn't a major consideration. This is typically the turning point between operating off battery power vs running the generator.

If you are just running a few lights and maybe the TV off battery, you batteries should get you at least a couple days and then an hour or two running the generator (which powers the battery charger) should keep you going.


For this trip I doubt we will need the AC but if I am going to purchase a generator I might as well get one big enough to run the AC in the event that we want to go off the grid in lower elevations. Going off grid just opens up sooooo many more opportunities and is really at the essence of what I want our family camping experiences to be. However my wife is more of a "glamper" so I will have to meet her in the middle.

We like our coffee in the morning and the kids will want to be able to charge their phones at night. We would probably watch 1 maybe 2 tv's for an hour or two in the evening and may play a movie on 1 of them requiring a DVD player. If the phones have much of a signal at al, they will opt for playing around on them rather than the TV once the sun goes down. 1 or 2 lights max would be all we need and they are already LED's.

philh
Explorer II
Explorer II
I replaced my wfco converter. HUGE difference with Progressive Dynamics MBA wildkat unit