Let's Talk Power Planning

Bbasso

Expedition Leader
At this point with everything I'm seeing about your electrical needs I would probably lean toward a sizable house battery Bank and a very large inverter usually double or two and a half times your highest rated device and then the blue Seas 7622 to feed all the batteries. I don't think you can manage an air conditioner without harming your batteries unless as mentioned earlier you consider them disposable. Honestly I wouldn't even try. Everything else can be run off the big battery Bank, inverter and blue sea 7622 just be sure to have your vehicle running for those heavy loads.
 

Ozarker

Pontoon Admiral
Well if you gotta have the microwave, which means a big inverter, the coffee machine becomes a non-issue (except maybe running its hot plate for hours).

You won't run the a/c off the battery bank. So you need a genny big enough to run the a/c or the air compressor (whichever is the heaviest load).

And preferably, the a/c and the battery charger (what the hell, the genny is running anyway, might as well).




Depends on what you mean by large battery bank. Four Trojan T105 6v GC batteries rigged series/parallel for 12v can get you a 450ah bank.

To make the math easy let's assume 600w for the a/c with compressor running.

450ah x 12v = 5400 watt*hours
5400wh ÷ 600w = 9 hours.

So if you are prepared to sacrifice the batteries, you could get 8 hours of a/c run time (more if the compressor doesn't run constantly) before the bank was dead.

With T105s you can do that around 500 times before they are shot.

Now figure the 1400w Champ. Battery charging at 14v would be 100a to the battery. But that's a bit much load for a 1400w genny. So say a 55a Iota.

55a x 14.5v = 800w

Enough to run the a/c and still have 200w (÷ 14.5v = 14a) going into the battery bank.

So run the gen during the day to recharge and power the a/c. Run the a/ off batteries at night.

IF you treat your house batteries as disposable and IF the a/c is small. If you want long battery life, then you would need to double the bank to 8 batteries.

And of course that's running the a/c off the inverter (couldn't run the a/c and 55a battery charger both from a 1400w gen, so you run the charger off the gen and run the a/c off the charger).


And the battery/inverter will be big enough to run the micro or air compressor for a good long while without firing up the gen.


If you go with the small battery, large gen scenario, you'll be running that gen all the time.



And forget the HF solar, get something decent. You want more watts per square foot of limited space.

Very good points, thank you!

The air compressor is a seldom used item and turning off the AC while using it wouldn't be a big deal, but it's just good to have.

Looks like the AC is gen set only, the micro and anything else can go off battery and inverter when the genny is off.

I'm seriously considering 2 6V GC batteries, plus my trolling motor battery, not sure if I would hook them together (parallel the 6 and series with the 12) or keep them separate. Then I'd still have a dedicated starting battery separate from all the other stuff.

:coffeedrink:
 

comptiger5000

Adventurer
Personally, I'd plan to run everything except the A/C off the batteries with an inverter. High draw items like the coffee pot will be fine, as they're only for a few minutes at a time.

A/C can either be run with engine running if the inverter is big enough or if you'll be using it a lot, get a small generator for it (and a battery charger so the generator can top off the batteries while it's running).
 

Ozarker

Pontoon Admiral
At this point with everything I'm seeing about your electrical needs I would probably lean toward a sizable house battery Bank and a very large inverter usually double or two and a half times your highest rated device and then the blue Seas 7622 to feed all the batteries. I don't think you can manage an air conditioner without harming your batteries unless as mentioned earlier you consider them disposable. Honestly I wouldn't even try. Everything else can be run off the big battery Bank, inverter and blue sea 7622 just be sure to have your vehicle running for those heavy loads.

Thanks for the clarification, that really works!

As I just mentioned, looks like larger battery bank and sufficient genny is the way to go.

If I double the AC requirement for the AC, that gives us extra juice to charge the bank while the AC is on or to run whatever, like the compressor since the real draw from the AC is at start up. That or for a few seconds of microwaving with the AC.

That leaves the inverter, 1 1/2 or 2 times the load of the micro should do it.

No, my batteries aren't dispoible, they cost too much and I'm cheap, if I were full timing I wouldn't be so cheap but for one or two week trips.

I'll look up the blue sea, I'm not used that before, I might have had that on my boat but I never fooled with it or the batteries.

Thanks again for the feedback :)
 

dwh

Tail-End Charlie
I'm seriously considering 2 6V GC batteries, plus my trolling motor battery, not sure if I would hook them together (parallel the 6 and series with the 12) or keep them separate. Then I'd still have a dedicated starting battery separate from all the other stuff.

:coffeedrink:

No can do.

When batteries are tied into a full-time bank, they must be as identical as humanly possible. Same brand, type, size, age - hell even the same production batch if possible.

In a full-time bank they all live, wear out and die together as one big battery. If one is different, it will do more work and wear out sooner. This will then cause the rest to end up doing more work.

End result - premature failure of the whole bank.

(This does not apply to batteries only tied during charging - that's no problem.)

You could keep the trolling battery separate and split loads. Like 12v lighting on that, and the 120v inverter stuff off the big bank.
 

vartz04

Adventurer
if you only want to spend $1000, plan on only running the AC, Coffee Pot, and microwave when on shore power. You don't have enough to buy a good quiet generator and do the 12v set up. My suggestion

Trolling Motor Battery (you say you have 1, so that will work for now) - $0 since you have it
Battery Tender charger. $80 - Will need to add in a power inlet plug if you want it mounted on board. that is another $15, figure some wiring/connectors for this and just call it $100.
Solar Charge Controller and Solar Panel - Cheap version $150 from Harbor Freight. Decent stuff $300 from Amazon. Both will get you 100-200 Watts of charging.
Misc Wires/Connectors, ports fuses ect for 12v Power - $75.
1500 Watt Inverter - $400+ for pure sine wave, $100 for Mod Sine Wave.

Thats $425 for the cheap stuff to just get the power system set up, $875 for decent stuff.

Suggestions on what you plan to run.
Fridge - Will run fine off the battery set up above.

AC- is what it is but you are going to need shore power or a generator if you want to use it. The generac IX2000 i had worked well but was much louder than the honda and will run the 6000 BTU window shaker that I have at home. The generacs are only like $500 so if you get the cheap stuff and the generac generator you are still under $1000 but will likely need to upgrade/replace down the line.

Microwave - Forget it. There are other ways to heat food. Grill, Camp Stove, ect.

Air compressor - what is this being used for? just filling tires? get a 12V one for about $75. If its for working with Air Tools you might be okay for a little while on the inverter but little compressors don't run Air Tools very well. Obviously the Generator or shore power will run it for as long as you have gas.

Coffee Pot - Get a french press, either boil the water with a camp stove or get a jet boil type cooker. coffee tastes better, takes the same amount of time, and uses no electricity.

25W lights. what kind of lights? LED flood lights for on the outside of the camper? or just like lantern type lights? if not LED get LED and save some watts.
 

dwh

Tail-End Charlie
So now, with a $2k budget, you can buy a Honda or Yamaha inverter-type gen (MUCH quieter), a couple GC batteries, a charger and inverter and maybe have something left over for solar.

For this situation, I'd choose a Yamaha ef2400 over a Honda eu2000.



(FYI: The fuel efficiency of inverter-type generators is a bit of a myth. They are not actually more fuel efficient. In terms of watts per gallon of fuel, a normal (synchronous-type) generator is more fuel efficient.

But...a syncronous generator cannot throttle down based on load. It runs at full speed even when only at 1/4 load. Being able to throttle down according to load makes the inverter gen run longer on a gallon of gas, even though it produces less watts per gallon.

If you flip the switch to turn off "economy mode", the Honda burns along at 5,000 rpm full throttle, whereas a synchronous gen runs at 3,600 rpm.

According to Honda's published numbers, it gets its best efficiency at 1/4 load (400w). It will run 9.5 hours on 1.1g of fuel at 1/4 load.

So...

400w per hour x 9.5 hours = 3,800 watts
3,800w ÷ 1.1 gallon = 3,455 watts per gallon

A decent portable syncronous can do 5,000 wpg (if consistently loaded to 50% or more). (There are small diesel syncronous (truck or trailer mounted - NOT portable) gens that can do over 15,000 wpg.))
 

Ozarker

Pontoon Admiral
Then, as to planning out a system;

Looks like we look at the highest requirement first, in this case, AC, at this time it's not practical to use batteries, so that's a genny thing.

No one wants to run a genny 24/7, it would also take a high quality, industrial type generator to do that, which would be big bucks. Not to mention fuel consumption that could run 10 or even 20 gal. all day. Nope!

In this case, the second big consumption function is the micro, that runs for seconds or for less than 4 minutes generally. I'm seeing the relationship of time power is needed to Ahr of storage.

An inverter twice the size you'll need seems to take care of surges when equipment starts up or kicks in for a heavy load.

Seems like the trick now is to top off the battery at the optimal time, as I understand it, some batteries can use a constant charge, some are better to draw down and then recharge, I'm not sure which s best for what......yet.

So, we can use the genny when running to provide extra juice for charging and then there is solar that seems to take up the slack.

Looks like with good power management you can live off solar, without AC, (you could do AC but that would be a very large bank and array of panels we don't have room for in a van.

Let's assume the genny has a 12v charger, I will carry another one just for grins anyway.

I'm keeping the cost of the genny under $400. There are several to choose from, including Champion, Sportsman, HF and others around the 3000 watt mark.

Wat I'm finding is that there is no better battery system for raw storage capacity at a reasonable price than 6V golf cart types. A couple issues with those, they are wet batteries requiring maintenance, they weigh more, give off gasses and if one goes bad, you have 6 volts left.

Part of that can be solved with another 12V back up house battery, now you have 3 to charge and wire up. You can get these for about $120 each, so there is $360, call it $400 with runs of wire for the battery bank.

Don't know the cost of that blue sea switch, but that leaves us either $300 for solar or $1300, depending on which budget you look at. Even a small solar battery charge/tender can help, but we'll bump the budget for more solar.

Since, in this caee we have a genny, maybe 100 watts of solar would do the trick, we can always add more later.

Now the question, what equipment do we need to put this together? Charger, relays, isolators, bus bar, connectors, fuses/holders, wire and meters?

Experts, what say you? :)
 

Ozarker

Pontoon Admiral
No can do.

When batteries are tied into a full-time bank, they must be as identical as humanly possible. Same brand, type, size, age - hell even the same production batch if possible.

In a full-time bank they all live, wear out and die together as one big battery. If one is different, it will do more work and wear out sooner. This will then cause the rest to end up doing more work.

End result - premature failure of the whole bank.

(This does not apply to batteries only tied during charging - that's no problem.)

You could keep the trolling battery separate and split loads. Like 12v lighting on that, and the 120v inverter stuff off the big bank.

Sorry, that was the plan not to draw from one larger bank, the 12V should be on its own except for charging and even then, it may be better to charge what is needed.

Thanks for pointing that out!!!
 

Ozarker

Pontoon Admiral
if you only want to spend $1000, plan on only running the AC, Coffee Pot, and microwave when on shore power. You don't have enough to buy a good quiet generator and do the 12v set up. My suggestion

Trolling Motor Battery (you say you have 1, so that will work for now) - $0 since you have it
Battery Tender charger. $80 - Will need to add in a power inlet plug if you want it mounted on board. that is another $15, figure some wiring/connectors for this and just call it $100.
Solar Charge Controller and Solar Panel - Cheap version $150 from Harbor Freight. Decent stuff $300 from Amazon. Both will get you 100-200 Watts of charging.
Misc Wires/Connectors, ports fuses ect for 12v Power - $75.
1500 Watt Inverter - $400+ for pure sine wave, $100 for Mod Sine Wave.

Thats $425 for the cheap stuff to just get the power system set up, $875 for decent stuff.

Suggestions on what you plan to run.
Fridge - Will run fine off the battery set up above.

AC- is what it is but you are going to need shore power or a generator if you want to use it. The generac IX2000 i had worked well but was much louder than the honda and will run the 6000 BTU window shaker that I have at home. The generacs are only like $500 so if you get the cheap stuff and the generac generator you are still under $1000 but will likely need to upgrade/replace down the line.

Microwave - Forget it. There are other ways to heat food. Grill, Camp Stove, ect.

Air compressor - what is this being used for? just filling tires? get a 12V one for about $75. If its for working with Air Tools you might be okay for a little while on the inverter but little compressors don't run Air Tools very well. Obviously the Generator or shore power will run it for as long as you have gas.

Coffee Pot - Get a french press, either boil the water with a camp stove or get a jet boil type cooker. coffee tastes better, takes the same amount of time, and uses no electricity.

25W lights. what kind of lights? LED flood lights for on the outside of the camper? or just like lantern type lights? if not LED get LED and save some watts.

Great comments, thanks!

Well, most of the travel time is on higways, meals on the road, momma says microwave, so it's a microwave.

I agree, fire is your friend, not so much in a moving van.

I'll probably bust lose for a 12V coffee pot, slower but we can wait.

Generally, the compressor is for tires, I have air tools but probably don't "need" them on trips.

Yes, I'll go with LED, the 25 watts included a fudge factor on the lighting circuit, who knows what little thing she might want to plug in.....

BTW, not mentioned, the genny will most likely be on the trailer (unless I add a rear rack) with fuel, I will fab a generator box to get the dbs down to an acceptable camp ground level, so I'm not concerned with a state of the art Honda at 3X the price. :)

We might be glamping instead of hard core camping, that's what us old folks do, LOL
 

Ozarker

Pontoon Admiral
So now, with a $2k budget, you can buy a Honda or Yamaha inverter-type gen (MUCH quieter), a couple GC batteries, a charger and inverter and maybe have something left over for solar.

For this situation, I'd choose a Yamaha ef2400 over a Honda eu2000.



(FYI: The fuel efficiency of inverter-type generators is a bit of a myth. They are not actually more fuel efficient. In terms of watts per gallon of fuel, a normal (synchronous-type) generator is more fuel efficient.

But...a syncronous generator cannot throttle down based on load. It runs at full speed even when only at 1/4 load. Being able to throttle down according to load makes the inverter gen run longer on a gallon of gas, even though it produces less watts per gallon.

If you flip the switch to turn off "economy mode", the Honda burns along at 5,000 rpm full throttle, whereas a synchronous gen runs at 3,600 rpm.

According to Honda's published numbers, it gets its best efficiency at 1/4 load (400w). It will run 9.5 hours on 1.1g of fuel at 1/4 load.

So...

400w per hour x 9.5 hours = 3,800 watts
3,800w ÷ 1.1 gallon = 3,455 watts per gallon

A decent portable syncronous can do 5,000 wpg (if consistently loaded to 50% or more). (There are small diesel syncronous (truck or trailer mounted - NOT portable) gens that can do over 15,000 wpg.))

You the man !

I bumped the budget for an earlier poster who said a thousand wasn't going to cut it basically, but that is the goal, it might go over. But, let's talk about this with a larger budget as many might be more hard core than myself or other newbies trying to get things set up.

Seems the first dollars need to go to batteries, then generator, then solar, but that's just me :)
 

dwh

Tail-End Charlie
I would seriously consider a propane kit for the generator.

http://uscarburetion.com/

The fuel doesn't sit in the carb and gum up between trips.
The fuel doesn't go bad sitting around.
Propane is usually cheaper if you get it from a proper propane shop at two bucks a gallon instead of those trade in deals or U-Haul at six bucks a gallon.
It automatically compensates for altitude.
A couple 10g propane tanks will get a longer run time than the 4 or 5 gallon tank on a 3k generator.

Downside, can't just fill up a couple jerry cans anywhere you want.
 

SoCal Tom

Explorer
An EU 2000 Honda generator would do it. You can run the generator while driving, it just needs to be mounted to the bumper. A simple method would be a hitch mount basket or mount to the tonque of your trailer. I run a 5K btu window AC with an EU1000, but to make coffee and run a microwave you would need the 2KW unit. If you want solar, dump the AC and the Microwave. FWIW, I had a 5K BTU A/C unit in the rear window of a E250 van. The rear bumper was extended about 18 inches, it carried a 4KW coleman generator ( loud as hell but cheap). Just had to start the genny before we hit the road. It cooled the rear of the van on the road in the desert while the cab air cooled the front.
Tom
 

Ozarker

Pontoon Admiral
I would seriously consider a propane kit for the generator.

http://uscarburetion.com/

The fuel doesn't sit in the carb and gum up between trips.
The fuel doesn't go bad sitting around.
Propane is usually cheaper if you get it from a proper propane shop at two bucks a gallon instead of those trade in deals or U-Haul at six bucks a gallon.
It automatically compensates for altitude.
A couple 10g propane tanks will get a longer run time than the 4 or 5 gallon tank on a 3k generator.

Downside, can't just fill up a couple jerry cans anywhere you want.

I'll now consider that! I did look at a few and they are more pricy, I thought about the fuel savings and that alone didn't justify it in my mind,

I was wondering about the altitude, thought so but wasn't sure, so if you say so.....that's a big plus.

I dislike having to mess with carbs due to bad fuel, getting gummed up, it's never ending with mowers and weed wackers and a genny is just another maintenance thing......

So, the other points you made are significant, I'll reconsider propane! :)
 

Ozarker

Pontoon Admiral
Verkstad, noted and I'm taking an additional charger, maybe two. One real charger and a trickle thingy. Which reminds me, I need to fire up my motorcycles!

Tom, I may only have 5 or so years left to travel and camp, it's an age thing. In 10 years I may not be able to pull a starter on a genny, much less lift it.......that's why I'm not sinking $$$$ into this project, there is little pay back for me.

Now, it's good to mention the higher budget route, with a Honda, others who have longer to enjoy the adventure should consider the upscale version.

I don't really suggest going the cheap route, but my pay back time is limited and I know there are many newbie young members starting out that are on a limited budget, so if it is reliable (somewhat) and inexpensive all the better.

Two gennys I'm considering now are the Champion and the Winn, but others can still be in the race.

Now, what about all the gizzmos that are needed to make all this work? Suggestions or what are you using? :)
 

Forum statistics

Threads
185,534
Messages
2,875,622
Members
224,922
Latest member
Randy Towles
Top