inverter, charger, battery bank add on for 5th whell

[prstlk]

We have been full time going on 4 years in a 39ft dp. We have loved the inverter system using 4 6V golf cart batteries, and the Magnum power managment controller. After the purchase of a "winter" home in the SW, we are moving back to a 5th wheel, as leaving the DP sitting for 4/6 months makes little sense. We purchased a used 5th wheel with a 5500 LP gennie and my questions are as follows.

I would like to have similar system in the 5th wheel. Battery bank, inverter/charger etc. I'm getting bits and pieces here and there on the net, forum boards utube etc.

Does anyone know of a comprensive book that can walk me through what I need to do. I have wired several houses, and wires electricity does not scare me.

Thanks in advance for any help.

If I'm on the page please dear moderator move my post.

I can't begin to tell all how the place has helped me since 07!

[pnichols]

Here's one price for the battery I linked to (I paid about $305 each for mine that I picked up locally):

https://www.wholesalesolar.com/9949473/fullriver/batteries/fullriver-dc115-12-agm-sealed-battery-12v...

P.S. I was going to buy Lifeline AGM batteries instead of these, but the Lifeline batteries specified a long term float voltage of around 13.2 volts. I float my RV's batteries at the stock RV converter's ~13.8 volts, so I had to look for a competitive AGM battery with a higher specified float voltage.

[neonjohn]

pnichols wrote:


You might want to also consider this battery model in your system - they are 115 AH each and are warranted for 5 years: http://www.fullriverbattery.com/product/batteries/DC115-12

Thanks. That looks like a nice battery. Any idea the cost?

pnichols wrote:

Regarding the squealing belt on your E350 while spinning it's alternator under load: There definitely must be a way to stop this. Our E450 has a 130 amp alternator and at times dumps over 70 amps (with the V10 idling) into our two paralled batteries of the type in my link above ... and there is no belt squeal.

Yes, the solution is NAPA's super-premium belt. I had the same problem with my last RV after I upgraded to a 130 amp alternator. The belt solved the problem.

The belt that is on the rig is of unknown vintage. One of the things on my list to fix.

Thanks
John

[MrWizard]

your multiplying and i'm dividing, you say the a/c is using 1640 va to produce 1134 watts of work

and i'm saying its using 2314 va to produce 1640 watts of work

i like your math better than mine, I hope you are correct

[pnichols]

neonjohn wrote:
Batteries

AGMs are the way to go. Wet cells are so last century. I have some AGM traction batteries (100 amp-hours, over 100 lbs of lead.) from the old AVS electric bus company in Chattanooga. They’re over 10 years, yet they discharge test at about 90% of rated capacity. I’m probably not going to use these because they are so large for the amp-hours. I’m currently looking at this battery, specifically 5 of them:

https://www.batterystuff.com/batteries/ups-telecom/universal-12v-110-ah-deep-cycle-sealed-agm-battery-ub121100-d5751.html

I have experience with this battery. Though it is made by the chicoms, it is a quality product. I’m still shopping for a better price for that class of battery.

You might want to also consider this battery model in your system - they are 115 AH each and are warranted for 5 years: http://www.fullriverbattery.com/product/batteries/DC115-12

Regarding the squealing belt on your E350 while spinning it's alternator under load: There definitely must be a way to stop this. Our E450 has a 130 amp alternator and at times dumps over 70 amps (with the V10 idling) into our two paralled batteries of the type in my link above ... and there is no belt squeal.

[neonjohn]

MrWizard wrote:
"So the watts are 120 volts * 13.5 * 0.7PF = 1134 watts. BUT. The generator has to supply the total volt-ampers or 1600 VA"

You are right that roof to a/c uses a lot of power
But your numbers are low

120*13.5= 1620 . 1620/0.7 =2314va

A poor pf means it uses more power not less
It uses 2314 va to do 1620w of work

Nameplate volts times nameplate amps yields volt-amperes on a less than 1 PF load. So.

120 * 13.5 = 1620 VA and not watts. To get watts, which is always less than VA when the PF is < 1.0, multiply by the power factor of 0.7. As I did. 1620 * 0.7 = 1134 watts.

John

[MrWizard]

my batteries are rated at 135 amphrs for an 8Hr rate/discharge
that 27 amps discharge per battery times 5 batteries
(new specs are 132 ampHrs)

in other words i can carry 135 amps (5*27) for 8 hours to total discharge

i have never done this, and never want to do this
and have no plans to run the A/C from batteries and inverter

i only post this to inform, there are batteries out there with the rated capabilities
mine are FIAMM 12FLX500

FIAMM 12FLX500

AND YES we use a generator during the day, the batteries and inverter supply our needs at night, residential fridge, tv, pc, fans, even electric blanket on the bed, MW for some bacon or hot danish, or coffee
but A/C is strictly from Generator power

i got mine surplus, new specs are slightly different than the ones listed for my version

[Sam_Spade]

neonjohn wrote:

I don't like to run the generator unless it will be on long enough to fully heat up.

Do you camp much in the winter time ?

10 minutes should be plenty, especially if it has a good load and it's not cold out.

Just the converter/changer provides a decent load if the batteries are down a bit.

When the morning low is 70 F, run your gen for 5 minutes under load.
Shut it down and check the temp inside the cover.
That's 5 minutes by the clock, not an estimate.

[Sam_Spade]

time2roll wrote:
Not sure I would install a big 2000 watt inverter if I had an on-board generator.
Maybe something like 300 watts is way easier to run or charge small items. For microwave, hairdryer, A/C just use the generator. Or do you need electric coffee before generator hours?

Some are perfectionists.
Some are obsessive.
Some need a "hobby".
Some don't realize what they are getting into.

I prefer KISS. That means a generator.
If you have a quiet one, "generator hours" are somewhat flexible.
And coffee will heat on the propane stovetop if necessary. 🙂

[MEXICOWANDERER]

Let's look at battery 5 hour rates. A high continuous discharge level skews ampere hour ratings. There is no magic answer. AGM + a Fort Knox budget is unavoidable. To create heat, exhange it by pumping through an orifice is anything but efficient. Unfortunately there are no alternatives.

[time2roll]

Ok and I cannot imagine using the mini-split air for such a short duration that the generator would not warm up. Battery powered air conditioning never seems to go very well.

I might even focus on a way to carry more propane if running the air for extended periods.

Did you have similar in the DP to run the air? That worked OK?

[MrWizard]

"So the watts are 120 volts * 13.5 * 0.7PF = 1134 watts. BUT. The generator has to supply the total volt-ampers or 1600 VA"

You are right that roof to a/c uses a lot of power
But your numbers are low

120*13.5= 1620 . 1620/0.7 =2314va

A poor pf means it uses more power not less
It uses 2314 va to do 1620w of work

Some people have talked about using mini splits
Maybe one 'on here' has done it
There are several on you tube who have done it with 'small trailers'
But they don't appear to be members here
And i have not seen it done on a larger RV
It seems the logistics of the floor plan and cabinets, bed etc prevents the efficient implemention doing that

[neonjohn]

neonjohn wrote:


The large inverter is primarily to run the minisplit generator. That it can run other heavy loads is just a convenience.

Oops, minisplit air conditioner.

John

[neonjohn]

time2roll wrote:
Not sure I would install a big 2000 watt inverter if I had an on-board generator.
Maybe something like 300 watts is way easier to run or charge small items. For microwave, hairdryer, A/C just use the generator. Or do you need electric coffee before generator hours?

I don't like to run the generator unless it will be on long enough to fully heat up. That way moisture from combustion won't remain in the crankcase and muffler.

The large inverter is primarily to run the minisplit generator. That it can run other heavy loads is just a convenience.

John

[time2roll]

Not sure I would install a big 2000 watt inverter if I had an on-board generator.
Maybe something like 300 watts is way easier to run or charge small items. For microwave, hairdryer, A/C just use the generator. Or do you need electric coffee before generator hours?