Questions on Setting up an auxillary power system in my FWC

[Rockcrawler]

I'm working on "tweaking" the power system in my FWC. I will be adding a DC to AC Inverter as well as a few other odds and ends. I've been using the spreadsheet from the wander the west site to calculate my total amp draw. It looks like I will have 2 separate systems, one in the truck and one in the camper.

From the factory, the Dodge comes with dual batteries that from what I can tell are traditional starting batteries with some reserve capacity (to run the grid warmers for the Cummins I assume). It looks like I have a total of 375 Amp hours between the 2 if my calculations are correct. Someone that may know better can tell me if my calculations are sounds. Each battery is rated at 150 reserve minutes, but do not list amp hours. From what I found here.
300 reserve minutes equals about 375 amp hours.

I only need about 32 amp hours/day for what I want to run off of the truck's factory system so I theoretically can run these accessories for 5 days w/o dropping below 50%. Although, I'm sure I don't want to run these batteries down that far since they also must start the truck... I don't see any reason that 2 or 3 days w/o moving would be an issue though.

Now for the camper system, there is currently 1 deep cycle battery installed that is charged off of the factory system, but has an isolator in place to disconnect it from the truck when the truck is shut off. I need to research the battery that is in there (it was installed by the previous owner) to determine its amp hour capacity. I'm guessing it is somewhere in the 90 to 100 range though and my daily demand is ~110 amp hours. So I have about a half day's capacity with the current single battery to keep it above 50%.

So... the million dollar question... What is the most logical step to keep everything running for 2 to 3 days?

Add another Deep cycle battery or two?
Generator?
Solar?
Some combination?

Have at it ladies and gents... I look forward to your insight.

Kyle

 

[goodtimes]

I'd seriously consider adding a 4th battery....that would be a 2nd in the camper. You don't want to mess with the 2 in the truck. Keep 'em for starting. Solar would be a good addition...I'll be adding a small flexible panel to the jeep at some point (after the $900 electrical upgrade that is starting this weekend). Stop by to help me lift a dana 60 tomorrow. I'd avoid a generator...to darn noisy....kind of ruins the ambiance, ya know?

 

[Mike S]

I think you should find out how many times you can safely discharge your current batteries before they are dead - unable to hold a charge any longer. Most starting batteries cannot be deeply discharged and survive. Combination starting/deep draw batteries have limitations - usually 200 to 300 discharges to 50% level before they are toast.

For maximum battery AH capabilities you might consider two 6V 425 AH golf cart batteries and a solar trickle charger and controller. This combination will cost you approximately what a Honda EU200i generator costs, but the generator is lighter (weighs less than one of these batteries) and takes less maintenance. Soo.. I would get the generator and use that to charge the batteries whenever needed.

Just a thought.

 

[Rockcrawler]

I'm guessing you mean 245 AH... if not, where can I find the 425 AH? The highest I've been able to find is 395 AH in 6V.

Another thing to consider is that I either need to carry a gas can for unleaded for the generator or go through the additional cost of a propane conversion on the generator. I already carry Diesel and Propane... I'd rather not have to bring gasoline as well.

Kyle

 

[Tucson T4R]

Your coming by to look at my set up but I run two Deka AGM 105 AH batteries tied together in one bank in my trailer. I have a 20 amp Xantrex smart charger that will charge the batteries when 110V AC Shore power is available. Plug in at home or from my generator in the field when needed. A solar charger would be nice but I haven't invested in that option yet.

I run an 84 Qt Weaco fridge which draws a good amount of power when conditions are hot. My first shake down trip a couple weeks ago with this new battery system worked great and I was out for 3 days, never used the generator and still had about 12V showing on the batteries when I broke camp on the 3 day. Seems to be a solid set up with plenty of power for my needs.

 

[Mike S]

I'm guessing you mean 245 AH... if not, where can I find the 425 AH? The highest I've been able to find is 395 AH in 6V.

Another thing to consider is that I either need to carry a gas can for unleaded for the generator or go through the additional cost of a propane conversion on the generator. I already carry Diesel and Propane... I'd rather not have to bring gasoline as well.

Kyle

There are a number of 6V deep cycle marine batteries available - well beyond 500 AH - big at a cost and too much weight. Here is a source for Surrette's reliable marine batteries... go to section D of the spec table the battery is a 410 AH 6V. I will find the other one 425 AH - it's in my bookmarks somewhere...

http://www.surrette.com/?q=node/13

 

[Rockcrawler]

Wowza... that is an expensive battery! :smileeek:

 

[Mike S]

Yes, it is. The only way to make a true deep draw is to use large, thick plates. The bigger and heavier the battery, the more AHs and the higher the price.

Marine batteries are made to take a beating. Solar and other pure storage batteries are made for stationary applications.

I think a small genset for charging is the way to go. It will cost less, be lighter, and has more applications than the true deep draw batteries. Most small gas powered generators can be converted to propane pretty simply, if fuel is an issue. There will be a slight reduction in output.