MacGyver's Miscellaneous Mental Meanderings

[James.]

Re: MacGyver's Miscellaneous Mental Meanderings

I work for Meritage Homes (national home builder) and some moron set up our end of year at the end of the year. Which means the push is on. We are scheduled to close 26 homes in December in my community. I want to take a week trip in Jan. to recover but I can't do it if I don't get my stove project built and working....which I don't know if I will have time it build because we have 26 closings in Dec.

[Happy Joe]

Re: MacGyver's Miscellaneous Mental Meanderings

If I remember (pre-retirement employment) correctly; 'tis far better to be too busy than to worry about Christmas layoffs...

Enjoy!

[05Kingquad700]

Re: MacGyver's Miscellaneous Mental Meanderings

I was going to do a thanksgiving trip, but my daughter is in the middle of the crud going around. So i am just planning mods to be done. Going to do an axle flip mood, new mattress mod. My bunk is 50", little smaller than standard full size. So i will order a memory foam and cut it down. I want to redo the trailer tounge and add a deck big enough to hold my batteries and my generator.
Trying to decide if one 100 amp hour battery is enough or if i want to add a second

[Happy Joe]

Re: MacGyver's Miscellaneous Mental Meanderings

Trying to decide if one 100 amp hour battery is enough or if i want to add a second

I went through that decision cycle several times trying to get solar to work...

For me (because I don't us much electricity;
A single 450 lumen LED bulb + tunes (stereo) for a couple of hours per day, 35 amp hours is enough...
If I try to bring the portable fridge then I can run for just over 24 hours, 'cause it draws more power... need more battery.

Measure your amp draw for each device and over estimate (be generous) the time used during the whole trip; then multiply the estimated time, times the amp draw = amp hours
Add these numbers together for all your devices for the entire trip this is your estimate total usage ... if this exceeds by very much 1/2 of your battery capacity in amp hours you need more battery or to reduce the time the devices are used (or to consider recharging part way through the trip)...
To keep from damaging a lead-acid battery; don't run it below 50% (some say 25%) charge (much or often). 1/2 of my 35 AH battery is 17.5 amp hours (I typically exceed this on a 3-4 day trip so I recharge it using solar (PITA) or a generator and good, multi stage, battery charger or, if all else fails, the vehicle engine and alternator.

Running the battery below 50% (or 25%) charge slightly decreases its life time so you can do it occasionally and not do much damage (not sure how old this 35 AH battery is but its got to be close to 5 or 6 years now and still works very well.

Storing a partially charged battery is very hard on it; leads to sulfate crystals clogging the plates, so I recharge all the lead acid batteries, to 100% charge; before and after each trip and every month or so, during the off season.

To be able to use the portable fridge, without driving everyday, I figure that I would need at least a 100AH battery (50 available amp hours; that 50% discharge limit hurts) then would need to recharge it every 2-3 days using the generator and battery charger.

Hope it helps...

Enjoy!

[toedtoes]

Re: MacGyver's Miscellaneous Mental Meanderings

My optima is 75ah. My RV fridge doesn't use any battery power, so I only need it for lights, water pump, charging cell phone, kindle, mp3, etc. And I have battery puck lights set up because I prefer them to the overhead lights - so I only use my overheads when I cook or have visitor(s) and such.

I can go 10 days without denting my battery - no recharging needed.

Most newer RV fridges need battery power now, so if I could afford it, I'd put in the two 100ah batteries. Better to have more than less.

[MacGyver]

Re: MacGyver's Miscellaneous Mental Meanderings

My thought would be to go to two batteries. In my mind, if there's any doubt whether or not one battery will work for you, doubling your reserve lays that doubt to rest. Plus it's easier on the batteries because you lessen the risk of depleting them below that dreaded 50% level. I realize you have a generator that can top a single battery off, but if you're like me, I try to run that as infrequently as possible.

[Happy Joe]

Re: MacGyver's Miscellaneous Mental Meanderings

Yup! there are many ways to skin this cat; I went with the generator to recharge the fridge battery simply because I didn't want to modify the vehicle electrical system to install a dc to dc charger (I have recharged batteries from vehicles many times but I, really, don't like the lack of charge control, or inefficiency of an inverter+chatrger combination... If really pressed to use a vehicle I would, likely, do something with a disconnectable, current limited, heavy current, solar charge controller, perhaps with some added filtering on the vehicle alternator.
The easiest and simplest way to tell if you need more battery is simply to use it on a trip and monitor the charge, periodically & very roughly with a digital volt meter; when it gets around 11 volts its getting , perhaps, uncomfortably low.
Some folks consider 10.7 volts to be flatlining the battery and possibly doing some damage, however for test purposes; drawing a battery down, too low, a couple of times probably wont hurt it much, as long as it gets recharged relatively quickly (storing a low battery can kill it).

Since I prefer to travel compactly I won't really consider just adding more 100AH batteries, for myself (others are different); multiple batteries are heavy (until lithium gets affordable) and you don't get that much additional power for the weight and hassle. given the weight volume trade offs I opted for the smallest propane genny that I could find to do my recharging (not necessary, for me if I don't bring the fridge... for quickie weekenders the cooler and small tent battery, is much more practical.

Enjoy!

[MacGyver]

Re: MacGyver's Miscellaneous Mental Meanderings

I know what you mean about the weight! I'd downsized from group 27 deep cycles to group 24s and even that turned out to be more than I wanted to lug around. I'm currently running two 55 AH SLAs, looking to get a third. And the whole lithium thing is driving me crazy. I've been reading for a couple of years now how the prices are going drop drastically, and yet, 100 AH lithiums are still around $1,000 plus. On top of that, I'd have to get a different solar controller that has a lithium charge cycle. I've also looked into DC-DC chargers - too expensive for what little I'd use it. Solar is fine for warm weather trips but not so efficient in Winter, which is why I bought the genny and an 8 amp charger because the output on the generator isn't regulated. It's amazing how expensive all this experimenting and changing gear can get, isn't it?

[Happy Joe]

Re: MacGyver's Miscellaneous Mental Meanderings

...Expensive; But, ITS Educational!...

and fun to play with.


Remember; testing is best done while CAMPING.

Enjoy!

[toedtoes]

Re: MacGyver's Miscellaneous Mental Meanderings

For me, I don't want another engine and I don't want the noise. So I have minimized my electrical use so I can go the 10 days on one battery. If needed, I would add another battery before adding a generator or solar. Of course, I don't have to lug around the batteries since I have the clipper and FnR.

[05Kingquad700]

Re: MacGyver's Miscellaneous Mental Meanderings

Just so you guys know, i have been an electrician since 97.

The only reason i may need a second battery is maybe for the furnace on colder night's i could use the space for something else. But any winter camping will be done in a campground with full hook ups, so i am thinking i can skip the second battery. And my fridge is only a 2 way. 120V or propane no 12v what so ever.

[toedtoes]

Re: MacGyver's Miscellaneous Mental Meanderings

And my fridge is only a 2 way. 120V or propane no 12v what so ever.

Even though it doesn't run on 12v, most newer (last 20 years?) RV fridges have control panels that run on 12v. That is so when you are on propane without hookups, the control panel can still work.

If your fridge has an "auto setting" that will select between propane or electric, it absolutely needs 12v to operate.

[05Kingquad700]

Re: MacGyver's Miscellaneous Mental Meanderings

This is why i pretty much quit posting on this forum. Everyone knows everything, even though they don't have a clue about my trailer.

[toedtoes]

Re: MacGyver's Miscellaneous Mental Meanderings

This is why i pretty much quit posting on this forum. Everyone knows everything, even though they don't have a clue about my trailer.

I take exception to this. I pointed out a common misconception about RV fridges. If it doesn't apply to your fridge - fine. But for other posters, understanding that some 2-way fridges DO use 12v power is important. I posted a statement about fridges, not YOUR fridge in particular.

[05Kingquad700]

Re: MacGyver's Miscellaneous Mental Meanderings

Take exception all you want, i am adding you to my ignore list to improve the quality of my experience on this forum.