help! smoke coming out

[wanderer-rrorc]

my ears....:drool:

In trying to size the house batteries of the van...

MAX looks like it will be while sitting (no shore no vehicle charging setup(yet))

fridge 5.4a 65w 24hr
lights (oustide)350ma 4w ea x4 (16amp) 6hr max
kids dvd 1500ma 18w 4hr max
led pods inside light .07a .85w ea x10 (.7amp) 4hr max
12vt fans 1a 12w ea x3 12hr run
ceramic heater (proly will find more efficient one..)..13a 156w 6hr max run

most will get run at night (heater rarely unless its really cold..and I'll shop for more efficent one)..

Im coming up with 25 amp/hr if its all on half the time (it wont..but better be more than less)

now im confused....what size battery do I need *IF* I also have a 20 or a 30 watt solar panel to recharge them?
http://www.affordable-solar.com/PU-30-Watt-RV-Kit.htm


what other solar systems would you recomend????

my brain hurts...im going to go soak it in rum for a bit...:coffeedrink:

 

[iigs]

my ears....:drool:

In trying to size the house batteries of the van...

MAX looks like it will be while sitting (no shore no vehicle charging setup(yet))

fridge 5.4a 65w 24hr
lights (oustide)350ma 4w ea x4 (16amp) 6hr max
kids dvd 1500ma 18w 4hr max
led pods inside light .07a .85w ea x10 (.7amp) 4hr max
12vt fans 1a 12w ea x3 12hr run
ceramic heater (proly will find more efficient one..)..13a 156w 6hr max run

most will get run at night (heater rarely unless its really cold..and I'll shop for more efficent one)..

Im coming up with 25 amp/hr if its all on half the time (it wont..but better be more than less)

now im confused....what size battery do I need *IF* I also have a 20 or a 30 watt solar panel to recharge them?
http://www.affordable-solar.com/PU-30-Watt-RV-Kit.htm


what other solar systems would you recomend????

my brain hurts...im going to go soak it in rum for a bit...:coffeedrink:

If I understand, you're saying you want to charge all of this with 30W solar and no vehicle charging system? It can't be done. In fact, I would say that it doesn't contribute enough to be worth adding.

Assuming you don't use the ceramic heater at all (maybe get a propane one?) and the fridge has a 10% duty cycle (runs one minute on, nine off -- might be reasonable if it's cold enough to need a ceramic heater, but I don't know), a day of the stated loads is 66Ah. Assuming the selected solar panels can put out 80% rated power for 8h/day (I don't know if this is realistic, but doesn't seem implausible in sunny environments, I guess), you'd need a system rated for 125 watts.

Lead Acid batteries do NOT respond well to being deep discharged. Here is a sample discharge curve, horizontal is discharge depth, vertical is lifetime cycle count:

The general guideline is that you want to ballpark 50% cycle depth. Since I can't find a 120Ah battery on affordable-solar quickly, lets just spec the 198Ah model. AGM batteries can take between 50% and 75% of their Ah rating as an upper bound on their charge rate. So, this could take 100-150a (lets say 132 to make the math really round) of charge from an alternator. That means, if you can provide it, it could recharge in 30 minutes from an alternator or generator source.

I don't know what your usage profile looks like, but if you can get away with running a 2kw generator or your vehicle for 30 minutes per day, it might be more sensible to do that than wrestle with solar.

On the other hand, the 165watt solar kit is only twice as expensive as the one you posted, and it would probably cover your needs for most days.

Again, this is predicated on not using the ceramic heater (and with not much headroom for anything else). Adding the ceramic heater turns the 66 Ah number into 144 Ah, making the problem roughly 2.5x the size.

In summary: Other heating + 200Ah of battery + 165w of solar = possible success.

Good luck!

 

[iigs]

In summary: Other heating + 200Ah of battery + 165w of solar = possible success.

I did some digging more digging and I'd like to revise this number slightly (and thank you for pointing me to affordable-solar.com!). Anywhere in the yellow in this map:

You might expect to get approximately 70% of the STC (Standard Test Conditions) ratings for probably 6 hours per day. The orange/red areas are probably higher. That bumps my 125 watt initial estimate (resulting in the 165w product recommendation) to 190w.

Reading the PDF for the cells used in that 165 watt kit, I'm not sure how they can claim it's 165w, when it looks like it's 160w theoretical maximum, but practically more like 140w.

At any rate, you're still in the ballpark there with my original load estimates. The next biggest consumer remaining is 36Ah of fans. If you can cut the 12 hour estimate to 8 hours the 190w requirement drops to 154.

I've never dimensioned solar power requirements before, so if someone can double check my work I would humbly accept the education.

 

[charlieaarons]

Do the arithmetic. You are talking 255 A-hr/24hrs. So you need at least 2 8D batteries (255 Ah each) to allow 50% discharge, assuming daily recharge.
You need at least 7-800 watts of solar panels, assuming a sunny climate!
Obviously electric heat is the biggest mistake, assuming recharge with expensive solar power.
You'd be way better off with the smallest diesel/petrol fired heater (Webasto or Espar/Eberspacher), it uses less very expensive electricity and produces much more heat.
Your fridge also accounts for a lot of power draw, will it really run 24 hrs/day? Is it a compressor fridge?
Assuming daily recharge, the "rule of thumb" is that one doesn't let batteries fall below 50%. Check the http://www.lifelinebatteries.com/ site.
And referring to the map above. Read the fine print, it assumes you tilt the panels at the angle of your latitude from the horizontal. Since they'll be flat, multiply the numbers by the cosine of your latitude. Cos 40 deg = 0.766

Assuming 33% duty cycle on fridge and 4A for fan on petrol/diesel 2kw heater 3 hrs/night, about 400W solar panels might do the trick, along with one 4D or 8D battery or two size 31s.
3 of these:
http://www.altestore.com/store/Sola...r-Sharp-ND-130UJF-130W-12V-Solar-Panel/p6721/
They will occupy 4.5 sq meters or 5X6.5 feet

The Webasto Air Top 2000 ST forced air diesel heater uses 9-22W (0.75-1.8A @ 12V) and puts out 2000W of heat.
http://www.webasto.us/am/en/am_rv_heaters_826.html

Charlie

 

[wanderer-rrorc]

WOW....Im seeing the heater being a NO-GO!!

the fridge we're lookin at is this...and Im not sure how they run...

http://www.compactappliance.com/FP4...P430,default,pd.html?cgid=Appliances-Freezers

 

[Martyn]

If you wire the house battery in as a second battery with charge coming from the alternator then things will start to make much more sense. The photovoltaics will elongate the time you can stay in a base camp before having to start up the engine to recharge the system.

Your biggest problem is solving the large amount of power required for your accessories. 5.4 amps for a fridge is a lot of power, to me it means either an inefficient fridge or a mis-interpretation of the specs. When you calculate the power required for a 12 volt compressor fridge you need to take into account how much of the time is the compressor running in a 24 hour period, and what the average power consumption is.

A compressor fridge will draw a large amount of amperage when the compressor first kicks in and then a lower amount as it's running. Our experience with the Engel 45 is that it averages 1.2 amps and hour over a 24 hour period. The specs for this fridge are 0.7- 2.5 amps.

If your outside lights are really pulling 16 amps then look at replacing them with LED lights, our work LED work lights pull 1.2 amps each. Your total power for 4 would be 4.8 amps.

I think most of the people who use 12 volt electric blankets use them to pre- warm the bed before they get in. I can't see you using it all night long. You would be much better off getting warmer bedding and using the heater less.

 

[LandCruiserPhil]

Here my little set up to give you a bench mark idea of what you need

Waeco CF-50 frig 48watts
Siemens(high quality) 55 watt solar panel
I live in one of the sunniest and hottest places on earth - AZ
My frig runs a lot in during the summer months(inside truck temps 140* during day)

My frig can run forever if my Land Cruiser is parked in the open and my single lead acid battery and panel can keep up.

Looking at your list you need 3 things IMO -
Less demand
More battery
More solar panel

Everything has variables as for efficiency , batteries, solar panels, and loads. You can run all the numbers you want but the best you can do is to get close and do some real world testing to see what works for you in your area.

 

[wanderer-rrorc]

my fear with adding engine charge is that it will fry the alt already on the van..its diesel so its already hauling 2 batts...but I think the one is only for the glowplugs..(need to do an amp read on it)...so that would give me one to run from (factory isolator)


I must be fudging some numbers guys...Im way out there...

lemme try and rope it in...

ditch the heater...maybe a 12vt blanket..(good bags too)..or 2...(kids)...but we dont plan on heading out when its too cold (below 30 at night)..course theres always me buring another pair of boots...:REOutCampFire03:


looking at 4 of these lights for the campsite/ vehicle worklights (2 on each side)

Maxxima M84400 LED low Profile Cargo Light
Finally! Real usable LED lighting! These lights produce a real light, great for areas where low power draw and maximum light output are important. Solar power, Wind Power, boats, Trailers, Campers and RV's etc.

Very low Profile, easy to mount with included screws, includes small switch in side.
Compact Thin Low Profile Design
Low Profile Surface Mount
Perfect for Interior & Overhead Use
Light Cargo & Compartment Areas
100,000 Hour Rated LED Life
3 Position On/Off Switch
12 Volt DC power, 350 ma
120 Lumen Light output


led 4 bulb pods (6) interior
http://cgi.ebay.com/12V-5-X-4-LED-P...emQQptZLH_DefaultDomain_0?hash=item5d26dbc0a8

White LED: 12000~14000mcd, 800k, ~70mA, ~0.85w
Temp: ~10F to ~100F
Operating voltage: 12Vdc (max 14Vdc regulated)

I have to search for less hungry refrigerators...43qt or there about in size..the engle shows it uses HALF the power the otherone does!! WOW..any recomendations on what to get?

I guess the kids DVD could be ran of the engine battery too...been testing it all day (stored without being charged for at least 8 months!!..ran 1h15min yesterday after charged..over 2hrs today after a charge...that should get them thru a movie a night (downtime) and if its rainin we're proably gonna either be in rainjackets or playin boardgames or somethin (hittin each other with sticks!!):jumping:

I appreciate everybodys help and info..keep it comin...I dont wanna throw alot of cash and then have to re-do it because I made a mistake..or have wasted it on too much that I wont use...

 

[spencyg]

my fear with adding engine charge is that it will fry the alt already on the van..its diesel so its already hauling 2 batts...but I think the one is only for the glowplugs..(need to do an amp read on it)...so that would give me one to run from (factory isolator)

I have the exact drivetrain and charging circuit that you do, and I have had no issues whatsoever with my alternator keeping up with the two starting batteries and the 210Ah house bank. My house bank is isolated from the starting circuit when the engine is not running, so drawing down the house batteries doesn't concern me greatly. I know for a fact that I can run my old compressor fridge (draws 4A when running, cycles every 15 minutes or so for 3 or 4 mintes), all of my interior lights (old school, not LED yet), laptop, intermittent water pump, intermittent air compressor (25A), stereo, and exhaust fan for 3 days of typical usage on a SINGLE group 27 105AH deep cycle battery before it becomes fully discharged. I now have two group 27s in the house bank and have not come close to hitting my capacity. This is without solar input. With solar, I probably could have stayed with a single house battery. If you really want to have an overkill system (which goes along with my standard operating procedure), a couple 27's or 31's combined with 100W input from solar will keep you alive and happy. I wouldn't go any crazier than that.

Spence