Help me evaluate my electrical needs for full-timing
- Thread starter jaross
- Start date
Cool! that build thread has some good info, thanks! What is the reason you decided to do just diesel and solar?
I am thinking going that elaborate with PV solar and battery maybe too cost prohibitive for me right now, considering the more affordable propane option!
dwh
Tail-End Charlie
Solar/battery/electric is good for pretty much everything, except making heat. For heat, burn fuel (stove, hot water, cabin heat).
I would go with an electric fridge (with danfoss variable speed compressor), but propane stove, and either propane or gasoline for heat.
That should simplify the electrical calcs.
Fair enough! What made you go with induction? Some say its inefficient others say it is very efficient.. It looks like if I crank it up to high all the time that it COULD use a lot of power...
dwh
Tail-End Charlie
Well, it is a stove. There aren't any flammable materials within a couple feet of the flame.
But whatever floats the boat. As long as you've got the space for the batteries and some way to charge them, go for it.
java
Expedition Leader
I looked at induction, but I found it just ate too much batteries for me. My bank was big enough that I didn't want to dedicate more space and weight to it. Propane is the easy button for cooking.
Im installing a shunt tonight so I should be able to track my usage soon, Fridge is 120/12v (not connected to 120 atm) and that and heater fan are the biggest draws Im guessing.
Im installing a shunt tonight so I should be able to track my usage soon, Fridge is 120/12v (not connected to 120 atm) and that and heater fan are the biggest draws Im guessing.
DiploStrat
Expedition Leader
Lots of Questions
and I have lots of answers, but I would suggest that you start reading here: https://diplostrat.org/documents/ You will find articles and slide presentations on almost all aspects of building a lead acid battery system.
Basically:
-- You size your electrical system to your loads. In my case, air conditioning, microwave, cabin heat, fans, computers, cameras, cooktop, music, etc.
-- Then you size your battery bank for the number of days of autonomy that you require. In my case, four days without engine start or sunlight. EDITED TO ADD: Also consider battery life. Most apply the 50% rule, that is, battery never drops below 50% charge. Other option would be to discharge 80-90%, but replace batteries more often. In my case, my normal usage is only 20% or less. Prolongs the life of expensive AGM batteries.
-- Then you size your recharge, in my case, 250A of alternators, 500w of solar, and 125A of 110v shore power.
As always, YMMV.
Remember - all of your loads are powered by your batteries, all the time. The alternators, solar, etc., merely recharge the batteries.
Final note: We did not use propane to avoid issues with adapters in various countries. Defensible decision, but I know folks who have traveled all over the place and would argue that $100 worth of adapters is cheap. (And we do carry a small gas grill as you can't use charcoal in the Western US.) We also have a diesel stove but it is slow to heat, slow to cool, and thus most useful during the winter.
Again, YMMV.
and I have lots of answers, but I would suggest that you start reading here: https://diplostrat.org/documents/ You will find articles and slide presentations on almost all aspects of building a lead acid battery system.
Basically:
-- You size your electrical system to your loads. In my case, air conditioning, microwave, cabin heat, fans, computers, cameras, cooktop, music, etc.
-- Then you size your battery bank for the number of days of autonomy that you require. In my case, four days without engine start or sunlight. EDITED TO ADD: Also consider battery life. Most apply the 50% rule, that is, battery never drops below 50% charge. Other option would be to discharge 80-90%, but replace batteries more often. In my case, my normal usage is only 20% or less. Prolongs the life of expensive AGM batteries.
-- Then you size your recharge, in my case, 250A of alternators, 500w of solar, and 125A of 110v shore power.
As always, YMMV.
Remember - all of your loads are powered by your batteries, all the time. The alternators, solar, etc., merely recharge the batteries.
Final note: We did not use propane to avoid issues with adapters in various countries. Defensible decision, but I know folks who have traveled all over the place and would argue that $100 worth of adapters is cheap. (And we do carry a small gas grill as you can't use charcoal in the Western US.) We also have a diesel stove but it is slow to heat, slow to cool, and thus most useful during the winter.
Again, YMMV.
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DiploStrat
Expedition Leader
Thank you for the kind words. While all of the documents are (I hope) correct, do check the dates. The newer ones benefit from about two years of real world experience.
And remember that lithium batteries can be very different.
And remember that lithium batteries can be very different.
luthj
Engineer In Residence
We wanted a single fuel camper, because getting propane fills on the road in South America can be hard. Induction is very efficient, but electrical needs must be balanced with charging. I find a simple meal for two uses 15-35 AH. A more complicated meal can use 50 AH. For a USA based camper, propane makes lots of sense. Look at the truma water and air combo heaters using propane. A propane stove also should be heavily considered. There is some great discussion on the sprinter source conversion forum. Lots of different approaches.
broncobowsher
Adventurer
Couple of thoughts (and I did skim some of the later posts)
If you want to run the induction cook top, start the engine. Trying to bank that much battery power is crazy. But the alternator will keep up just fine.
The other is the fridge value looks high. Not sure what fridge you have picked. My 10 year old ARB Freezerfridge draws under 3 amps when it is running. So summer in freeze, that is all the time. In fridge, way less but dependent on outside temp. Guessing 10~60% duty cycle on average.
If you want to run the induction cook top, start the engine. Trying to bank that much battery power is crazy. But the alternator will keep up just fine.
The other is the fridge value looks high. Not sure what fridge you have picked. My 10 year old ARB Freezerfridge draws under 3 amps when it is running. So summer in freeze, that is all the time. In fridge, way less but dependent on outside temp. Guessing 10~60% duty cycle on average.
I had not decided on a fridge yet. I am not sure what size I should choose (which is a different discussion). Mostly I will be traveling with myself and one other person. I was hoping for 5 cubic feet, but maybe thats overkill. I see many with smaller fridges!
As for starting the engine, I would like to avoid idling the engine as much as possible. I want to treat it nicely and have it last a long time!
broncobowsher
Adventurer
It's hard data to find. I lost the link I had. But Engle (who my ARB freezerfridge is a rebadged version) has published power consumption curves for there models. Bower used based on desired temperture inside and ambient outside.
If you still want the inductive cook top, and running the engine to power it isn't going to cut it for you, look at a small cheap generator.
Batteries and solare work great if you can keep the wattage reasonably low, in a few watts range. When you start asking for hundreds of watts, or multiple hundreds, you are asking to way too much for a small vehicle based system. Keep in mind a perfect conversion that it takes 746 Watts to convert into 1HP.
If you still want the inductive cook top, and running the engine to power it isn't going to cut it for you, look at a small cheap generator.
Batteries and solare work great if you can keep the wattage reasonably low, in a few watts range. When you start asking for hundreds of watts, or multiple hundreds, you are asking to way too much for a small vehicle based system. Keep in mind a perfect conversion that it takes 746 Watts to convert into 1HP.