Living full time in suburban - solar advice needed

john61ct

Adventurer
Keeping batteries enclosed is strongly suggested. If its flooded batteries, not enclosed is serious hazard.
Be sure your enclosure is freely ventilated to outside.
No, the serious hazard (explosion) is enclosing without venting.

Leaving them open in the living space is a matter of preference, lots of vehicles put FLA batts under a seat NP.

Some don't mind the smell, or having to occasionally run the fan or crack the window.

But sealed and vented outside is the ideal.
 

john61ct

Adventurer
I wonder if anyone makes a small under hood gas powered generator?

Seems like there might not be much of a market for it, but I could see contractors using something like this, who knows who els?
Just choose a vehicle that has plenty of room.

I've seen trucks with a 4kW gennie mounted in the engine compartment.
 

john61ct

Adventurer
Ideal is a small Honda inverter genny, very quiet.

With an 80+AH shore charger, able to be derated, can also plug in at work or when visiting friends.

High-CAR AGM bank like Lifeline, Odyssey or Northstar needed to reduce runtime. Plus solar, doesn't need to be a lot if you run the genny in the morning, get bank up to 80-85% in the AM, then solar finishes the long tail to 100% Full for 4-5 hours.

Or Firefly Oasis, $500 per 100 AH. Doesn't mind some PSOC abuse, so no solar needed.

Ideal is LFP, no need to get to 100% ever.

But 5+x the price.
 

john61ct

Adventurer
The way Engel list it spec of consumption is odd.

Or averaging its run & idle times, do they really mean 1-2Ah per hour ?

AH per hour is correct.

Amps per hour makes no sense.

3-6A is normal while compressor is running, if temp difference low and doors rarely opened, compressor runs maybe 20% of the total time.

Hence WAG estimate of 1AH per hour.

Hot weather used as a freezer **lots** more.

Add insulation and active venting of hot condenser area, efficiency rises dramatically.
 

Rando

Explorer
AH per hour is correct.

Amps per hour makes no sense.

3-6A is normal while compressor is running, if temp difference low and doors rarely opened, compressor runs maybe 20% of the total time.

Hence WAG estimate of 1AH per hour.

Hot weather used as a freezer **lots** more.

Add insulation and active venting of hot condenser area, efficiency rises dramatically.

I think you mean 1-2 amps average current draw. Amp-hours per hour is just amps, and doesn't make much sense.
 

rayra

Expedition Leader
Have any pictures of that? Low profile would be huge for us.

In my build topic, in my sig. Mounting frame is just a sketch right now, but I should have the time and money to build it around Thanksgiving. There's also links in that topic to my other build topic about a roof rack deck, shading the vehicle roof, as well as my platform / drawer project, which could be readily adapted to hold a bank of batteries. Their height is close to my platform height.
 

john61ct

Adventurer
I think you mean 1-2 amps average current draw. Amp-hours per hour is just amps, and doesn't make much sense.
No, you are 100% wrong. Amps already are a timed measurement of **flow speed**, instantaneous, like gal/hour.

AH, or amp hours (no dash) are a measure of quantity, storage or usage, like gallons.

A fridge pulls 3A when the compressor is on. If it is on 100% of the time it would use 72AH per 24 hours. If it only cycles 1/4 of the time it uses 18AH per day, etc.
 

john61ct

Adventurer
Under the seat is enclosed. At least from explosion point of view. Under a typical upholstered seat would be fairly safe.
what makes it safe is the dispersal into a larger space.

If someone is sensitive to the occasional smell and ventilating is annoying, then a box vented to the outside is required.

Yes doing that is best from the start, but optional, can be done anytime.

A well maintained battery bank gives no surprises and should be replaced long before AH capacity has fallen below 70-80% of rated.
 

Rando

Explorer
What we are talking about here is the rate of energy consumption of a fridge. In reality what we should be discussing is Watts, but since we are assuming that the voltage is a constant 12V, we can use amperes with an implied voltage of 12V. An Ampere hour is 3600 Coulombs. An Ampere hour per hour is 3600 coulombs / 3600s = 1 ampere. Fridges are not different from any other electrical load - my lights draw 0.2A, not 0.2Ah per hour, my phone draws 1A while charging, my furnace is 1.2A while running etc.

I get it that fridges are a variable load, so may want to define an averaging period that is relevant to our system, in which case a 24h period would be a more relevant time period to average over. For instance the energy consumption of my fridge is rated by Indel at 360W/24h which is equal to an average of 1.5 Amps at 12V.

To continue your analogy below, say my car uses about 1.8 gal/hour while idling. So how much fuel does it use in an hour? 1.8 gallons, not 1.8 gal hours per hour.

No, you are 100% wrong. Amps already are a timed measurement of **flow speed**, instantaneous, like gal/hour.

AH, or amp hours (no dash) are a measure of quantity, storage or usage, like gallons.

A fridge pulls 3A when the compressor is on. If it is on 100% of the time it would use 72AH per 24 hours. If it only cycles 1/4 of the time it uses 18AH per day, etc.
 

john61ct

Adventurer
Fridges are not different from any other electrical load - my lights draw 0.2A, not 0.2Ah per hour, my phone draws 1A while charging, my furnace is 1.2A while running etc.
Yes nothing to do with fridges obviously.

More simply 100 AH is 100A "running for" or "over" one hour. Or 1A over 100 hours, 20A for 5 hours, 50A for 2 hrs, whatever, let's please not bring Mr Peukert into this.

Your lights draw (24*.2) AH per day if left on all the time, if it takes 45 minutes for your phone to charge that's .75AH of usage, when your furnace is cycling 75% of the time that's .9AH per hour.



To continue your analogy below, say my car uses about 1.8 gal/hour while idling. So how much fuel does it use in an hour? 1.8 gallons, not 1.8 gal hours per hour.

And AH are the static quantity (like coulombs), in this case gallons!

Amps are a rate (as you said, coulombs per second), so that matches your gallons per hour.
 

john61ct

Adventurer
But it's useful to show unbelievers why Amps, as a measure of flow rate, already have the element of time included,

hence why "amps per hour" makes no sense

and AH per hour makes perfect sense
 

Rando

Explorer
Your still yet to explain why current * time / time is not equal to current. As you correctly point out - the Ampere already has time in the denominator, which is also why you don't need to multiply it by time then divide it by time to get the rate of consumption. In physics this a basic technique called dimensional analysis.

I agree amps per hour makes no sense, that is why the correct unit is just Amps which was my point all along and is why the current draw of electronic devices is specified in amps.

Ampere hours per hour is not totally incorrect, it is just an unreduced fraction. It would be like using a unit such as ampere pounds per pounds (also just amps).

Anyway, this has run its course - you can use what ever units you would like.
 
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