Solar Solution Adequate?
Hello, everyone! Pretty new to the Class A (2017 Newmar Ventana LE) lifestyle, I had the dealer install a 160 Watt Zamp Solar Deluxe kit, with a 30-Amp Controller, anticipating I would have a nee...
Forum Discussion
As was said, you have an absorption fridge, rather than a residential one, as it can run on propane. That is good in this case; it uses a lot less electricity (since the main energy to run it comes from the propane).
For RVs, 12V electric usage is commonly computed in amp-hours (Ah), an amount of charge transferred by one ampere over the course of one hour. (It's not really a measure of energy per se, but since the voltage is taken to be more or less constant at 12V it is equivalent in practice). An absorption fridge might use an average of 1A when it's running, or 24 Ah per day; some use a good bit less, and probably some more, particularly if they have fans that must run for them to operate. Miscellaneous constant loads like the LP detector and CO detector might use a few Ah per day. Most other things are somewhat under your control--you can decide when and how much to use them.
Incandescent lights are an amp or two per bulb; LED lights a lot lower consumption. A TV probably uses around 2-5A when running, a laptop on average probably about the same (possibly a bit more when the battery is recharging).
Running the air conditioning from solar power in an RV is generally impractical, certainly without having a very large solar and battery setup and perhaps a small air conditioner to boot. A typical RV air conditioner would require somewhere on the order of 100+ amps from the battery bank when running, and they are usually run for extended lengths of time. If you need air conditioning, you need either a shore power connection or a generator.
Microwaves (and other heating appliances, like coffee makers or hair dryers) also use a large amount of power, but limited use may be possible as they often are not used for extended periods of time. You would need a good sized inverter to be able to do that, and a reasonably large battery bank preferably.
The other side of the equation from electric usage is how much power you get from solar. I'm not really an expert here, but I've seen claims from people who are more knowledgable than I here that, as a rule of thumb, you can reasonably expect to get the equivalent of four hours worth of full output per day under good conditions--clear skies, not too far north latitudes, open areas. That would mean maybe 80-90 Ah or so going into the battery. If you're in a shady spot, that could very well be dramatically lower...probably enough to keep up with the fridge, I would guess, but maybe not much else.
You would be very well served to get some decent instrumentation to see how your electric usage and solar charging are fairing. At a minimum, I'd suggest a decent voltmeter and ammeter--and the ammeter ought to read both positive and negative current. The voltmeter gives some idea as to the state of your battery (though it's not the best way to do that), and the ammeter shows how much current is being put in or taken out at the moment. Better, and preferred, is a battery monitor such as a Trimetric unit, which monitors voltage and current constantly and figures out the state of charge of the battery from them.
For RVs, 12V electric usage is commonly computed in amp-hours (Ah), an amount of charge transferred by one ampere over the course of one hour. (It's not really a measure of energy per se, but since the voltage is taken to be more or less constant at 12V it is equivalent in practice). An absorption fridge might use an average of 1A when it's running, or 24 Ah per day; some use a good bit less, and probably some more, particularly if they have fans that must run for them to operate. Miscellaneous constant loads like the LP detector and CO detector might use a few Ah per day. Most other things are somewhat under your control--you can decide when and how much to use them.
Incandescent lights are an amp or two per bulb; LED lights a lot lower consumption. A TV probably uses around 2-5A when running, a laptop on average probably about the same (possibly a bit more when the battery is recharging).
Running the air conditioning from solar power in an RV is generally impractical, certainly without having a very large solar and battery setup and perhaps a small air conditioner to boot. A typical RV air conditioner would require somewhere on the order of 100+ amps from the battery bank when running, and they are usually run for extended lengths of time. If you need air conditioning, you need either a shore power connection or a generator.
Microwaves (and other heating appliances, like coffee makers or hair dryers) also use a large amount of power, but limited use may be possible as they often are not used for extended periods of time. You would need a good sized inverter to be able to do that, and a reasonably large battery bank preferably.
The other side of the equation from electric usage is how much power you get from solar. I'm not really an expert here, but I've seen claims from people who are more knowledgable than I here that, as a rule of thumb, you can reasonably expect to get the equivalent of four hours worth of full output per day under good conditions--clear skies, not too far north latitudes, open areas. That would mean maybe 80-90 Ah or so going into the battery. If you're in a shady spot, that could very well be dramatically lower...probably enough to keep up with the fridge, I would guess, but maybe not much else.
You would be very well served to get some decent instrumentation to see how your electric usage and solar charging are fairing. At a minimum, I'd suggest a decent voltmeter and ammeter--and the ammeter ought to read both positive and negative current. The voltmeter gives some idea as to the state of your battery (though it's not the best way to do that), and the ammeter shows how much current is being put in or taken out at the moment. Better, and preferred, is a battery monitor such as a Trimetric unit, which monitors voltage and current constantly and figures out the state of charge of the battery from them.
