JenniferW
In my RV, somewhere
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I am a full time solo woman RVer and am trying to understand what I can do with regard to a more powerful inverter.
I have one 300 watt inverter that I connect to my batteries and use to power my laptop, charge my phone, etc., but would love to have something that can also power my coffee pot and maybe run the microwave.
Currently, I just fire up my generator to do so, but I am often in a place where I might not want to draw attention to the fact that I am 'camping' there. (Parking lots, etc.)
I have two really good 6 volt Interstate golf cart batteries.
If I bought a 2000 watt inverter and connected it to my batteries, can I use that to make coffee or even run my microwave?
Or would I deplete the batteries immediately?
Any guidance is always appreciated. It has been a huge learning curve since I started in March, and I'd postponed this brain busting electrical stuff for later!
Thanks,
Jennifer
Full time as of March 30th!
My Blog: www.livinginmycar.com
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bldrbuck
one or the other
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With 2 batteries you may be able to brew a pot of coffee but they will be almost fully discharged when it finishes. You may be able to run the microwave for 10 minutes with the same result. You are using 10 amps from the batteries at 12 volts for each watt of 120 that you use. You will need to run the generator several hours to recharge the batteries.
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JenniferW
In my RV, somewhere
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Thank you!
One more thing, I looked at my batteries, and they are each labeled
122min@75amps
232amp/hours
Not sure if that was critical info that I left out of my original post.
Thanks!
Jennifer
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Sailbad
Bernardo, New Mexico or Quartzsite
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JenniferW wrote:Thank you!
One more thing, I looked at my batteries, and they are each labeled
122min@75amps
232amp/hours
Not sure if that was critical info that I left out of my original post.
Thanks!
Jennifer
Hi Jennifer, I fulltime. I have a much larger battery bank and a direct wired 2000 watt inverter. I average about 120-140 amps a day.
That's with the TV running, lights and computer. I run the refer and water heater on propane. I make my coffee every morning and usually will run the microwave for a minute or so to warm up something.
So, I have a much larger draw than you do.
You have roughly 230 amps of batteries. Not discharging over 50% means you have roughly 100 amps to play with. That's plenty to make a pot of coffee, short microwave maybe a little TV.
Set your inverter at 12.2 cut out and you probably will have no problems.
Dave C.
2005 Silverado 2500 CC
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JenniferW
In my RV, somewhere
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Thanks so much. Maybe I will just get one and keep a voltmeter handy so I can get the feel for it.
I forgot I need to think of 50% of my battery capacity, and don't get to spend all of it.
One more question, if EACH 6 volt battery says 232 AmpHours, does that mean I have 464 AmpHours? The batteries are the new Interstate 6 volts (about $150 each).
This stuff scrambles my brain, so thanks for the help.
Jennifer
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smkettner
Southern California
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No just 232, you add voltage OR capacity, never both.
You can get a stovetop drip coffee maker, use a percolator or a french press what ever that is to make coffee quietly.
Microwave may work on just two batteries but will draw significant power. Mine draws 160 amps from my four batteries. Honestly unless you plan to add battery I would find a different method to heat or a product that can go on the stovetop.
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KendallP
Grants Pass, OR
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Yeah, unless you've got solar, you're going to need to run the generator anyway if you do more than a day of that kind of usage.
And FWIW... a percolator is the absolute worst form of coffee maker ever invented. But not everyone cares. Especially those that prefer a lot of creamer or mocha or all kinds of flavors. But if you like the taste of good coffee, use a french press on the road. That's what we do.
Another great option that we also do is those little, single cup filter dealies. It takes a LITTLE time, but it's not bad at all. And each cup is fresh that way. But if you're in a hurry, the french press takes abut as much time as a percolator or Mr. Coffee-type drip unit.
Cheers,
Kendall
1986 Winnebago Chieftain 22RC
Our Camper (with no payments)
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dmartin@newarts.com
Ames, IA
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You can safely run your inverter until the inverter refuses to operate - inverters have built-in low-voltage warning beeps and shut-offs that'll prevent your batteries from being discharged too far.
Your microwave might best be used on batteries for brief bursts (like re-heating coffee) but not for long time cooking. An electric coffeemaker on the other hand heats water for a long time, hence uses a lot of your battery's capacity.
A good strategy is to make coffee, cook, etc with fossil fuel & reserve battery use for only brief reheating bursts. Use only LED and fluorescent electrical lighting when on battery power.
If you run your engine or generator & inverter while you use 120V power the energy will not come from the batteries. Therefore, when you stop at a rest stop for a snack, just leave the engine running while you run the coffee maker or microwave.
A pound of fossil fuel holds about 300 times more energy than a pound of RV batteries, so use the fossil fuel whenever you can.
Dave
PS the basic engineering is simple. Batteries hold energy - your deep cycle batteries can provide maybe 1500 watt-hours through your inverter. Your electrical devices are rated in watts.
So your system can run:
a 1000 watt microwave for 1.5 hrs (1000w x 1.5hr = 1500w-hr)
a 100 watt light bulb for 15 hours (100w x 15hr = 1500w-hr)
a 1500 watt electric heater for 1 hour (1500w x 1hr =1500w-hr)
a 1 min (1/60 hr) microwave reheating of coffee 90 times (1000w x 90/60hr = 1500 w-hr)
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wa8yxm
Wherever I happen to park
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With 3 pair of golf car batteries (660 amp hours) you could upgrade to someting like a xantrex Prosine 2.0 (2,000 watts) or 3.0 (3,000)
Now, I will tell you I like true sine wave (They do not bother my radio, work just like shore power, in fact where as on the Xantrex X-POWER site there is a document with a title something like "Things that may not work on MSW inverters" on the Prosine site.. Well, here is the list "Anything needing more power than the inverter can supply" Kind of a short list.
Now.. since a 2.0 can suck nearly 200 amps you don't hook it up with clips. You hard wire it in.
30 amp breaker on your main AC panel feeds the Prosine
the prosine then feeds a SUB panel which feeds Televisons, Microwave and kitchen/bathroom outlets.
On the 12 volt side the inverter is mounted in the compartment NEXT TO the batteries with very heavy cables (go one size larger than XANTREX suggests bolted direct to the battery save for the one that goes via the Fuse "T" type, very heavy duty)
Works great
Nothin adds excitment like something that is none of your business
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pianotuna
Regina, SK, Canada
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Hi Jennifer,
Here is another way to think about watts @ 120 volts draw from the battery.
If there is a 100 watt light bulb it presents a load of about 10 amps to a 12 volt battery, by the time the inverter inefficiencies are taken into account.
So the conversion is watts divided by ten.
The twin golf cart batteries offer 232 amp-hours of storage, of which 50% is usable (or 116 amp-hours). They don't like to have a load larger than about 75 amps.
So if the coffee pot is 750 watts and takes ten minutes to brew a pot it may consume 75 amps / 1/6 of an hour = 12.6 amp-hours. If it takes 20 minutes it will use about 25 amp-hours, and etc.
On the other hand if a 2000 watt inverter were running "flat out" it may draw over 200 amps from the battery bank and use 50% of battery capacity up pronto.
In real life, there likely would be so much voltage drop that at 2000 watts the inverter would fault out from low voltage. You might be able to manage five minutes--if the batteries are really new and well charged. Or if they were AGM format they would run a lot longer.
Really a 750 watt inverter is about all two golf cart batteries can manage to power, other than for "brief" bursts of power (one minute to warm a cup of soup in the microwave, etc.)
Regards, Don
Kustom Koach Class C 28'5" 256 watts solar, 875 amp hours in two battery banks 12 volt batteries 2500 watt inverter.
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