INVERTERS? How much can I run for several hours on an inverter and what size is needed to run a laptop, a few cahrging ports for power tools and a mico? None of it in continuous use except the laptop at night? I was thinking 1000 watts pure sine?
TURN ME OVER
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ALSO - What rooftoop AC units can you reccomend? (3500 ext Transit)
Are you going to be adding house batteries to run your "load" off of? (Answer should be yes). Are you going to run your rooftop A/C off of a generator? (answer should be yes) We can go from there once you answer.
OK P&S39 - Yes on the generator for the AC (Also will welcome input on the Generator - Most often mentioned in this forum is Honda), as for the first part of your reply, what do you mean by "house batteries"? Go easy on me, I am posting on the Newbies Forum. I was assuming that I can run the inverter when idle for a few minutes to nuke something, then use my laptop for a couple hours?? The truck comes with dual HD batteries?? BUT< please feel free to school me. Thanks.
House batteries are those batteries whose sole purpose is to power your toys. The truck batteries are for starting the truck only.
Some dude named Ken Something or another has s great blog about this subject. Perhaps he might chime in with advise.
Here's one of Ken's blogs http://expeditenow.com/mobile/truckingblogs/390-how-to-kill-your-batteries.html
The first thing you need to become intimate with is Amps x Volts = Watts. It affects everything you do, every decision you make on what size inverter you need and on what capacity your batteries need to be. A 1000 Watt inverter means you can run up to 1000 Watts of regular 120 volt household appliances, because the inverter will supply 1000 Watts of power. This can be a single 1000 Watt appliance, or several small appliances at one time adding up to a total of 1000 Watts.
Also know that Watts divided by Volts will give you the Amp draw. A 1000 Watts appliance divided by 120 Volts is 8.33 Amps.
Next be aware that you'll need to know the amp draw (input power) of every appliance. Every appliance should have that information on it, either printed directly on it, or on a sticker, or even stamped into a metal plate. The information will either be in amps or in Watts. It will say something like input voltage 120v and then either amps or Watts.
It's important to read the actual label and not marketing information printed on the box. For example, a 700 Watt microwave oven does not draw 700 Watts of power, but rather gives you 700 Watts of cooking power. More likely, the input power will be 1050 Watts. And a 1050 Watts appliance will draw 1050W / 120v = 8.75 Amps.
A lower wattage microwave, like 700 or 900 watts of cooking power, will use fewer amps than a 1200 watt microwave, but the lower cooking power means you'll have to run the microwave for a longer period of time. For example, a 900 Watt cooking power microwave might draw 1200 Watts of power (10 amps) but might need to be running twice as long as a 1200 Watt cooking power oven that draws 1440 Watts (12 amps).
A couple of amps might not seem like much, but when you go from 120 volts to 12 volts, you're using 10 times as many amps for the same wattage. So 10 amps at 120 volts becomes 100 amps at 12 volts, and 12 amps becomes 120 amps. (and that's not even taking into account the 10% that's lost in the inverter during the conversion process, so 120 amps from the batteries actually becomes 132 amps)
When you look at all your 120 volt appliances and see how many amps they draw, 2 amps, 3.5 amps, whatever, when you run them off an inverter you need to multiply those amps by 10 to get how many amps they'll draw from the batteries. Amps x Volts = Watts. And Watts divided by the Volts equals the Amps.
12.5 Amps x 120 V = 1500 Watts
1500 Watts / 120 V = 12.5 Amps.
1500 Watts / 12 V = 125 Amps
I cannot stress that enough. Know the actual amp draw. People look at the amp number on an appliance and forget to multiply by 10 when running off an inverter. Or, they get confused, as can easily happen with a laptop's power supply cable when it says it outputs 4.74 amps at 19 volts. Since we know the above formula, you can go 4.73 Amps x 19 V = 90 Watts. And 90 Watts divided by 12 volts means it'll draw 7.5 amps from the batteries. Most laptop power supplies are 75, 90 or 120 Watts. Mine is 75 Watts, so it only draws 6.25 amps when charging. I can replace it with a 120 Watt supply, but that will draw 10 amps from the batteries through an inverter. Takes longer to fully recharge at 6.25 amps, but the lower draw is gentler on the house battery bank.
So, you question of how much you can run for several hours depends on the total wattage of the running appliances hooked up to the inverter, and the question of what size inverter is needed depends on the same thing. Chances are, a 1500 Watt inverter will be required if you want to run a microwave oven.
As for how long you can run those appliances, that all depends on the total amp draw of the appliances and the amp hour capacity of your batteries.
As other have noted, the batteries that came with the truck are designed for the truck - primarily handling the electrical needs of the truck to start it and keep the normal accessories running. They can handle small inverter loads, the kind that normal people use on a daily basis, like a GPS unit, charging a smartphone, even adding a small stereo amplifier to the truck. But they aren't designed for abnormal people and the abnormal uses we can find for them, Use the right tool for the job. You want to start the truck, use a starting battery. You want to run household appliances, use a house battery that's designed for deep cycle use.
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Before the OP runs out to buy a house battery, he needs to know: Make sure it has the same chemistry as the starting battery. I.e., lead-acid or AGM. Mixing chemistries will shorten the life of the AGM battery significantly, because the alternator will produce the juice needed to charge the lead-acid battery and leave the AGM one chronically undercharged.
Dear Mr. Turtle - Thank you, this is proof that I should have stayed awake in my Science classes! However, I get it and can use it to determine what my needs are. While Mr. Ragman explained what a House Battery is I still have a void in knowledge that needs filling. Truck batteries are for trucks and house batteries are for use with an inverter to produce "minor" power needs, BUT, what keeps the house batteries charged??
DOUBLE WOW! OK I will need to read thru several times to even know what questions follow, BUT, it is seriously good information
Being connected to the alternator thru an isolator.
At this point, however, I shall defer to Turtle's expertise in answering your questions. He is the wizard of wattage here; I'm just a thirsty beggar telling another thirsty beggar where some water is...
NOW - Let's bring back an older question. When it comes to power, recharging, heat, cold, etc., one of the questions is how long you can idle your truck engine. So, any info as to how this time frame relates to GAS vs. Deisel??
AH! Thank You, it's the isolator that closes the loop for me.
PLEASE, PLEASE - EVERBODY, keep providing you knowledge/opinion. After all, think about it, how often does someone ask for you opinion?? If your married we both know the answer to that!!!
The less you idle the better. The goal although hard to reach is 0 idle time. Your van will thank you.
A smartass Zen Master would say until the tank runs dry. All things being equal, I'd give the edge to the diesel.
Xiggi would say: "The less you idle the better. The goal although hard to reach is 0 idle time. Your van will thank you."
You should take Xiggi's advice!
There is another option, a 12V to 12V DC charger. A good one will cost more than an isolator. The charger is powered by the starting battery. A quality charger will provide 3 stage charging to your auxiliary batteries and act as an isolator. It will also have settings for the type of batteries to be charged so the starting battery can be different from the auxiliary batteries. I believe the Ford Transit comes with an AGM starting battery, being that it is located in the cab, under the driver's seat.
Forgive my ignorance on this but when I look up the part number on my transit battery it shows as Motorcraft. Are they a AGM manufactured battery branded that way?
I can say I love my set up. I've been sitting since 7am yesterday. Have a fantastic fan and a road pro fan running continually, was able to watch all the hockey games last night. Have 3 led ceiling lights running right now along with fans and run my cpap machine all night. Have AGM battery bank and 1,000 watt pure sine inverter. Haven't started my truck since I've been here. Bank charger when truck running. Isolated between starter and bank. I hope my starting battery is AGM so I'm not under charging house, but if it is not the next will be.