Power inverters and the 12v [Archive] - Honda Element Owners Club Forum

: Power inverters and the 12v


Greygoose
11-17-2010, 05:54 AM
I'm looking to run 2 electrical devices (not at the same time) from the 12v socket that comes standard on the E. I'm not sure if i should get power inverter or not to do the job. heres the two jobs:
1. run a crock pot for 3 hours during tailgating
2. fill up air mattresses when camping

the crock pot says its 265 watts. the air pump says 215 watts (but i've heard it can take 3 times that at initial start).

what size power inverter should i purchase for these 2 jobs?

will i need one to connect directly to the battery, or will the E's 12 v do the job?

how long can i run the device off the battery without risking a dead battery?

thanx

GreyGoose

CoffeeDragon
11-17-2010, 11:00 AM
You'll want an inverter that's rated for at least 50% more than the stuff you're gonna plug into it. In your case, a 500W or 550W inverter should do the trick. You want to make sure you buy one that's rated for 500W sustained, not 500W peak since the peak rating is only intended for 60-90 seconds at most. 500W units are very common so you shouldn't have any problems finding one. The bigger the better obviously, let your budget be your guide and buy as big as you can, you never know what else you'll want to use it for.

You should be fine plugging into the outlet for this kind of draw. The easy way to know if you need to hook directly to the battery is whether or not the unit you've purchased requires you to :-) Manufacturers are interested in having their product perform well so they won't sell a 3000W inverter that plugs into your power outlet in the dash.

As for how long the battery will last? Well certainly long enough to inflate an air mattress. Three hours of running a crock pot though might be asking a bit much. Most tailgaters (search the forums, there's a TON of them) opt instead for a very small generator (Honda, of course!) since you might start off with just a crock pot but once you've got 120VAC in the parking lot, there's going to be a world of other things you'll want to plug in. TV's, radios, chargers, pinball machines (no joke, I've seen 'em), the list goes on and on. Generators aren't as cheap as inverters but you're buying a lot more.

ramblerdan
11-17-2010, 11:08 AM
If you use a 12VDC air pump, it should use less power than an equivalent 110V pump due to losses though the inverter.

paulj
11-17-2010, 11:09 AM
What is the current rating on the 12v socket circuit of the E? 10 amp, 15? 12v*10amp=120w. 15amp=180w

ramblerdan
11-17-2010, 11:27 AM
Front and back are both 15A.

Bowzer
11-17-2010, 02:12 PM
FWIW, I've always planned to put in a more sizeable Inverter straight off the battery (Fused and protected of course) and mount in the rear. Then, run wiring for several AC plugs installed in key areas in the cabin. That way I can just plug and go with these AC powered items.

desinia
11-17-2010, 02:44 PM
Front and back are both 15A.

Front and back on mine came from the factory with 10 amp fuses which we found out the hard way when I wanted to use a 12 volt hair drier to thaw out mirrors and the like in the winter. Is anyone familiar enough with the wiring to know if I can safely use a 20 amp in either one of them? I know a simple 250 watt heater will blow out either socket.

Greygoose
11-17-2010, 11:05 PM
thanx everyone for you responses. i think i got the answers that i needed.

bottom line: This E aint meant to power anything more that a cell phone or laptop without hooking something up to the battery. Even doing so, its not recommended to run something without the vehicle running for more than about 30 minutes tops without potentially causing a battery issue. Its not theoretically what i wanted to hear, but i like reality much better than theory when it comes to real world usage of the unit. I'll have to change my tailgaiting ways and switch to a propane camping stove (vs. a crock pot) and buy a 600 watt inverter to do quick fill ups of inflatable type devices.

Sad but true.

thanx again for the reality check..

GreyGoose

desinia
11-18-2010, 02:26 AM
thanx everyone for you responses. i think i got the answers that i needed.

bottom line: This E aint meant to power anything more that a cell phone or laptop without hooking something up to the battery. Even doing so, its not recommended to run something without the vehicle running for more than about 30 minutes tops without potentially causing a battery issue. Its not theoretically what i wanted to hear, but i like reality much better than theory when it comes to real world usage of the unit. I'll have to change my tailgaiting ways and switch to a propane camping stove (vs. a crock pot) and buy a 600 watt inverter to do quick fill ups of inflatable type devices.

Sad but true.

thanx again for the reality check..

GreyGoose

Or, much less expensive, just get yourself a 12 volt inflator. I found a nice one at Wally World last year that does the tires or air mattress quickly, auto shut-off for the right tire pressure AND it runs on just under 10 amps. They don't seem to sell the same one online but this is probably the closest example: http://www.walmart.com/ip/Campbell-Hausfeld-12-Volt-Tire-and-Raft-Inflator-With-Light/15135634

OR, you can go with a cheapo 12 volt inflator usually sold in the aisle with the air mattresses. It won't do the tires but it will blow up inflatables very fast. Unless you're blowing up a Zodiac or the like, it'd be the no-brainer choice. http://www.walmart.com/ip/Coleman-12V-QuickPump-Air-Pump/9870593

Of course, if you ARE pumping up a Zodiac... http://www.walmart.com/ip/Airhead-12-Volt-Hi-Pressure-Air-Pump-With-Pressure-Release-AHP-12HP/5543947

ANY of these would be more economical and less hassle to hook up.

paulj
11-18-2010, 11:54 AM
I like to use a separate 12v battery pack when inflating an air mattress in the tent. That way I don't have to carry the inflated mattress outside, and risk brushing it against sharp tree limbs.
http://www.walmart.com/catalog/product.do?product_id=13005739

McGar
11-18-2010, 12:05 PM
I found a 12 v crockpot!

http://www.12volt-travel.com/12-volt-appliances-c-88.html

Greygoose
11-18-2010, 10:16 PM
I like the idea of a 12 v inflator, but i've heard that you cant run those units for more than about 5 minutes before they need to cool down. I may need something to inflate 2 kayaks with. which may take half the day with something like that. How long does it take you to fill an air mattress with this unit?.

Maybe someone can set me straight on this particular crock pot point. that 12v crock pot you mentioned is 1.5 quarts. what the heck is the rest of the crowd going to eat? if my crock pot is rated at 265 watts, and my stereo in my E is rated at 275 watts, its hard for me to believe that my battery would suffer any damage by powering this crock pot for 4 hours through an inverter hooked to my battery. I cant imagine my battery not being able to power my radio for 4 hours without running the engine. whats the difference here? if i plug a 600 watt inverter onto the battery, and run a 265 watt device through it, shouldnt i damn near be able to run this thing for 6 hours plus without having much effect on the battery? I guess i'm trying to figure out how much difference there really could be between a crock pot that runs at 265 watts and one that runs a bit under 180 watts (since thats what a 12v crock pot would have to run at to be hooked into the e's cigarette lighter). The gold standard would be for me run my crock pot through the inverter, while listening to the game on the stereo (therefore eating up about 550 watts).

This thread is really starting to get interesting. i appreciate everyones ideas and thoughts.

GreyGoose

desinia
11-19-2010, 03:11 AM
I like the idea of a 12 v inflator, but i've heard that you cant run those units for more than about 5 minutes before they need to cool down. I may need something to inflate 2 kayaks with. which may take half the day with something like that. How long does it take you to fill an air mattress with this unit?.
GreyGoose

You might be more interested in the "Zodiac" inflator I linked to. You can figure on about 100 gallons of air per minute output which I'm making a very uneducated guess would mean about 2 minutes or less to completely fill your kayak. The only pain is that you need to raise the hood and connect direct to the battery AND leave the engine running for that long. (Draws about 30 amps).

Pretty much ALL 12 volt heated appliances are very low power compared to the household versions because you're dealing with 12 volts now instead of 120 volts, which means you need to increase the amperage 10X to get the same amount of power. If you run a household appliance on an inverter, all you're doing is putting the inverter between the battery and the appliance - end result is that you're still using the same amount of amps from the battery plus the power lost running it through the inverter.

12 volt Crock pots are smaller, coffee makers make coffee slower (if at all), pizza ovens only make big cookies or take -forever- to get anything done, etc. This is why campers generally tend towards cooking over flames, unless you're parked in a spot that provides electrical power.

And because you mentioned it, my oem Honda battery certainly wouldn't have been able to run "just the radio" for 4 hours without needing a jump start afterwards.

breese524
11-19-2010, 09:30 AM
And because you mentioned it, my oem Honda battery certainly wouldn't have been able to run "just the radio" for 4 hours without needing a jump start afterwards.

I will tell you from experience (stuck at a turnpike rest stop on Christmas Eve) that you cannot run the radio for just 1 hour without needing a jump to get started. That battery really is just a starter battery.

Erik F
11-24-2010, 11:05 AM
I had the same problem listening to the radio...killed the battery dead. Inverters are only rated to 150 watts when drawing off the 12v plug...if you want anything larger you have to run directly off the battery. I just bought another 400watt inverter off of NewEgg.com for 19.99...I'm a little unhappy with it since it runs the little fan inside it all the time...a little loud...I have a 180watt that uses no fan at all. Does anyone know of a bigger better battery that will fit were the current 9v Duracell goes?

MotoChef
11-24-2010, 10:46 PM
I was looking at a 2000 watt inverter for running a refrigerator for a trailer and the open a Freight Harbor Tool store by me and they have some cool options!

http://www.harborfreight.com/catalogsearch/result?category=&q=power+inverter

Dom.five
11-25-2010, 10:18 AM
I have used a 400W inverter to run the crockpot on several occasions. I just make sure it is up to temperature before plugging it into the E. It has worked flawlessly for several hours. We kept things cooking on the way to Carly's house for lights in the park, last year. ( While running the Engine) Do not try to use it with the engine off!

Other than that, the DC pump is the way to go. Forget the AC air pump.

Dom