Inverter install 2011

[Garth]

I just bought a Go Power 1500 watt inverter and was wondering if anyone here has installed one and had some pointers....thanks, Garth

[BoarderM]

Haven't installed one but I just read an article in "The Family Handyman" about installing a power inverter. I just checked their site and the article is there.How to Turn Your Truck Into a Generator | The Family Handyman

[Bassman]

I have not installed an inverter or used one that large in any automotive application for one main reason; they are very inefficient and draw a tremendous amount of power. Only about 60 - 65 percent efficient under the best circumstances, a 1500 watt inverter will consume about 2300 watts to give the full rated 1500 watt output (65 percent efficiency). At 12.6 volts, this equates to just under 185 amps current draw.

With this much current, you will either have to use a second, dedicated battery with an isolator (to prevent draining the main battery) or have the engine running while you are using it. Additionally, you'll need power supply wiring the size of battery cables to properly power the inverter.

I hope this information was helpful.

[Looby]

Originally Posted by Bassman

At 12.6 volts, this equates to just under 185 amps current draw.

FWIW, the OB 2.5i alternator is rated at 130 amps, so it's prolly
not a good idea to run that 1500 watt hair dryer for too long.

Looby

[Bassman]

Originally Posted by Looby

FWIW, the OB 2.5i alternator is rated at 130 amps, so it's prolly
not a good idea to run that 1500 watt hair dryer for too long.

Looby

Good point, Looby - - thanks!

[lockmedic]

I've installed several in my locksmith trucks. First question before getting into a lengthy discussion about how to hook it up: what do you intend to use it for? Will you want to use 120VAC stuff with the engine off? If so, what do you want to power and for how long (amperage of the device(s) would be helpful)?

I've put them in from simple 1200 watt mounted under the seat hooked up to the battery via a constant duty solenoid that was energized with the ignition (so the inverter would never run while the engine wasn't running) with no home battery to a Tripp Lite 2000 watt inverter/charger with shore power connection hooked to a 2200 AH array of golf cart batteries that will run all my equipment, laptop, flourescent lights, and I've welded with it in a pinch (120v MIG).

[Garth]

Boarder thanks!

That was very helpful! I think that is just what I am going to do. Use a 2nd battery with an isolator. Garth

[lockmedic]

Isolators are tricky to install as they require interrupting and splitting (via the isolator) the wire from the alternator to the main battery. Your alternator may also need to have the exciter circuit allowed for as i doubt it's a self-exciting alternator.

A much easier way to do it is to use a constant duty solenoid to simply switch a charging wire to your aux battery with the ignition. It does have the potential to allow both batteries to discharge to the inverter IF you're drawing more power than the alt can provide WHILE the engine is running. . . and you probably won't be doing that.

2nd battery adds weight and potential caustic/explosive fumes that must be routed outside the car unless you're running a sealed unit (like an Optima).

[Garth]

I was thinking of hooking up the 2nd Battery to the Main one Via the Isolator. I was just wondering how well it would charge having to be fed from the Alt Via the main battery. I am thinking that if the main battery is fully charged all the charge will just route to the 2nd Battery. What do you think?

[lockmedic]

Let's make sure we're talking about the same thing. . . an Isolator is really nothing more than a big pair of diodes in a fancy block with some bolt lugs and a heatsink. All it does is act as a splitter/pair of one way valves to allow power to flow from the alt to each of the two batteries but NOT from one batt to the other. They're problematic to install as to do so properly it needs to go between the alternator and main battery. If you tether it to the main battery (instead of interrupting the alt wire) it WILL allow your main batt to discharge into your aux batt, which is exactly what you DON'T want it to do.

A much simpler solution is to use what I'm calling a constant-duty solenoid, but what the link above calls an "isolation relay" which accomplishes the same goal but in a different manner and doesn't require interrupting the main feed from the alternator. A constant duty solenoid is basically just a heavy-duty magnetically-operated switch, essentially the same thing as a starter solenoid except rated for continuous use. With this arrangement, you do connect your main batt to your aux batt via the solenoid. You connect the trigger (coil) on the solenoid to an ignition source so the solenoid only closes the circuit between the batteries when the ignition is on, allowing the alt to charge both batteries, and either batt can hypothetically discharge into the other but that's unlikely as the alt (if healthy) should be putting out more voltage than either and thus charging them. When the ignition is off, the circuit between the two batteries is broken and thus each batt can only be discharged by whatever is wired to it. . like the dome lamp on the main batt, or the inverter on the aux batt. One nice side effect of using a solenoid is you can wire it up to combine the batteries on demand if desired, provided your solenoid is large enough for the task of say, starting the car. . . which is a common scenario where that would be useful (using your aux battery to self-jump-start your main batt without cables).

You can buy them from most RV supply places for less than $30. Napa also carries them but expect to pay a bit more. They're used routinely for stuff like hydraulic pumps for liftgates, upfitters use them for wiring up RV/ambulance conversions, etc.

Using a solenoid or isolator won't effect how your secondary battery charges. . . that's entirely up to your alternator and batteries. The isolator or solenoid just prevents you from discharging your main battery while running your inverter.

Again, all of this is generic advice. What do you plan on running with it? You need to size your aux battery array according to what your energy requirements are, if known. If not, buy a battery and do the math to figure out what your run time for a given load will be. Hint: it will be significantly lower than your battery's reserve capacity by the time you figure in losses through the inverter plus the fact that you want to discharge the battery as shallow as possible.

If you just want to run something like a portable TV/fridge every once in a while, you'd be better off just keeping a deep cycle battery around on a trickle charger and throw it and the inverter in the back of your Suby with nice short leads, then throw it back on the charger when you get home. To properly wire up a second battery, isolation relay (constant duty solenoid), and inverter, plan on spending at least another $200-300 and at least a few hours work.

If you just wanna run something like a laptop charger, the sort that plugs into the cigarette lighter is generally adequate and a **** sight easier to install.