Another Inverter Selection Question

JWA · 01-14-2018, 07:02 AM

I'm sure this has been discussed before but looking for what's most recent technology-wise and of course longevity with the different brands. My use will be limited to cordless tool battery chargers permanently installed in a work truck. There will be two of these one each for different types of batteries I use, Ni-Cd and Li-Io. These chargers are 120 VAC, electronic in nature but hardly complex or requiring any sort of sophisticated output, no true sine wave etc.

Maximum load the inverter would ever see is 3.0 amps 230 watts as measured with 120 VAC. I believe that would equate to about a 22 Amp DC load?

So the question is which brand, type and capacity would best suit those needs? It would never be tasked with anything different or additional loads. Its installation would be permanent and connected through an engine-running only relay directly to the battery through an existing 2 gauge wire, circuit breaker already inline.

Good quality is more important than price but would like to keep it "reasonable".

TIA

J W

1der · 01-14-2018, 10:27 AM

JW - 3A x 120 v = 360w
That would equate to 30A @ 12v, if perfect. (360/12)
Efficiencies in DC to AC conversion is about 85%, or can be less as you go down the inverter quality scale.

My two cents:
I purchased a smaller portable Samlex 450w inverter to use in our cars. It is amazing how much the fan runs on that when charging a laptop. I guess the heatsinks are not large enough to dissipate the heat. I was using it via the cig lighter, so that may have contributed to the heat build up.

Will you be plugging the van into shorepower on occasion? Will there be a van battery charger in the system? These may suggest finding a unit with the transfer switch and multi state charger integrated.

Due to the high cost of the tool batteries, I would still look for a true sine wave just to be safe, cleaner power. Around 1000 Watts, with good specs and well built. Decide on the transfer switch/charger needs, or if you want separate units for those functions, too.

arctictraveller · 01-14-2018, 10:44 AM

On the other hand, if it were me, I wouldn't over think this. The price for true sine wave inverters has dropped so low these days that I see no reason to save a few (very few) bucks with a modified version. There are plenty of 400W true sine wave inverters for under $50, (try Google) So, even if you bought one that only lasted a few years, your total investment will be so low you could afford to replace it with little pain. Having said that, the technology has advanced enough that most inverters are pretty reliable and should last many years. I have a 400W TSW installed in my van (it was in my boat before that, but I had to upgrade to a bigger one), and it's been subject to much physical abuse for several years in a marine environment and Baja too, and it never fails to work. I think, at the time I installed it I paid well under $200. Stick with a name brand and you should be fine.

ShuttlePilot · 01-14-2018, 10:58 AM

The 300 watt Morningstar Sure Sine is considered the bomb proof standard among my off grid friends for the smaller purpose inverter. These don't seem to get much attention as they are more expensive at around 250$ and not sexy looking. Cheap and sexy is often what grabs folks attention these days with solar stuff. The advantages of these is reliability (no fans, practically water and vibration proof) and very low consumption for the inverter it self.

Spec Sheet
https://2n1s7w3qw84d2ysnx3ia2bct-wpe...NG_R2_1_08.pdf

-Eric

JWA · 01-14-2018, 11:05 AM

Quote:

Originally Posted by 1der

Will you be plugging the van into shorepower on occasion? Will there be a van battery charger in the system? These may suggest finding a unit with the transfer switch and multi state charger integrated.

Due to the high cost of the tool batteries, I would still look for a true sine wave just to be safe, cleaner power. Around 1000 Watts, with good specs and well built. Decide on the transfer switch/charger needs, or if you want separate units for those functions, too.

Hey Ray---thanks for the reply!

This would be hard wired into the chassis wiring for a permanent installation. Most likely accessing it after the "new" van is finished would be somewhat difficult so having enough capacity to NOT trip an internal breaker would be optimal. I don't see this being called upon more than a few hours a week which I'd consider high usage in its anticipated role.

I usually charge my cordless tool batteries inside the house when needed, tend to keep more than I'd need in any one day always at the ready. Because I have enough batteries already shuttling back and forth between the truck and house is just pretty much SOP for me. (These are Milwaukee-brand batteries, all in nearly new condition electrically.)

There would never be any shore power connection, my preliminary design having the inverter receive chassis power only when engine is running. I can use a heavy duty relay (Blue Seas Product maybe?) for that. I'm strongly considering not allowing power to the inverter when in "accessory" mode. I don't really fear running the only vehicle battery down but better safe than sorry.

Quote:

Originally Posted by arctictraveller

On the other hand, if it were me, I wouldn't over think this. The price for true sine wave inverters has dropped so low these days that I see no reason to save a few (very few) bucks with a modified version. There are plenty of 400W true sine wave inverters for under $50, (try Google)..................... Stick with a name brand and you should be fine.

That makes sense and gives me a bit more to go on----any brands either of you would recommend?

Thanks again guys---I just knew someone here would be helpful with this.

JWA · 01-14-2018, 11:08 AM

Quote:

Originally Posted by ShuttlePilot

The 300 watt Morningstar Sure Sine is considered the bomb proof standard among my off grid friends for the smaller purpose inverter. These don't seem to get much attention as they are more expensive at around 250$ and not sexy looking. Cheap and sexy is often what grabs folks attention these days with solar stuff. The advantages of these is reliability (no fans, practically water and vibration proof) and very low consumption for the inverter it self.

Spec Sheet
https://2n1s7w3qw84d2ysnx3ia2bct-wpe...NG_R2_1_08.pdf

-Eric

Hey Eric---your reply came while I was replying above.

That $250 isn't out of range if its long lasting. If its indeed that stout it could be used in another application should the current one need to change.

Looking over Morningstar's site though it seems the 300 Watt is the only model offered----or did I miss something there?

Thanks!

Glider · 01-14-2018, 12:08 PM

JWA, a quick clarification question: There are different considerations when identifying an inverter that is going to be tied into a vehicle's power panel vs. a stand-alone installation, in which the equipment is plugged directly into the inverter.

It sounds like you are going the stand-alone route, and are NOT intending to use the inverter to power a breaker panel in your rig. Is this correct?

JWA · 01-14-2018, 03:04 PM

Quote:

Originally Posted by Glider

It sounds like you are going the stand-alone route, and are NOT intending to use the inverter to power a breaker panel in your rig. Is this correct?

You are correct ma'am!

The power feed to the eventual inverter is direct to the battery/alternator and is protected by an 80 amp breaker installed next to the only battery.

Glider · 01-14-2018, 03:14 PM

JWA, we are misunderstanding each other. I understand that the power IN to the inverter is direct from your battery/alternator. I am trying to ascertain what you are doing with the power OUT from the inverter.

Many inverters have power outlets directly built into the inverter. Other inverters are designed to be wired to a 110v circuit breaker panel. From there, the power is distributed to outlets built into the van. You would plug your load into those outlets.

There are different considerations for each of the two setups.

Option 1: Are you planning to plug your cordless tool battery chargers directly into an outlet that is built into your inverter?

Option 2: Are you planning to hard-wire your inverter into a 110v panel inside your van so you can plug your cordless tool battery chargers into outlets that are built into the van and fed by that panel?

JWA · 01-14-2018, 03:55 PM

Quote:

Originally Posted by Glider

JWA, we are misunderstanding each other. I understand that the power IN to the inverter is direct from your battery/alternator. I am trying to ascertain what you are doing with the power OUT from the inverter.

Option 1: Are you planning to plug your cordless tool battery chargers directly into an outlet that is built into your inverter?

Option 1 all the way. There would be nothing else ever plugged into this inverter.