Power Inverter Location

[Doug J]

I'd like to get safety tips regarding the installed location of an 1800 watt inverter.
I installed one right next to a 12 volt deep cycle battery, inside a closed compartment. Later I read it might not be best practice to have the inverter in the same compartment as the battery.
Is there danger of explosion? Is corrosion an issue?
I'd like to know if others have their inverter installed in the battery compartment - any issues?

I like the inverter where I have it installed, good utilization of space. But I will move it, if it's recommended.

Bottom line - Is it safe?

 

[Benny17441]

It is low risk but still not safe and not the best location for inverter performance and longevity. There are heat dissipation and corrosion issues in the battery compartment and a fouled battery can emit a high volume of gases which in an enclosed space could become explosive . The inverter should be installed as close to the battery(s) as possible but in a well ventilated and dry location. "As close as possible" does not necessarily mean right next to it; an adjacent compartment would do fine and compensate for round trip wire length distance with the proper gauge of wire. Find a location outside the battery compartment and drill a hole to pass the wiring to the chosen ventilated location. Don't forget to place a fuse in the (+) wire of the circuit.

 

[Doug J]

Benny,
Thanks for your reply. Let me ask you this. Would the same apply to a 10 amp battery charger? I could swap locations between the two pieces of equipment. I'm just trying to keep those items hidden behind a bulkhead that runs across the entire aft section of my boat.

 

[Benny17441]

Doug, that would depend on what kind of charger you do have. I have seen some 10A marine chargers which are sealed, waterproof and contain no moving parts which would be safe to use near a battery in an enclosed space but there are others that are not that well protected. The same thing happens with inverters as there is a wide range in quality, features and prices. I had answered your question in general terms perhaps considering the worst case scenario of a low end inverter with little safety protection. I reaffirm that the risk for circumstances to come together for an explosion is low, the threat of corrosion damage is perhaps a little higher. In general a battery charger would be less prone to cause a spark than an inverter. You may want to verify which of the two units is better protected before making the final decision to swap them. What would be really good is to improve air circulation between that compartment and the outside. Opening up a couple vents to improve air flow might make that low risk more acceptable. Keep all connections tight and inspect them frequently. A fuse for the inverter is a must.

 

[Doug J]

Thanks Benny! Your response has helped a lot. I will consider my options after taking a close look at the battery charger, and make appropriate changes.

 

[Regular Guy]

View attachment 119783 View attachment 119786
Doug,
you might consider a location, close as possible to the battery for charger and inverter by avoiding (even if small) danger of corrosion and explosion by installation of the devices on the berth back wall on the cabin side.
Please consider that a 1,800 Watt inverter would draw 150 Amp by full load out of your battery! I decided to forget to use a hairdryer or electric heater if not on shore power and went with a max 800 Watt inverter. I use only 500 Watt (42 Amp), it runs my coffee maker and blender but when in use, I am carefully watching the state of the batteries.

 

[Maine Sail]

I'd like to get safety tips regarding the installed location of an 1800 watt inverter.
I installed one right next to a 12 volt deep cycle battery, inside a closed compartment. Later I read it might not be best practice to have the inverter in the same compartment as the battery.
Is there danger of explosion? Is corrosion an issue?
I'd like to know if others have their inverter installed in the battery compartment - any issues?

I like the inverter where I have it installed, good utilization of space. But I will move it, if it's recommended.

Bottom line - Is it safe?

As Benny said not the best idea especially if it is not ignition protected.

The biggest issue to be careful of with inverters on boats is making sure they meet the minimum safety requirements and most do not.

ABYC A-31
31.5.3.2 All marine power inverters shall meet the applicable requirements of UL 458, Power Converters/Inverters and Power Converter/Inverter Systems for Land Vehicles and Marine Crafts, and Supplement SA, Marine Power Converters/Inverters and Power Converter/Inverter Systems.

 

[Maine Sail]

Please consider that a 1,800 Watt inverter would draw 150 Amp by full load out of your battery!

At full load the battery voltage will usually be much lower than 12V so it is safer to figure on about 11V. We then can't forget about the inverters inefficiency which is stacked in there too.

1800W / 11V = 164A X 1.15 (efficiency) = 188A DC to power 1800W AC

You won't normally be using it at full output but the load to the batteries is still much higher than most often assume it is. For every amp of AC a safe figure to use is 1A AC = 12.5A DC..

 

[Doug J]

Thanks gents! A lot of good information. The 1800 watt inverter came with the boat, along with the 10 amp battery charger. I figure I likely will not use the inverter much, but it will be nice to have if needed. I may someday add a solar panel and it would be nice for the times I'm on the hook for a couple nights, could maybe watch a DVD.

Both the charger and inverter were mounted on the front of the aft bulkhead. The installations I have to say was quite sloppy. I just couldn't leave it like that. I'm in the process of re-doing just about all the installs done by the PO. I removed the bulkhead which has several holes and cutouts on the edges to allow wires and hoses to pass thru. Basically it was quite a mess. I plan to replace the bulkhead with a nice sheet of Birch or Oak. I really would prefer to hide everything in that compartment for a nice clean look.

I figure at this point I will swap positions between the charger and inverter, so the charger will be next to the battery instead of the inverter. On the rare occasion I use the inverter, I will open the compartment door for ventilation. In addition, I will install vents for general better air flow. My plan is to replace the deep cycle battery I have with two 6 volt golf cart batteries.

 

[Gunni]

On a small boat with limited battery storage it makes sense to avoid the use of inefficient electrical conversion through an inverter. Heck it even makes sense on a big boat. I took mine out and gave it away. It had an idle parasitic load that was easy to forget about as it drained the batts. You can do everything you need to do electrically with 12VDC while reducing your Ah consumption.