2000 watt inverters (or inverter/chargers) are not small investments. Most would want to protect that investment so they can use it for as long as possible and still get the performance they need.
So - here are some thoughts:
Inverters hate to be too hot, but many are installed in engine
spaces where it is very hot. And, many are installed under berths or salon cushions
without adequate ventilation to help with the heat they generate. The harder they work the hotter they get. Sometimes you are limited in location but you can at least mitigate it by providing some ventilation under salon
seats, etc. In engine
rooms, it is hottest at the top but you may not be able to avoid that. You make your decision and you pay your price
Battery fumes are even worse for inverters than heat. The connections corrode, the internal metals corrode, the boards corrode. The manufacturers ALWAYS state - "Do not locate them above or too close to batteries". Having said that I did do that over my AGM
batteries. I would not have done that over wet cells. If you do, you will definitely have to replace the inverter quicker than you would if it were located elsewhere. Use longer, larger, cables to install it anywhere else than over the top of the wet batteries. You can cheap
out short term but I guarantee you will not long term. Warranties don't cover corrosion
and in any case will take longer than the warranty.
You can always mitigate the voltage drop from wiring
with larger wire. Some inverters are more sensitive to voltage drop than others but you should always follow the manufacturers recommendations and if in doubt go bigger. I used 2/0 for mine and it was very close to the batteries. It is a wiser investment to go larger wire to get the inverter to a cooler, better ventilated, and less corrosive place. This is not an area to go cheap
Lug sizes are a consideration, especially on the safety
ground, for some inverters. But I can't remember seeing a recent 2kw inverter that would not take 2/0 wire. If there is an issue with putting a big crimp on a post I would take my dikes or other cutter
and trim the lug done on the sides a bit. If it will not accept the wire into the screw down type insertion connection, you can carefully reduce some of the battery wire up to the insulation
. This is not my preference but better that than using too small a wire. Or, you can take a smaller wire off of the inverter and take it to a cable post and put the smaller cable from the inverter to a much bigger wire from the post to the batteries. This is perfectly workable but you do have two or four more crimps to do right and you have to make sure the posts are kept tight.
Also, make sure you install the safety
ground of the same size, or only one size down, from the main positive/negative cables. If the inverter has an internal failure the full current might have to flow through this wire. If it is too small it will overheat and possibly start a big electrical
Most voltage drop problems I have seen have been from running down the batteries and not from the wiring
(if the wiring was the right size in the first place). We would often run the inverter hard with a microwave, on boats with them, with a cup of water
if we needed to test the charging
function of the charger
or the alternator
. If the voltage of the batteries was too high, the charging
regulators or the inverter regulation would not kick in full charge mode. So we could test the alternator
quicker than waiting for a smaller load to bring down the batteries. Granted this was only done for 1-2 minutes with just a cup of water
in the MW. During regular use and you run the inverter for harder/longer, it will drop the voltage of small banks quickly and even larger deep cycle banks for really steady heavy use (like a hair dryer). The battery bank size is a big factor in how long you can run the inverter hard.
Last - welding cables are cheaper than marine
grade cables of the same size but are NOT recommended on boats - in general - especially in the engine room, bilge
spaces, or anywhere else they may get wet or oily or where they can get diesel
on them. Some welding cable may be rated for oil
and chemical resistance but the standard stuff is not. I have literally pulled out welding cable where the insulation
would be soft and pull off the cable by the dissolution of the cover by oil/diesel. Insulation failure is usually on the side of the cable that is down, or under, where it is difficult to see. No insulation can lead to fire and equipment
failure. My new(old) boat came with welding cable. I have inspected all of it and have a plan to replace it soon. It is a cost I don't really want since large marine grade cable is so expensive, but I will sleep better at night knowing my boat won't burn up either with me on it or not.
Also, if you do use welding cable you need to make sure its temperature rating is equivalent to the rating of the wire recommended by the manufacturer. If you take a look at battery wiring sizing tables there are multiple columns for different temperature ratings with the larger wire size (smaller gauge) required for lower rated cables. Welding cables are usually not rated as high as the good marine wire cables are so you need to go up in wire size.
This is not an area to go cheap.