Might need to rethink this. I went with the 1000w because the 2000w was out of stock, and i convinced myself it would be a good value because down the road you could use the 1000w for a compressor fridge upgrade.
Inverter/charger sounds interesting. Especially for someone like me and lots of others who have the WFCO converter. Fairly certain it does not kick into 14.4v ever. Ive tested it years ago but forget. With the battery switch disconnected, the silly thing goes into 14.4v mode on its own about every 2 days. Might be something like every 50 hours because the time changes enough that i sometimes catch it and sometimes dont. I just try to turn down lights and fans on hot days when it kicks into unneeded high voltage. Its not even hooked to the batteries. Other day i noticed it was at 14.4v. Turned the battery switch to on. Went out there and it was putting about 3amps into the battery. Held 14.4 for a bit. So i guess i lied.......there has been a time my WFCO charger sent 14.4 down to my batteries. Really they want higher voltage than 14.4 especially with winter coming. I have solar but its only 150w currently. I do supplemental charging using an RC car charger a handful of times a year to equalize them. (or a funny trick....i put the 5a battery tender on the single 6v if im being extra lazy...never gets to 8v though on my healthy batteries....older batteries might climb so its critical to monitor)
Being able to fast charge a pair of 6v sounds real nice. Its what flooded batteries prefer in terms of longevity. Thats another reason i didnt go with 2000w is because ive read the 6v sag under load compared to lithium. So i wasnt even going to try pulling off the microwave using batteries. I was also wondering about efficiency of a 400w at a 50w load compared to a 2000w at 50w load. I asked once on an RV forum. They had actual data to share. The 2000w was not as bad as i expected. In terms of efficiency. For example i read above Cookie just scored a 3000w. If he is only charging a laptop....that wont be wasting a lot of battery power right?
The 1000w posted above has an ECO mode. The instructions have broken english so its hard to get an idea of what it means. I think if you have ECO mode activated, the inverter will not power on until the current draw is over 50w. Which i hope is not true. At first i hoped it meant that if you are drawing under 50w of current, the inverter will do things to be slightly more efficient and save your battery power.
I might be more help if I knew what batteries you have and what you want to accomplish in terms of loads running off of the batteries. As for the eco mode, if you're running your fridge all of the time, that's more than enough to keep it powered up.
For example, this latest customer wanted to run everything except his 3 A/Cs off of the inverter, so I told him to get the 3000w inverter/charger and 400 ah of Lifepo4 to handle the micro and whatever power he uses overnight for stereo, lights, furnace, etc. He also has massage couches, so that's a bit of a load as well.
A lot of people throw a bunch of batteries at it or tons of solar and it's not really a balanced, integrated system because they spent all of that money and all they can do for $10,000 is run the micro, the same as my customer is doing for less than 1/3 the cost.
I'm no longer recommending 6v batteries to anyone, since LiFePo4 batteries are so cheap and so much better. For example, LFP are about 99% efficient, FLA loses 20% during charging and about 20% during discharge at recommended loads, at higher loads the discharge losses are even worse. FLA batteries also need constant watering, weigh a lot more, take up more space and die within 4 yrs at best, plus they self discharge at about 10% per month if left without a trickle charge. LFP self discharges at about 1%/mo. and doesn't need a trickle charge.
4 x 6v GC batteries gives one about 440Ah, at 50% usable, that's 220 Ah for a cost of about $400 from Sam's club or about $600 for Trojans. A 200 Ah LFP from Amazon is only $700, lasts 15 -25 yrs (depending on how often you use the trailer), has 160 Ah usable at 80% depth of discharge, weighs about 46 lbs as opposed to 252 lbs for GC batteries. 2 of those 200Ah batteries gives 320Ah usable which is roughly equivalent to 6 GC batteries, if you ignore the 40% losses during charging/discharge. LFP also don't sag anywhere near as much as FLA, plus they deliver all of the advertised power even at high current draw, FLAs deliver less power as the current increases.
