I need advice on Inverter Purchase

[Vicr]

Do you guys actually mean a single pole double throw switch? 3 way switches are used to switch hallway lighting where there is a switch on both ends.

[craigav]

Originally Posted by Vicr

A 2500watt inverter (any inverter) runs about 80% efficiency 2500 x .8= 2000 watts. 2000w/120v= 16.66 amps.

Hi Vicr,

While it is true that all inverters and transformers have an efficiency rating measuring their power loss (my inverter claims >88% efficient on battery power) and it is also true that those made in China may not even be rating things honestly. However when the "output specs" state that it can put out 2500w continuous then the efficiency loss is not a reduction of that output rating, rather it is an increase in the input wattage. So for easy math, 3000 watts input with 2500 watts output = a 2500w continuous output rated inverter.

In any case, the heaviest load I run and likely most of us would run is the microwave ~1350 watts and I never run multiple heavy loads at the same time and certainly wouldn't recommend that. I would suggest to everyone to purchase an inverter with as close to twice (or more) the size as you intend to commonly use at maximum for as all inverters will last a lot longer running half its rated capacity vs running 100% of its rated capacity.

One caveat though, if I needed to run a low power device overnight such as a cpap, and I you wanted to use an inverter to do that, then I would have two inverters, a small one that is rated around 2~300w and then a larger one (2500w +) for overall RV usage at other times. As related to Vicr's point there is also power cost just with turning on an inverter, not to go deeper just keep in mind that a smaller inverter would be more efficient for lower wattage needs than using a large inverter for a very low wattage need.) ~CA

[Vicr]

Craig, what brand/model# inverter are you running? Most anything electronic/electrical the manufacturer fudges on the spec's especially when it comes to genset or inverter output. I've been in the electrical construction industry for 38 years and design and build electrical systems for a living. At some point I am going to upgrade my inverter and if I could get a pure sine wave inverter that ran at 88% I'd be a happy camper. I have a battery bank of (2) J-185's and (2) 31's with a reserve capacity of 1220 ah @ 25a so plenty of capacity for inverted power.

As far as looking at specifications in the electrical industry we rate to the lower of the standards to compensate for variables hence my 80% comment which is what I engineer to when factoring battery banks in data or telco centers. Always err on the side of caution.

[craigav]

Hi Vicr,

I have the Aims PICOGLF25W12V120AL Here is a link to the manual I was referencing. https://www.aimscorp.net/documents/P...V%20071218.pdf
It doesn't say in the manual made in china however that doesn't mean anything, and I don't have a lot of trust in things made in china. With that said, I think they are all made in china or at least with parts made in china.

I would read up on any inverter you plan to purchase, Aims has decent reviews but you can find youtube videos where people claim that if you try to run one at 100% capacity for an extended period of time they will overheat and burnout the transistors. Some people on youtube have modded the fans for this reason.

This one has several things I like that only the way more expensive ones have such as 30a internal transfer switch, 85a battery charge circuit, standby mode that takes very little power and monitors for any electrical load before turning on, and it is a low frequency inverter (LF) which has a heavy transformer in it which allows it (according to the specs, not tested by me) to output 7500w surge loads. Also, I am switching over to Lifepo4 and this one has a setting for charging lifepo4 batteries.

I wholeheartedly agree on erring on the side of caution, which is why I would recommend to everyone to purchase an inverter with much more rated capacity than you would ever intend to use at any given time (150%+). You may need even more overhead for the lighter weight type of inverters that use high frequency instead of one using a heavy transformer (LF) inverters as the lightweight ones cannot surge 300% like the LF inverters can. However lightweight HF inverters claim to have a higher efficiency rating than the heavier inverters have.

~CA

[PPOSS]

I hope you have some big batteries. 1200 watts will take 100 amps and a 3000-watt inverter can pull 250 amps at 12 volts. My microwave pulls more watts than my a/c. These are the last two things I want to use on an inverter.

[Vicr]

Aims PICOGLF25W12V120AL


I just read the spec on this inverter and the "PEAK" efficiency is 88%. In my experience reading electrical specifications on a regular basis The "peak" efficiency is usually at no load. I'd really like to see an inverter with a spec of at least 85% efficiency at least at half of its rated true load capacity.

[deepsea5]

Originally Posted by craigav

Hi Vicr,
One caveat though, if I needed to run a low power device overnight such as a cpap, and I you wanted to use an inverter to do that, then I would have two inverters, a small one that is rated around 2~300w and then a larger one (2500w +) for overall RV usage at other times. As related to Vicr's point there is also power cost just with turning on an inverter, not to go deeper just keep in mind that a smaller inverter would be more efficient for lower wattage needs than using a large inverter for a very low wattage need.) ~CA

My wife's CPAP (Philips Respironics) can also be run off a 12V "cigarette lighter" type cord (no inverter necessary). The person who issued and set up her CPAP actually gave her this cord. This spring I will be installing a marine grade 12V "cigarette lighter" type receptacle on our TTs bed nightstand for this reason.

[craigav]

Originally Posted by deepsea5

My wife's CPAP (Philips Respironics) can also be run off a 12V "cigarette lighter" type cord (no inverter necessary). The person who issued and set up her CPAP actually gave her this cord. This spring I will be installing a marine grade 12V "cigarette lighter" type receptacle on our TTs bed nightstand for this reason.

That is what I would do as well, run the cpap off of 12v if at all possible. I don't use a cpap although I have heard from some that state their cpap can't run at 12v, in which case I would use the smallest inverter possible (+150% still) to carry the load or get a cpap that could run at 12v, which would be the best option for sure instead of using an inverter. Thanks ~CA

[craigav]

Originally Posted by PPOSS

I hope you have some big batteries. 1200 watts will take 100 amps and a 3000-watt inverter can pull 250 amps at 12 volts. My microwave pulls more watts than my a/c. These are the last two things I want to use on an inverter.

Hi PPOSS,
You are very correct, a lot of people don't realize that they would need some hefty batteries and along with some hefty cabling to support even a 1200w inverter load for any length of time.

I had planned to go fulltiming (with a lot of boondocking) before Covid hit and since that time I have now changed my plans, with fulltiming in mind I purchased a lot of items that I haven't installed yet and not sure I ever will. One of which is I have a little over 500amps of Lifepo4 batteries that I no longer plan to install all of them anymore as I will not need that much for battery reserve with my current plans, and I would rather save the storage compartment room for other items.

In fact, I certainly do not recommend to anyone to invest in a large inverter unless they have a specific need to do so, as running the generator in the morning and evening (as needed) would be a much more cost efficient option for running the microwave a few times per day and it is good to "exercise" the generator regularly anyway.

~CA

[Bakedalaskan]

I have the Aims 2000W inverter charger. It says it has 30 amp pass through capability but in actuality it does not. It does appear to have 300% surge capacity for 20 seconds. Craigav; you may easily test my theory on the bench before you install. I had an entire weekend of camping to find out what mine would and would not do because I had to live with my install for that period of time. 2000 watts is plenty for what I need and the inverter does a great job. The disappointment was that it will not pass 30 amps of shore power like it says it will and this is the reason for my post to warn you to test it first. Once you know what it can or can't do you will then have a better idea of how to install it. There have been some good ideas in this post. The 30 amp auto transfer switch may be the ticket. I do not have an onboard generator which is one reason for the inverter. It saves the generator set up time while trying to make lunch on the road and lets us use our electric blanket on those side of the road overnights in some chilly places. There is no substitute for a generator but I don't want to be that guy we all talk about because he has to run his generator 24 hours a day.

[craigav]

Originally Posted by Bakedalaskan

I have the Aims 2000W inverter charger. It says it has 30 amp pass through capability but in actuality it does not. It does appear to have 300% surge capacity for 20 seconds. Craigav; you may easily test my theory on the bench before you install. I had an entire weekend of camping to find out what mine would and would not do because I had to live with my install for that period of time. 2000 watts is plenty for what I need and the inverter does a great job. The disappointment was that it will not pass 30 amps of shore power like it says it will and this is the reason for my post to warn you to test it first. Once you know what it can or can't do you will then have a better idea of how to install it. There have been some good ideas in this post. The 30 amp auto transfer switch may be the ticket. I do not have an onboard generator which is one reason for the inverter. It saves the generator set up time while trying to make lunch on the road and lets us use our electric blanket on those side of the road overnights in some chilly places. There is no substitute for a generator but I don't want to be that guy we all talk about because he has to run his generator 24 hours a day.

Thanks for the tips BakedAlaskan,

I think this is the manual for yours,
https://www.invertersupply.com/media...20W12V120V.pdf

Interestingly enough, in your manual (not in mine) it states that the bypass breaker is 30a however just under that it says the GFCI breaker (plug) is only 15a.

I would be interested to know if you were plugging into the gfci outlet on the inverter or hardwired? I had thought about simply plugging mine into the receptacle on it (for easy removal if needed) however now I believe I will have to hardwire it in for even a chance to have all 30 amps passed through (as my gfci plug likely has a 15a breaker as well). If the one I purchased can't pass the 30a via the internal transfer switch, I will add a 30a transfer switch as you mentioned, to keep things simple.

Thanks again, Craig

[Bakedalaskan]

Mine is hardwired. Never even considered the GFCI port because mine is not accessible the way it is installed. The document you have is a little different than mine because my manual covers all Aims inverters through 6kw. Your document reads almost word for word to mine. Craigav; you sound like you have technical skills so it would be relatively cheap to build two jumpers to put your inverter between shore power and the camper and start turning things on to see what will pass through. My inverter may have a faulty circuit but all the other parameters of the inverter have been accurate for the last 2 years. I just wish I knew the shortfall before installation, I would have done a different install.

[craigav]

Originally Posted by Bakedalaskan

Mine is hardwired. Never even considered the GFCI port because mine is not accessible the way it is installed. The document you have is a little different than mine because my manual covers all Aims inverters through 6kw. Your document reads almost word for word to mine. Craigav; you sound like you have technical skills so it would be relatively cheap to build two jumpers to put your inverter between shore power and the camper and start turning things on to see what will pass through. My inverter may have a faulty circuit but all the other parameters of the inverter have been accurate for the last 2 years. I just wish I knew the shortfall before installation, I would have done a different install.

I had watched quite a few youtubes regarding these inverters prior to purchase, and the one (or two) I saw regarding the fan modification did show the internals along with the transfer relay which looked pretty small and cheesy to me. I haven't taken the cover off of mine (yet) however I think I will do that and do plenty of testing prior to permanently installing it. Maybe beef it up a little where possible to do so.

With your information, I also think I will cable in a 30a twist lock for the input and output connections so I can easily bypass the inverter in case of a failure.

Here is a youtube of why not to buy an Aims inverter. Lol, Don't anyone watch it though if profanity offends you (F-Word +++ Warning), I found it very entertaining.

Update:
I decided to delete the link, as it is not appropriate for everyone, if anyone wants to see it, search youtube for "Do NOT buy an AIMS inverter for your motorhome!"

Thanks again, ~CA

[Mahatnmacoat]

I think I've found a simple solution. I drew a picture, just black and white lines but every line labeled. First, I need a bigger inverter, at least 3kw continual duty. Put in a marine off/on battery switch between the battery bank and the inverter. Click, battery disconnected from the inverter.
Next I found a 30 amp ATS for a hundred bucks. American made, very highly rated especially by RV users. So, here's the plan. Down stream from the shore/genset and the inverter outputs, put the new ATS. The inverter I'm going to buy has both plugs and a terminal block for hard wiring. Output from the new ATS to the service panel. The shore power and the genset will not be energized, that's why I need the inverter. Yes the whole AC system will be energized but the coffee maker and microwave outlets are all I'll be useing.

Lean over to reach the service panel, click off the charger, click on the inverter. Poof, coffee and oatmeal. Driving down the highway, crockpot in the sink bubbling away, (A BRILLIANT IDEA). Stop somewhere, want to plug in or light up the genset, click off the battery inverter switch, click on the charger breaker. Poof, set the table and turn on the TV.

Holding my breath for myriad replys.

Thanks be to so many.

[Johnynorthland]

Originally Posted by Mahatnmacoat

I hope Grumpy or Craigavon or Pconroy or JimD get a look at this question. I want to hook up a one thound watt inverter to power the two outlets in the kitchen, one is the galley GFI the other is the microwave. The power stream is either shore power or genset to auto transfer switch, from transfer switch to service panel. From service panel 30 amp main to 15 circuits. Two 15 amp circuits to the galley. The inverter is a pretty good one, Xantrex. Two 15 amp three prong outlets on the output end.

The transfer switch and the service panel are close to each other and right over the house battery bank. I'd like to switch the 30 amp main OFF, the inverter ON, make my coffee cook, up my oatmeal and read the paper. It would be nice to have a failsafe switching setup so there's no chance of turning the main and the inverter on at the same time but I trust myself to make sure it's either or.

I'm sure I'll get some good back feed and thanks in advance.

My plan is to use this 2200 Watt unit

https://www.amazon.com/dp/B07CKBJ9KP...ing=UTF8&psc=1

in my Redhawk and either run 3 outlets or tap into 3, (kitchen, midship by TV & my router and bedroom TV). It also has a built in 20amp PWM solar charge controller, even though its not as efficient as an MPPT charger controller it’s still will charge lead or AGM’s, and can always be upgraded.

[Red Wing]

Do an analysis using ohms law to calculate your usage and what the inverter will be pulling from the battery bank. You may be surprised to find out how many amps at 12 volts are required to get 30 amps at 120 volts. You mentioned that you had a genset. That may be your best option.

[JimD]

The quickest method of getting in the ballpark of how much current is required at 12 volts is to just multiply the output current by 10. This assumes 100% efficiency which you will never achieve.

The reason for this quick estimate is because you can not get something for nothing. At 100% efficiency (in our dreams), the wattage out would equal the wattage in. 120 volts is 10 times 12 volts, once again ballpark. So, 1200 watts at 120 volts equals 10 amps (10 x 120) and 1200 watts at 12 volts equals 100 amps (12 x 100).

Here is a link to a battery site where you can input your requirements and it will give a decent estimate of input current. For the 10 amp output, the site showed 110.4 amps input draw. Groan, give me a generator!

https://www.batterystuff.com/kb/tool...-inverter.html

[David Sinclair]

Originally Posted by craigav

As a thought, if you are looking at a larger inverter, consider one that has a charger and a transfer switch built in. For example, I have tested in my shop but yet to install it is a green Aims 2500 watt inverter that has a built-in transfer switch. My plan is to feed the input of it the power line going to the breaker panel, and the output going into where the breaker panel main input is located. That way all plugs will be hot when on inverter power or shore, or generator power and I can choose what to turn on and off just like if the generator or shore power was available.

I also mentioned the charge circuit, because it has a charge circuit all you have to do is unplug the current converter\charger. If you choose another brand (many good ones out there and likely better than AIMS) then you may need to consider a way to power off the charger\converter as you wouldn't want that to be on while using the inverter.

Just a thought to share, as this is my plan.

~CA

Hi look at this unit it has everything you want in one unit. It is not cheep but with everything in one unit you avoid al the extra wiring costs. Also if you planning on using both outlets you should go with a 2000 watt unit.
Good luck with it!

[Red Wing]

Jimd, I agree using the 10 times method. Some folks do not realize how much battery they will need to supply an inverter and run their AC appliances. Sometimes a small genset is the best answer. Also a French Press and a tea pot make good coffee. Just say'n.

[Vicr]

Originally Posted by Red Wing

Jimd, I agree using the 10 times method. Some folks do not realize how much battery they will need to supply an inverter and run their AC appliances. Sometimes a small genset is the best answer. Also a French Press and a tea pot make good coffee. Just say'n.

See post #17.