Help choosing an inverter please

jrcent

I just got an Edecoa 3500 pure sine inverter  for about $300. So far it it good. No big loads on it but specs look good. If it lasts long enough to save money for a name brand then I'll be happy.  It's probably only  1500w or less  but it's quiet and fan not constantly running so far. 

Model No.: 3500W-24V

Continuous Output Power: 3500W

Max Output Power: 7000W

DC Input Voltage: 24V ( 21-28V)

AC Output Voltage: 110V/120V

Frequency: 60Hz

Efficiency: 88%

No Load current Draw: 0.5A

Output Wave Form: Pure Sine Wave

Inversion Efficiency: 90%

Temperature Protection: (75℃)

Input Low Voltage Protection: YES

Input Reverse Polarity: YES

Output Short Circuit Protection: YES

Overload Protection: YES

Certification: CE, EMC, LVD

Input low voltage protection, overload protection, over temperature protection

Reverse polarity

Automatic voltage regulation(AVR)

Intelligent power management (IPM)

Intelligent Fan Control (IFC)

I also  just got a  Morningstar 300w inverter to be my night system (work in progress but connected to my coach batteries for now). Nice heavy quality piece! 

mcgivor

jrcent said:

I just got an Edecoa 3500 pure sine inverter  for about $300. So far it it good. No big loads on it but specs look good. If it lasts long enough to save money for a name brand then I'll be happy.  It's probably only  1500w or less  but it's quiet and fan not constantly running so far. 

Model No.: 3500W-24V

Continuous Output Power: 3500W

Max Output Power: 7000W

DC Input Voltage: 24V ( 21-28V)

AC Output Voltage: 110V/120V

Frequency: 60Hz

Efficiency: 88%

No Load current Draw: 0.5A

Output Wave Form: Pure Sine Wave

Inversion Efficiency: 90%

Temperature Protection: (75℃)

Input Low Voltage Protection: YES

Input Reverse Polarity: YES

Output Short Circuit Protection: YES

Overload Protection: YES

Certification: CE, EMC, LVD

Input low voltage protection, overload protection, over temperature protection

Reverse polarity

Automatic voltage regulation(AVR)

Intelligent power management (IPM)

Intelligent Fan Control (IFC)

I also  just got a  Morningstar 300w inverter to be my night system (work in progress but connected to my coach batteries for now). Nice heavy quality piece! 

The one limiting factor is the input voltage range, particularly the 28V maximum, that's lower than lead acid charging voltage, usually the upper limit is >30V. With lithium ibatteries it may be ok but I could see it being a nuisance with LA.

jrcent

Curious what the limit variation is for these specs ?  Right now I'm using  agm but was about ready to get some gc2 batteries. I have a charge controller for a  windmill that has a diverter mode. I can set the diverter for 28v if it causes issues. 

BB.

Assuming you are far north (USA) or in Canada, with Lead Acid (and AGM) batteries, cold weather requires higher charging voltages (most solar charge controller automatically up the charging setpoint as the batteries go down to freezing and below).

With a very cold battery bank, seeing 30-32+ volts charging is not unusual (for a 24 volt battery bank). Some industrial batteries when cold even go a bit above 32 volts charging/equalizing.

I don't live in cold weather climate, but from what I have read, I would not use an AC inverter with less than 30 VDC "alarm/shutdown", and would suggest getting a 32+ volt rated input inverter--If you plan on running the system very cold weather and charge (you could shutdown the inverter while charging as an option).

28 VDC is pretty low... The typical FLA battery charges around 29-30 VDC at room temperature.

-Bill

jrcent

North Idaho 16 miles from the Canadian border so definitely gets colder here.  

If I keep the batteries inside so  as not  to get  below  room temperature maybe that would help?  Assuming that the inverter will last till winter,  hopefully I will have a better inverter than and won't have the issues. 

BB.

The problem is that 28 volts translate to 14.0 volts charging (on a 12 volt battery bank)... That is a relatively low voltage for charging a FLA or even AGM battery bank.

FLA (at 25C/77F) should charge at 14.75 volts (29.5 volts) absorb setting (AGM should be around 14.4 or 28.8 volts) to quickly and fully recharge for nominal conditions.

With your inverter, you have a couple options:

• run 29.5 volts (absorb) charging and see if the inverter alarms or shuts down (you could contact technical support and see what they say).
• Run 29.5 volts charging and shutdown the inverter during charging.
• Run 28 volts charging and set float to 28 volts too. Once a week, turn off the inverter and run 29.5 volts charging and hold absorb for 2-6 hours (shallow discharge ~2 hours, deep discharged ~6 hours).

I forgot if your batteries are FLA or AGM... FLA--Monitor the water usage (check all cells once a month, and you should need to add water around every 1-3x per month--for typical water usage). If you have to refill more than once a month, crank back charging voltage/time.

AGM are more difficult--But as long as you do not exceed 14.2-14.4 volts (28.4 to 28.8 volts) charging (room temperature) and the batteries do not make 'noise' (no boiling noise, no venting noise) and stay relatively cool--they should be OK.

-Bill

jrcent

12v agm 100 ah. Right now my charge voltage is staying around 28.5 max. Just a basic  charger with a 440 amp relay .

So as long as my charge controller and batteries are "sized" correctly then this inverter will be the only issue if voltage is over  28v ?  I need to make sure that the next inverter I get will be designed  for 32+ volts. 

This inverter was designed for a car or just a low quality unit? 

Tecnodave

I am using a MagnaSine MS-4024AE that I bought real cheap as the fans run all the time and the only solution that Magnum energy can provide is new boards at considerable expense. It does make it a bit noisy, but it's in a power shack with the other power units so I don't hear it. The former owner replaced it with a new one due to the noise which he could hear from his bedroom. Other than that it is rather slow to regulate voltage when a large load comes on. This is a known issue that others have reported. If I were to choose between the two I would have purchased the Outback unit. But at 1/8  the price I hobble along with the Magnum awaiting the soon to be released MidNite Rosie, a 4000 watt unit soon to be available in 24 and 48 volt versions. I had used my Cotek SK1500 much more that the Magnum until it failed last week. I had bought that one for $200 on flea bay new, and it ran flawlessly for 8 years before going silent. I am now using a Exeltech XP-100 unit that I have used for 8 years now. I do run dual inverters as a habit as my electric needs are small at most times, I only use the big ones when I need lots of power. The Exeltech is superior to all the others in one area, it is very silent on the radio bands as it is very low EMI/RFI and does not interfere with my radios and sensitive electronic gear and medical devices.  

As paulcheoung  has noted Magnum does have an issue with the cooling fans that they have not resolved so the fans being stuck on is not a problem for me, they draw less than 10 watts or so, my idle power is just over 50 watts so tolerable

KenMorgan

both outback and magnum are great units, as well as some of the older xantrex (freedom) designs.  Aims is nothing but horror stories but I think that is because too many folks are not thinking it through.  the outback, magnum and the other "good" inverters are all invariably low frequency designs with a huge transformer coil inside.  this allows for better handling of surge loads and transient peaks than the HF designs and are probably what does in the HF designs which is what the AIMS inverters all are.  that being said, Samlex/Cotek are all HF as well yet seem to have less issues then the cheaper units. 

Tecnodave

KenMorgan,

The Outback and Magnum designs are technically high/low frequency designs as the driver electronics are high frequency but drive a low frequency transformer. This gives these units great reserve power to drive big loads without overloading. The high frequency units do not have anywhere near the overload capability. The only true low frequency unit still in use is the Trace SW Units that are so legendary, they are 60 hz electronics.

I have 2 of the original high/low frequency units, The Dynamote Brutus, ancient, obsolete, but will not die. They are 24 volt 3200 watts continuous duty but with a whopping 11,200 watt surge capability, far greater than my MagnaSine MS4024 which at 4000 watts continuous power has a 5800 watt surge capability. The only drawback to these units is a horrid 96 watt idle. I still use one to drive a deep well pump that my MagnaSine has a problem starting. I use a Trace XT-240 Autotransformer as the Brutus is 120 volts only. These were the original Northern California pot grower off grid inverters, that is where I got them. My Brutus transformers are much larger than my MagnaSine units, even larger than the Schneider's that I have peeked in. The Brutus easily handles any reactive load which will choke most inverters.

jrcent

Thank you for all the responses!  There is so much information on this forum that I have to digest. 

Today I had someone tell me that they were the go to  solar expert for the area. He told all he would install are aims inverter because they are the best in the world and all technology for solar inverters came from them. He also said he never installs solar batteries because they aren't worth the money. Pick the highest  CCA and I would be good.  I had to laugh to  myself and say wow. I was thinking of all the information I have read here about aims and smile. 

I am really rethinking the way I am doing this but still have a lot to learn. 

mcgivor

jrcent said:

Thank you for all the responses!  There is so much information on this forum that I have to digest. 

Today I had someone tell me that they were the go to  solar expert for the area. He told all he would install are aims inverter because they are the best in the world and all technology for solar inverters came from them. He also said he never installs solar batteries because they aren't worth the money. Pick the highest  CCA and I would be good.  I had to laugh to  myself and say wow. I was thinking of all the information I have read here about aims and smile. 

I am really rethinking the way I am doing this but still have a lot to learn. 

This someone has no idea what they are talking about, enough said. 

Tecnodave

Jrcent,

I say exactly what' McGivor said, that person does not have an idea,  Cold Cranking Amps has nothing to do with capacity and AIMS is the worst of the worst if not then next to the worst.

Good inverters...Outback, MagnaSine,Schnieder, Exeltech, Cotek...

just my humble opinion