Issues with AIMS inverter/charger

ckhd · May 2014

Hello everyone,

I have a co-worker who recently bought an AIMS PICGLF30W24V120V 24v 3KW inverter/charger with a built-in MPPT charge controller. He is having a terrible time with it.

I have not laid eyes on the system (he lives 30 miles out of town), but I do have 25 years experience with PV (my Dad's off-grid systems). I have had him test and try everything. He has 1.6KW in panels, and four L-16 batteries. It is all hooked up correctly (even the people at Northern AZ Wind & Sun, where he bought the inverter, say it's right).

My boss also has several years of PV experience (he lives off-grid and I helped him with his initial PV system choices). He has not laid eyes on the system either, but also believes it is all connected and set up correctly.

His problem is that his batteries do not charge well. He comes home from work (with the inverter being off all day and 10+ hours of nice AZ sun) and his batteries are in the low 24v range (verified charge state with a hydrometer). So, he fires his generator every evening to charge the batteries. They charge fine on the generator (charged state also verified with a hydrometer).

I have read every page in the manual, and there are literally NO adjustable settings for the MPPT charge controller portion, other than a battery type selector (which is set correctly according to the manual). We've gone over the 'correct' settings in the manual and he has verified his inverter is set the way it should be.
I have never had any experience with AIMS equipment. My experience is mostly Trace, Xantrex and Outback.

After lengthy discussions with my co-worker and boss, I have decided it has to be one of the three following things:

The inverter/charger is set/programmed incorrectly
The inverter/charger is faulty
The inverter/charger is poorly designed

What are your thoughts?
Do any of you have much experience with AIMS products?
Help!

Bowen

solar_dave · May 2014

Re: Issues with AIMS inverter/charger

I don't see any AIMS products on the Northern AZ Wind & Sun store.

What panels is he using? Sounds like it is not hitting the batteries enough.

Edit: the attachment shows your range of programming it looks like:

from http://www.aimscorp.net/documents/PICGLF30W24V120V.pdf

BB. · May 2014

Re: Issues with AIMS inverter/charger

As Solar Dave asks... What are the solar panels Vmp/Imp and how are they arranged?

Many people by "24 volt panels" which are actually Vmp~30 volts. In hot weather, you can see Vmp fall with temperature down by 20% to ~24 volts (plus wiring+controller voltage drop).

A "real" "24 volt panel" has rated Vmp in the range of ~35-38 volts or so (minimum).

With a good quality MPPT charge controller, a person would typically put two Vmp~30 volt panels in series to charge a 24 volt battery bank.

It looks like the Aims may be:

http://www.aimscorp.net/3000-Watt-Pure-Sine-Low-Frequency-Solar-Inverter-Charger-24-Volt.html

MPPT solar charge controller - PV in 30-55Vdc

If this is true, and the panels are "Grid Tied Style" panels (typically 60 cell / 30 Volt Vmp), two in series would be too high of operating voltage for this controller (sounds like it was designed for Vmp~18 volt or two in series for Vmp~36 volt panels).

All guesses at this point.

-Bill

ckhd · May 2014

Re: Issues with AIMS inverter/charger

Here it is:
* 12) Kyocera 140W 12V panels: http://www.solar-electric.com/kyocera-kd140gx-lfbs-140-watt-polycrystalline-solar-panel.html
* Voc at 10:00am was 20.1V per panel
* He has six parallel strings of two panels in series each. His Voc on each series string is 40.2V (at 10:00am)
* He tested the amperage while it was connected to the charge controller, and said each string was about 5.1A-5.2A. All six strings pegged his ammeter that had a 30A max. He didn't test the Isc.

Dave, That's all I saw on the programming too.

Did that give any insight?

Edit: Just talked to my co-worker, and you're right. He did NOT get the AIMS unit from NAZW&S... he got panels from them. They did tell him it was all hooked up right, though.

BB. · May 2014

Re: Issues with AIMS inverter/charger

Sounds correct...

Get a volt meter and measure the solar panel input voltage and the output voltage right at the controller/inverter's terminals.

Also, get an inexpensive DC current clamp / DMM like this one from Sears. You can start measuring current and see what is happening.

Also, how many Amp*Hours is the 24 volt battery bank? Any indication of how much solar array/charging current is going into the battery bank when the system is up and charging?

The Voc and current reading sound OK when panels tested individually.

-Bill

niel · May 2014

Re: Issues with AIMS inverter/charger

isn't that the brand coot always complained about?

ckhnd,
have you tried contacting aims about it as all else sounds correct? does he have access to another controller to see if bypassing the aims would work?

jonr · May 2014

Re: Issues with AIMS inverter/charger

ckhd wrote: »

* He has six parallel strings of two panels in series each. His Voc on each series string is 40.2V (at 10:00am)
* He tested the amperage while it was connected to the charge controller, and said each string was about 5.1A-5.2A.

He has ~1200 watts going somewhere. If nothing is running, it would be unlikely that this could be turned into wasted heat without noticing it. The batteries are known to be good?

vtmaps · May 2014

Re: Issues with AIMS inverter/charger

ckhd wrote: »

I have read every page in the manual, and there are literally NO adjustable settings for the MPPT charge controller portion, other than a battery type selector (which is set correctly according to the manual).

Does this controller have a remote battery temp sensor?

How does this controller decide how much time to spend in absorb? If you can't make absorb longer, you can try making it a higher voltage by selecting 'calcium' as the battery type. Be sure to watch water levels and battery temperature.

--vtMaps

Cariboocoot · May 2014

Re: Issues with AIMS inverter/charger

niel wrote: »

isn't that the brand coot always complained about?

ckhnd,
have you tried contacting aims about it as all else sounds correct? does he have access to another controller to see if bypassing the aims would work?

Yes.
You may also have noticed I frequently warn against these all-in-one units because of exactly this sort of problem. That is; no flexibility in the design.

My advice is: get rid of it and buy quality equipment that actually works. 1600 Watts of panel should have no trouble charging a single string of L16's as it ought to put out 50 Amps on 24 Volts. The KD140's are true 12 Volt panels so as long as they are configured in strings of two (or four) the Voltage should be high enough (barring serious wiring losses).

And no I do not work for NAWS.

ckhd · May 2014

Re: Issues with AIMS inverter/charger

Let's see:

BB: Batteries are Trojan L16re-a, so 325Ah.

Niel: The AIMS unit has no display other than a few LEDs.

Jonr: The batteries are good, and only three months old. He can run his generator, the batteries will charge and even reach a 'float' state according to the inverter. He has verified the charged state with a volt meter and a hydrometer.

vtmaps: This inverter has no bells or whistles.

Coot: Both my boss and I have Outback MPPT charge controllers. I had a discussion with my co-worker about getting a different charge controller, and he has decided that he will go buy a separate charge controller and bypass the built-in one. At this moment, he wants an Outback, I think because he knows two people that already have them, plus the NAWS guy showed him one and he was impressed with it. I did cringe when we first talked about his equipment and he said, "The MPPT charge controller is built in to the inverter". I also don't believe in putting all your eggs in one basket!

I believe his problem will be solved with a different charge controller.

The rest of the AIMS device seems to work fine, so he probably will just use it for the inverter/ac charger for now. I'm going to recommend to him that he starts saving a little to get a quality inverter down the road.

BB. · May 2014

Re: Issues with AIMS inverter/charger

Is that a single string of 325 AH batteries on a 24 volt bank? If so, that array is more than large enough to properly charge that battery bank:

12*140 Watt panels = 1,680 Watt array
325 AH * 29 volts charging * 1/0.77 panel+controller losses * 0.10 rate of charge = 1,224 Watt array for 10% rate of charge

5% to 13% rate of charge with 10%+ being a really nice sized array for a daily cycling battery bank.

-Bill

ckhd · May 2014

Re: Issues with AIMS inverter/charger

That's the conclusion we came up with too.

jcheil · May 2014

Re: Issues with AIMS inverter/charger

Cariboocoot wrote: »

Yes.
You may also have noticed I frequently warn against these all-in-one units because of exactly this sort of problem. That is; no flexibility in the design.

My advice is: get rid of it and buy quality equipment that actually works. 1600 Watts of panel should have no trouble charging a single string of L16's as it ought to put out 50 Amps on 24 Volts. The KD140's are true 12 Volt panels so as long as they are configured in strings of two (or four) the Voltage should be high enough (barring serious wiring losses).

And no I do not work for NAWS.

I and several friends have had nothing but problems with AIMS products. I received a DOA one, then the replacement lasted 2 weeks. I finally forced them to refund my money (Not NAWS; I can't remember where I got it).

Sure, they are cheap, but as you noticed, you get what you pay for. And your time is worth something right? So I agree, dump it NOW otherwise you will be spending more and more of your time messing with it until it finally dies at the worst possible time and leaves you stranded (or ends up killing your battery bank due to undercharging). All-in-one units are like all season tires. They "kinda do the job" but they are not really great in any specific condition.

BB. · May 2014

Re: Issues with AIMS inverter/charger

Assuming he has loads that are commenserate with the amount of solar panels:

1,680 Watt array * 0.52 system efficiency * 4 hours of sun (typical minimum for non-winter days) = 3,494 Watt*Hours per day

That is a good size system for a very efficient home (refrigerator, lights, well pump, washing machine, laptop, etc.).

If he is using >3kWH per day and/or has shading problems/cloudy skies (marine layer, etc.), then he would have a problem of using more power than the panels generate.

-Bill

stmar · May 2014

Re: Issues with AIMS inverter/charger

Out of curiosity, I clicked the link and looked at these inverters. First thing I noticed was that the price was half of a comparable Outback, Magnum, etc. If you watch the sales video you would think they are the second coming, military spec, bomb proof, etc. That is why it is good to have real world experienced people's input. I like my old SW4024 but know that someday I will have to change it out so will look at as many options as I can so that I will be ready when the time comes. Outback seems to be the front runner for now.

Triston · May 2014

Re: Issues with AIMS inverter/charger

Hello all. If I may. It may be the charge is not for solar, but only for the the Ac charging capability. I have been trying to research this inverter in order to make a purchase. I was under the impression the built in charger was non specific, but it would seem that it is not. Bypass built in charger and implement another. This litmus will determine if I buy one. Best of luck.

SkiDoo55 · May 2014

Re: Issues with AIMS inverter/charger

Link says it has a 60 amp Solar Charge controller built in plus a 40 amp line charger.

Stuck · May 2014

Re: Issues with AIMS inverter/charger

Hey guys,

I'm also looking at the AIMS units. For the price it's very tempting. I am looking at a Model #: PICOGLF80W48V240VS.
I've heard complaints about rf noise, and premature failure of units , but nothing on this model unit.

I also spoke to a csr online and the few things that stand out is 10% thd , and non functional dc inputs that he said was part of an older design that got carried over.

Any one use these and can shed some light on them?

Cariboocoot · May 2014

Re: Issues with AIMS inverter/charger

Note: 10% THD is so far off grid-quality power as to be unacceptable. It should be 5% or less. Good inverters are around 3%.

This thing sounds like an MSW inverter.

scheek · September 2016

Last week my 6000 watt low frequency AIMS inverter stopped working. First, the high voltage charger stopped and then later the inverter. I think the solar charger is still working but for the 2 years I have owned it, I have never been satisfied with the solar charger, but it did ok. I have contacted AIMS and they will fix it outside warranty but will have to evaluate the cost once they get it back. Well, I live in Mississippi and they are in NV. $150 freight one way. Now I don' know what to do. If it were just board replacement I could do that and maybe replace the FETS but I'm not getting input from tech at AIMS. This is an all-in-one unit. I would not recommend this for anyone. Component way would be best, especially if some part fails. My unit has an 85 amp battery charger for generator and 60 amp for solar. If I could salvage any part that would help. Has anyone ever worked on one or know of a way to salvage any part of he unit?

Issues with AIMS inverter/charger

Comments

Categories