Help in understanding the data from my MT50 meter?

novaop · November 2017

Image: https://us.v-cdn.net/6024911/uploads/editor/l6/v53xktbye01p.jpg

I'm looking for help in deciphering/understanding the data presented in the posted image.
I understand that the Left most icon is info for the solar panel. The battery is the battery. The "light" icon deals with load.

It's the numbers- I'm trying to gain a better understanding of what these mean exactly in regards to the system....What is the example posted saying about what is going on with the system? THANKS SO MUCH!

Raj174 · November 2017

Welcome to the forum novaop,
It is saying that the battery is full and you have no load on the battery.
The PV input is determined by the battery. 37.2 x 1.1 = 40.92 divided by battery voltage 14.4 = 2.9 amps

Rick

novaop · November 2017

Raj174 said:

Welcome to the forum novaop,
It is saying that the battery is full and you have no load on the battery.
The PV input is determined by the battery. 37.2 x 1.1 = 40.92 divided by battery voltage 14.4 = 2.9 amps

Rick

Thanks. I've been browsing it for awhile and have seen a lot of helpful stuff. I created an acct. today to help me learn more about all this solar stuff. Just installed my system and I'm trying to learn and increase my understanding. Here's a specific question: The "load" icon : what does it mean when the little lines around the icon disappear/reappear?

novaop · November 2017

In regards to the solar - do the numbers under there represent only the power that's being provided to the battery? In other words they are not representative of the full power possible from the panels. So as the battery is drawn down the numbers would increase?

novaop · November 2017

What is the 2.9amps?? Is that how much is going into the battery? Or is that what is available in the battery? I'm very new to all of this and while I've been reading a lot....so far the light bulb of comprehension is not going on...only flickering.

novaop · November 2017

Ok....I've been playing around with my system and making a note of the numbers showing up on the meter. So when I turn on everything drawing power inside my camper.... the PV amps go up & so does the amps under the battery. Nothing happens under the load icon...no change. I thought the load icon was supposed to indicate the load....from things being turned on and using electricity. Is this not the case?

I'd like to add that the battery is showing fully charged and the sun is out while I'm doing this.

littleharbor2 · November 2017

The load icon is strictly for what may be connected to the load output terminals on the charge controller. It appears you don't have anything connected to those terminals. Best to leave it that way. If you must, connect only a low current item (such as a led light) which may be turned on and off by settings on the controller.

mcgivor · November 2017

The 2.9A is what's going into the battery at 14.4V, the PV is producing 37.2V at 1.1A which is down converted to the battery charging voltage, there is no load, hense 0.0A, the voltage at load terminals is 14.5V, which is strange because it's higher than battery voltage but not something to be overly concerned with, it's just a rough indication. As loads are applied the PV will attempt to support the loads resulting in the amperage increase indicated, if the loads are greater than the PV's ability to support them, current will be withdrawn from the battery, when loads are turned off, the amperage will remain higher, tapering down as the battery approaches full charge. The load terminals should only be used for small loads, any larger loads should be connected directly to the battery via an overcurrent device, fuse or breaker, higher end controller's do not have load terminals such as these

novaop · November 2017

littleharbor2 said:

The load icon is strictly for what may be connected to the load output terminals on the charge controller. It appears you don't have anything connected to those terminals. Best to leave it that way. If you must, connect only a low current item (such as a led light) which may be turned on and off by settings on the controller.the controller.

OK...that's what I thought but it's been surprisingly difficult to find CLARITY in figuring out this stuff. The "manuals" that came with this stuff are sooooo basic and don't really explain the who, what, when, where's of each of the numbers. The manual makes it seem as though the little dashes appearing around the bulb mean it's ON. On my display these go on and off at times? Why is that? Also it has occasionally shown .1A under the load icon. You are correct....I have nothing connected to the Load output terminals on the controller.

Spence_McCallie · November 2017

Littleharbor2 is right. The load icon is for another set of contacts on your charge controller. Usually, you can program the load contacts to perform a specific function. The most common is to wire a set of lights to the load contact and have the controller turn the lights on at dusk.

Most of us don't use the load contacts anyway, so don't worry about it.

novaop · November 2017

Thanks to those who've responded thus far. Things are starting to make more sense now. This is my first time using solar and I want to be sure I understand what these numbers are telling me. Another question....When there IS a load at night (no charging going on) (say I turn on some lights and fans) - then should I see a negative number on the amps under the battery? (showing amps being drawn?)

novaop · November 2017

Another observation/question..... I've noticed that the battery icon that is supposed to indicate the charge level does not seem to jive with reality. For instance....after the sun goes down this icon almost immediately drops to show HALF of full charge...even with zero draw - nothing turned on inside my camper. This freaked me out a bit when I saw it happen.......however the volts under the battery show it as 12.9, which I think is indicative of a full charge. Any thoughts??? Thanks.

Raj174 · November 2017

novaop said:

Another observation/question..... I've noticed that the battery icon that is supposed to indicate the charge level does not seem to jive with reality. For instance....after the sun goes down this icon almost immediately drops to show HALF of full charge...even with zero draw - nothing turned on inside my camper. This freaked me out a bit when I saw it happen.......however the volts under the battery show it as 12.9, which I think is indicative of a full charge. Any thoughts??? Thanks.

12.9 is the voltage reading of battery as it approaches resting voltage. It could take a couple of hours to reach final resting voltage. Something like 12.7

Raj174 · November 2017

novaop said:

Thanks to those who've responded thus far. Things are starting to make more sense now. This is my first time using solar and I want to be sure I understand what these numbers are telling me. Another question....When there IS a load at night (no charging going on) (say I turn on some lights and fans) - then should I see a negative number on the amps under the battery? (showing amps being drawn?)

It will not read negative reading because the MT50 is a charge controller remote, and only displays PV and charging information. However, the battery voltage will drop as loads are applied. If you want to see amp readings for loads you'll need a separate amp meter installed for that purpose.

Rick

mcgivor · November 2017

novaop said:

Another observation/question..... I've noticed that the battery icon that is supposed to indicate the charge level does not seem to jive with reality. For instance....after the sun goes down this icon almost immediately drops to show HALF of full charge...even with zero draw - nothing turned on inside my camper. This freaked me out a bit when I saw it happen.......however the volts under the battery show it as 12.9, which I think is indicative of a full charge. Any thoughts??? Thanks.

The battery icon is an indication of state of charge, whilst charging , not battery capacity indicator, or fuel gauge if you like, when the PV is charging and reaches ~14.4V the icon will be at or near to full, as soon as PV voltage drops below the battery voltage the display will appear to indicate loss of capacity, but it actually indicating a loss of voltage, a little misleading, having a real battery capacity meter would require knowing how much capacity was withdrawn verses how much is replaced......I wonder if the smiley face changes to

when the battery is completely dead?

littleharbor2 · November 2017

mcgivor said

I wonder if the smiley face changes to when the battery is completely dead?

It does.

fratermus · November 2017

novaop said:

Another observation/question..... I've noticed that the battery icon that is supposed to indicate the charge level does not seem to jive with reality.

The battery icon is infamously devoid of useful information. I advise ignoring it.

fratermus · November 2017

Raj174 said:

It will not read negative reading because the MT50 is a charge controller remote, and only displays PV and charging information. However, the battery voltage will drop as loads are applied. If you want to see amp readings for loads you'll need a separate amp meter installed for that purpose.

It really will show Amps going out the LOAD outputs.

fratermus · November 2017

Spence_McCallie said:

The load icon is for another set of contacts on your charge controller. Usually, you can program the load contacts to perform a specific function.
...
Most of us don't use the load contacts anyway, so don't worry about it.

I use my LOAD output to power house loads; this allows controller's low voltage disconnect to cut power at 12.2v or whatever. Since my loads can exceed the rating of the controller I run a relay off it, then run the actual loads through that.

novaop · November 2017

Thanks to all!! I'm gaining a much better understanding of what the meter is all about. I'm no longer freaking out.

Buraddo · January 2018

Thanks for the comments about the battery icon on the MT50. I was having little panics with it looking like I was haemorrhaging charge. Seems like a design fault if its intuitive use is so different from its actual intension.

Jixaman · November 2020

Buraddo, glad you posted that image, thats similar to what I have and think I'm not getting a charge to the battery. I have 13.9 and .1 at the panel icon and 12.8 and .1 at the battery icon.

Am I right then in saying I have (13.9x.1)/12.8 = .1085 amps coming from the panel. Does this mean my panel is broken?

And the 12.8 at battery, thats healthy, what is the .1a under that saying.

Many thanks...

littleharbor2 · November 2020

The current is that low probably because the battery is full.

BB. · November 2020

Buraddo,

You can make your own thread/discussion when we get into the details about your system... Will help us focus the Q&A on your needs and not confuse with Novaop's system.

Of course, the panel output depends on how much sun is hitting the panel under full sun... Nominally, the panel under full sun should be somewhere around 14.x to 20.x volts if PWM controller... And ~17.5 to 21.x volts if an MPPT charge controller under full sun.

So--First look, either your panel or wiring has issues (if under full sun), and if early morning or late afternoon--Cannot tell if good reading or not (panels approach Vmp to Voc under weak direct sun on an MPPT controller). If this is a PWM controller, the Vpanel is roughly Vbatt+ 1 to 2 volts (if charging) and Voc if battery is full.

Your battery voltage is also not telling us much right now... 13.5 volts is around "float voltage"--Where the controller "thinks" the battery if full and just enough voltage to keep the battery charged and supply any DC loads on your system.

Your controller seems to think the battery is 1/2 full--And if so, should be taking pretty much 100% of the solar array output and send it to the battery bank. If the battery is 1/2 full, it needs charging ASAP--Sitting at 1/2 charge for days/weeks--The batteries (if lead acid/AGM/etc) will sulfate pretty quickly. You do want to figure out what is going on pretty quickly... And/or get the battery bank on an AC charger for a day or two... FLA batteries need to be recharged around once a month. AGM can go upwards of 6 months between charging at 75F (25C). If the battery bank is stored "hot" (93F/35C or hotter)--need to be charged more often (and/or get them cooled down--Batteries age faster at higher temperatures)

Can you tell us the controller type (brand/model), your solar array (Vmp/Imp/Pmp, how many panels, series/parallel wired, etc.) type/voltage/AH rating of battery bank, and what your sun was (morning, noon, etc). And your rough location.

Do you have a hydrometer (if flooded cell batteries), and/or a decent voltmeter?

More or less, you want to see around 14.4 to 14.8 volts or so, and hold it for 2-6 hours (roughly 6 hours if bank is 1/2 charged)...

-Bill

littleharbor2 · November 2020

Can you send a picture of your MT-50? Surely it reads different than Buraddo's from 2018

New_Mexico_Will · November 2020

The little battery picture that displays how full the battery is is fairly worthless on the Epever charge controllers. I have 2 in parallel, and they don't even agree with each other.

They will also go up and down drastically with even small loads.

The real bummer is that when you parallel them or use the RS485 cable for something else, the MT50s will no longer work.

And, yes, Ive had the sad face. Not something you want to see!😩

Help in understanding the data from my MT50 meter?

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