Newbie - Can my 48V chinese controller charge my 12V battery bank in my motorhome?

[carlcbilodeau]

I am a newbie. I know almost nothing about solar technology except that I read a few hours on internet before I purchased my panels and controller. I plan to "do it myself" since I am used to work on electricity.

I have a motorhome with four 12V deep batteries in parallel (96ah each I think and I should add one). This is a 12V system.

I have bought two 24V 305W panels that I plan to put in series.

I have bought this MPPT 48V controler from aliexpress. It will arrive home in three weeks and it is already shipped.

This controller is coming from China so I don't think I can not ship it back when it arrives. This morning I told myself: "Will my controller be able to charge 12V batteries or is it a controller for 48V batteries?". Did I make a mistake here?

I think my controller name is : "WS-MPPT60 60A Solar Charge Controller Wellsee". I searched on the Internet and I think these links link1 and link2 show my controller.

Carl

[inetdog]

I am a newbie. I know almost nothing about solar technology except that I read a few hours on internet before I purchased my panels and controller. I plan to "do it myself" since I am used to work on electricity.

I have a motorhome with four 12V deep batteries in parallel (96ah each I think and I should add one). This is a 12V system.

I have bought two 24V 305W panels that I plan to put in series.

I have bought this MPPT 48V controler from aliexpress. It will arrive home in three weeks and it is already shipped.

This controller is coming from China so I don't think I can not ship it back when it arrives. This morning I told myself: "Will my controller be able to charge 12V batteries or is it a controller for 48V batteries?". Did I make a mistake here?

I think my controller name is : "WS-MPPT60 60A Solar Charge Controller Wellsee". I searched on the Internet and I think these links link1 and link2 show my controller.

Carl

The first link you give is indeed for 48V batteries only. There is also a good chance that the MPPT function is a fake, based on the price.

[carlcbilodeau]

The first link you give is indeed for 48V batteries only. There is also a good chance that the MPPT function is a fake, based on the price.

I just took the product name and I searched it on the web. I think some seller don't advertise it clearly. Base on my readings it is a 12v/24v/48v charger that takes 48v panels.

Thank you.

[jony101]

it looks like it can charge the 12 volt batteries, according to the description it can do 12/24/48 volts battery banks.

But I see a problem on the panel voltage input, if you connect you panels in series, it would be more voltage then it can handle for 12 volts. Your panels are too powerful for it, even one panel might put out too much voltage. It says it can only handle a max panel voltage of 20 volts for 12 volt batteries. Since your panel is 24 volts it might work barely but only one (or if you connect 2 in parallel) but if you connect in series it will be 48 volts an will burn out the controller.

Another thing I see is that it is a mppt controller in name only. A real mppt controller would be larger due to the giant toroid (a big donut looking thing with copper wire circling it). All true mppts have the toroids. In youtube there are reviews of the wellsee mppt and they are all actually pwm controllers. Even the cheap actual chinese made mppt are in the 100+ dollar range.

But to get full use of you panels you do need mppt. Just an example from my system which is a 240 watt panel.
I tried using 2 different controllers.
mppt controller = I get 13 amps of power
pwm controller = I get 7 amps of power

If you do get the controller to work, it will only be giving you half (or less) of the power that your panels can produce.

My advice get a dc wattmeter and connect it between your controller and battery, that way you know how much volts/amps/watts your controller is putting out, they only cost about 15 dollars. The controller your getting has no digital display and the blinking lights will be useless.

[carlcbilodeau]

it looks like it can charge the 12 volt batteries, according to the description it can do 12/24/48 volts battery banks.

But I see a problem on the panel voltage input, if you connect you panels in series, it would be more voltage then it can handle for 12 volts. Your panels are too powerful for it, even one panel might put out too much voltage. It says it can only handle a max panel voltage of 20 volts for 12 volt batteries. Since your panel is 24 volts it might work barely but only one (or if you connect 2 in parallel) but if you connect in series it will be 48 volts an will burn out the controller.

Another thing I see is that it is a mppt controller in name only. A real mppt controller would be larger due to the giant toroid (a big donut looking thing with copper wire circling it). All true mppts have the toroids. In youtube there are reviews of the wellsee mppt and they are all actually pwm controllers. Even the cheap actual chinese made mppt are in the 100+ dollar range.

But to get full use of you panels you do need mppt. Just an example from my system which is a 240 watt panel.
I tried using 2 different controllers.
mppt controller = I get 13 amps of power
pwm controller = I get 7 amps of power

If you do get the controller to work, it will only be giving you half (or less) of the power that your panels can produce.

My advice get a dc wattmeter and connect it between your controller and battery, that way you know how much volts/amps/watts your controller is putting out, they only cost about 15 dollars. The controller your getting has no digital display and the blinking lights will be useless.

I have also a 255W panel. So I can use this controller for this panel and buy a bigger one for my two 305w panels with a big donut.

I have bought a watt meter. I will install it and verify how many amps of power I get from my cheap controller. I will probably have to buy one with big donut for this 255w panel too.

Many thanks
Carl

[Naptown]

Another useful feature of that comtroller is it is thunder protected.
It is important to protect against thunder 😁

[carlcbilodeau]

it looks like it can charge the 12 volt batteries, according to the description it can do 12/24/48 volts battery banks.

But I see a problem on the panel voltage input, if you connect you panels in series, it would be more voltage then it can handle for 12 volts. Your panels are too powerful for it, even one panel might put out too much voltage. It says it can only handle a max panel voltage of 20 volts for 12 volt batteries.

.....

Jony,

Here is the official link from the manufacturer.

I think it can take my 48V panel base on what I read. What do you think? Maybe you had a different description as this one?

[inetdog]

Jony,

Here is the official link from the manufacturer.

I think it can take my 48V panel base on what I read. What do you think? Maybe you had a different description as this one?

Did you look at this line in the table?

Input voltage range 12V~20V / 24V~40V / 48V~80V

What this means is that when charging a 12V battery the input voltage range is 12V-20V (and I do not believe that 12V would actually work. Maybe 15?)
And when charging a 24V battery bank the input voltage range is 24-48V.
Similarly when charging a 48V battery bank the input voltage range is 48-80V.
Or maybe the low end number is just the cross reference to the nominal voltage and the only meaningful number is the higher one.

In any case, I do not necessarily believe that it really does MPPT based on the specifications. Nowhere does it state that output current will be greater than input current. Just that it will run the panel at a higher voltage (and probably throw away the increased power as heat in the controller.)
Research it well on the internet for real reviews. Start here: http://www.amazon.com/Instapark-MPPT...ews/B004XCQ7AS

[Sunking]

Did you look at this line in the table?

What this means

What it really means it is a cheap counterfeit POS Chi-Com junk. It is not a MPPT controller. Bottom line to get a real and quality MPPT controller they are going to cost $5 to $8 per amp. That may seem high but is a lot less expensive than a PWM or counterfeit controller. Of th eMPPT controllers there are only a handful of quality manufactures out there.

That POS controller you have is going to turn your 600 watt panels into 120 watts. Good luck with that on a 12 volt battery. All you need to do is buy another 4 panels to get to 600 watts, or spend $400 on a real 45 amp MPPT controller like a MorningStar TriStar TS-MPPT-45. Hell of a lot cheaper than Chi-Com PWM to actually get the full 600 watts you expect.

[SunEagle]

Did you look at this line in the table?

What this means is that when charging a 12V battery the input voltage range is 12V-20V (and I do not believe that 12V would actually work. Maybe 15?)
And when charging a 24V battery bank the input voltage range is 24-48V.
Similarly when charging a 48V battery bank the input voltage range is 48-80V.
Or maybe the low end number is just the cross reference to the nominal voltage and the only meaningful number is the higher one.

In any case, I do not necessarily believe that it really does MPPT based on the specifications. Nowhere does it state that output current will be greater than input current. Just that it will run the panel at a higher voltage (and probably throw away the increased power as heat in the controller.)
Research it well on the internet for real reviews. Start here: http://www.amazon.com/Instapark-MPPT...ews/B004XCQ7AS

I actually saw somewhere in a document that while they claim the CC is a MPPT type they use Pulse Width Modulation (PWM) charging protocols.

[Willy T]

I actually saw somewhere in a document that while they claim the CC is a MPPT type they use Pulse Width Modulation (PWM) charging protocols.

Which is possible since mppt is only active during the bulk cycle and PWM would be active during absorb cycle.

[SunEagle]

Which is possible since mppt is only active during the bulk cycle and PWM would be active during absorb cycle.

That part I understand which is why I did not bash the equipment although based on it's size and cost IMO is not a true MPPT CC.

The problem is that the data from the CC is not specific enough as to what battery voltage is can charge and what input voltage is required for that battery voltage. Very confusing.

[inetdog]

I actually saw somewhere in a document that while they claim the CC is a MPPT type they use Pulse Width Modulation (PWM) charging protocols.

Yes and no.
In a typical PWM environment the switching element is either on or off. The result is that during Bulk the switch is always on and the panel voltage is close to the battery terminal voltage.
When the CC is in Absorb or Float, the PWM is maintaining the desired average voltage on the battery terminals. The panel voltage measured will be the average (weighted by pulse duty cycle) of Voc and the battery terminal voltage.

What the Wellsee does is a combination of deliberate IR losses inside the controller and using a less than 100% duty cycle even during Bulk to artificially increase the voltage measured at the panel.

The net effect is that even in Bulk the Wellsee delivers a lower current than a normal PWM CC, just so it can display a higher panel voltage.

I have to agree with the reviewers who call this a deliberate fraud against the the consumer that not only does not deliver what it claims but actually delivers poorer performance than an admitted PWM CC would.

[Willy T]

That part I understand which is why I did not bash the equipment although based on it's size and cost IMO is not a true MPPT CC.

The problem is that the data from the CC is not specific enough as to what battery voltage is can charge and what input voltage is required for that battery voltage. Very confusing.

They need someone to re-write their manual and ad copy to be compliant with the industry understandings. It's so often that way with the Chinese.

[carlcbilodeau]

...

The net effect is that even in Bulk the Wellsee delivers a lower current than a normal PWM CC, just so it can display a higher panel voltage.

I have to agree with the reviewers who call this a deliberate fraud against the the consumer that not only does not deliver what it claims but actually delivers poorer performance than an admitted PWM CC would.

So I lost money.

It increase my previous estimate budget by 80%. It would be frustrating to put 800$ on two controllers ... to save 25% wattage on a total 1000$ panels.

Maybe I should keep this one for the 255w panel and purchase a cheap 3-stage PVM 60A for my two 305w in series and add another panel to add 25% for the lost of the PWM. This solution would cost me 400$ instead of 800$.