Welsee mppt Temperatur sensor

System

hi,
I bought the Mppt30 controller from Wellsee
At the specification they discribe a Temperature sensor
I cant place the controller close to the batterie in my case, so the
temprature has to be captured externaly

To use the controller correct I have to find the Temperature sensor inside the controller and connect the sensor via a externel cable.

Has somebody a glue where I can find the component which is resposible for the temprature detection.
How is the component labeld and how is it labeld at the PCB ?

Greetings from Germany ...

harley64

Cariboocoot

Re: Welsee mppt Temperatur sensor

Welcome to the forum.

I'm going to suggest two things.

First, read this thread: http://forum.solar-electric.com/showthread.php?t=9482&highlight=Wellsee

Second, see if you can get your money back on the Wellsee and buy a charge controller that has a remote temperature sensor (RTS) which includes just about every reputable brand of MPPT controller such as Morningstar, Outback, MidNite Solar, Xantrex, et cetera.

In all likelihood relocating an internal temperature sensor would not work due to the increased resistance from the length of wire needed to connect it.

System2

Re: Welsee mppt Temperatur sensor

I use one 190 Wp Module at my mobile home. May be I upgrade it with a second Module that size in a few years.
I bougt the Wellsee controller used in Ebay for about 70 US$
As far as I know, I need at least a 15 A unit and 30 A for 2 modules.
From Morningstar controller cost at least 5 times the price. I dont want to pay that much.
The question are:

Is the sensor a need independend from the battery type ?

What happends if the temprature Sensor makes wrong messurments ( I think allways less values, because the batterie is close to the engine, the MMPT is behind my seat)

If I find the sensor at the pcb, I have to extend the cabel for 2 meter. Then I should have better results as with the internal sensor.

Is it better do switch to that controller ( tribble Price ) but external sensor and display: http://www.ivt-hirschau.de/index.php?language=en&cPath=9

Is it better to use a controller withot mmpt instead of that china grap. ? (double Price)
http://www.svb24.com/electric+lighting/solar+panels+wind+generators/solar+regulators/votronic+solar+regulator+sr+110+165+240+324.html

Hope you can understand my writing

Cariboocoot

Re: Welsee mppt Temperatur sensor

I'd say you are correct in that a 190 Watt panel is capable of putting 10 Amps into a 12 Volt battery, so a 15 Amp charge controller is a good idea. Also that 190 Watt panel is likely a "24 Volt" type with a Vmp around 35 and as such an MPPT controller is required in order to make use of the full panel power at the lower system Voltage.

I don't think you're going to be happy with the Wellsee, as per the thread there are some doubts as to its actual ability to function as an MPPT controller.

Temperature sensors are not essential, but they are a good idea. In this case the battery is located near the engine, so it will likely be hotter than if it were in some other location. Under those circumstances the sensor will cause the controller to reduce the Voltage to the battery, keeping it from over-heating from too much charge. If it were in a colder location the sensor would cause the controller to increase the charge Voltage to compensate for the lower temperature.

These remote temperature sensors are specific to the controller they were designed to work with. They are basically a thermal-sensitive resistor on a fixed length of wire. If you change the length of that wire (as in moving an internal sensor 2 metres away) you will change the over-all resistance value and the controller will no longer receive correct information to compensate for the temperature difference.

So you have to use an MPPT type controller because the panel Voltage (I presume) is higher than the system Voltage.
You should have a remote temperature sensor, if it is at all possible to get a controller that has this and is within your budget.
You can't move the existing temp sensor because the resulting reading will be wrong and the battery will not charge properly.
You should not relocate the charge controller under the hood with the battery as the extra heat will definitely shorten its lifespan.

waynefromnscanada

Re: Welsee mppt Temperatur sensor

harley64 wrote: »

Morningstar controller cost at least 5 times the price. I dont want to pay that much.

Morningstar is the one that will do the job properly. Remember that old saying (in North America anyway) You get what you pay for.
A used $70 controller? No thank you. Sorry to tell you, but it is probably $70 wasted, that could have gone to a good controller, like the Morningstar. Sometimes the only way to go, is to spend the money and get what does the job properly.

System2

Re: Welsee mppt Temperatur sensor

Thanks for your help
I changed my mind and sell the china stuff.
It looks like that I will buy the MPP 320 digital duo
which is very commen in Germany as well as OEM from MobileTechnogie
If interested you can see details there:
http://www.solarlink.de/laderegvotronic.htm

It was testet good and has a external temperature messurement and a second output for refresh of the start Batterie.

It is possible that I can get it for about 230 US$ instead of 320 US$ list price.
Far away from my starting 70 but I think a good desission.

A additional question: This controller has a 320W limit. What happend if I connect
380W ( 2x 190 W) panels on it. I think you never get the listet power out of a modul.
With double size and 80 % output the controller shoud work.
Is that correct, or should I buy a 120 W in a few years in addition to my 190 w ?

Cariboocoot

Re: Welsee mppt Temperatur sensor

harley64 wrote: »

A additional question: This controller has a 320W limit. What happend if I connect
380W ( 2x 190 W) panels on it. I think you never get the listet power out of a modul.
With double size and 80 % output the controller shoud work.
Is that correct, or should I buy a 120 W in a few years in addition to my 190 w ?

The major concern with input limits on an MPPT controller is to not exceed the maximum input Voltage with the panel(s) Voc. A few extra Watts is usually no problem as charge controllers are rated by their maximum Amps output @ system Voltage, but you probably won't get the benefit of them.

In other words the 320 Watt limit is probably based on 15 Amps output at charging Voltage plus a margin for derating since the panels will rarely see their "nameplate" Wattage. You should check with the manufacturer to be certain.

As for putting a 120 Watt panel with a 190 Watt panel you have to be sure that the specifications on the panel are close enough so that you're not wasting power. Since this is an MPPT controller with a 150 Volts input limit (if my German is good enough to pick that out) you could wire the panels either in series or in parallel. For series wiring (Voltage goes up, panel current remains the same) you need the two panels' Imp to be close. For parallel wiring (Voltage stays the same, panel current goes up) you need the two panels' Vmp to be close and you need the wire to be able to handle the combined current. I mention this because your 190 Watt panel is "24 Volt" whereas a 120 Watt panel is likely to be "12 Volt" in which case you can not wire them in parallel.

System2

Re: Welsee mppt Temperatur sensor

you can change the language to english clicking the German Flag

Cariboocoot

Re: Welsee mppt Temperatur sensor

harley64 wrote: »

you can change the language to english clicking the German Flag

What fun is that?
I like to keep my brain challenged. These days just about everything does.