Selecting a new MPPT controller.

[rusty69]

I currently have 3 x 250W + 1 x 250W panels connected. The string of three are connected in series through a 60A controller, the 1 panel is connected through a seperate controller.

 

I would like to change the configuration to 2+2 in series, as one of the controllers is playing up and needs replacing.

 

I was originally considering the Tracer BN series (40A) controller, but upon browsing, came across these(Tracer 7810):-

 

https://www.bimblesolar.com/offgrid/mppt/Waterproof-Tracer7810BP

 

Now I know they are only rated at 30A (390W at 12V). My panels are 43 V open circuit,and they are flat mounted.

 

Would 2 of these controllers be ok, or should I go for the 2x40A?

 

Thanks as always

[WotEver]

I’d say the chances of 2 x 250W flat mounted panels exceeding 400W in this country to be slim to none.  So yes, I’d say you’ll be fine with 30A controllers. 

[rusty69]

1 minute ago, WotEver said:

I’d say the chances of 2 x 250W flat mounted panels exceeding 400W in this country to be slim to none.  So yes, I’d say you’ll be fine with 30A controllers. 

Ta. Any opinion on the controllers in the link. They look cheap. What am I missing?

[WotEver]

3 minutes ago, rusty69 said:

Ta. Any opinion on the controllers in the link. They look cheap. What am I missing?

I’ve read reports that the Tracers are slow to track and sometimes simply don’t track at all. These appear quite good at a similar or lower price:

https://www.makeskyblue.com/mobile/30a.html

[rusty69]

1 minute ago, WotEver said:

I’ve read reports that the Tracers are slow to track and sometimes simply don’t track at all. These appear quite good at a similar or lower price:

https://www.makeskyblue.com/mobile/30a.html

Thanks.It looks like it has a fan built in. I don't want one with a fan, as its the fan/controller that has just packed up on my exisiting one. Its also bl**dy noisy.

 

Thanks again.

[David Mack]

9 minutes ago, WotEver said:

I’ve read reports that the Tracers are slow to track and sometimes simply don’t track at all. These appear quite good at a similar or lower price:

https://www.makeskyblue.com/mobile/30a.html

An unknown name. Lots of warnings about fake products. They don't seem to have a UK distributor. 

Any independent reviews?

Edited August 13, 2018 by David Mack

[WotEver]

41 minutes ago, David Mack said:

Any independent reviews?

Phil Brooke-Little of the 12V FB group gives them a pretty favourable review. More keen to track than the Tracer and so far nothing bad to report. He’s tested three to date I believe. 

[Dr Bob]

I've got 2 * 150W panels via a 30A controller and rarely see much more than 20A coming in, even in the very sunny weather we have had. I bought a 20A victron mppt for my other two 100W panels and that is working well....but is a bit more expensive.

If it sunny enough for 30A in, your batteries will be charged pretty quick anyway so no point in going to 40A. 

Edited August 13, 2018 by Dr Bob

[rusty69]

7 minutes ago, Dr Bob said:

I've got 2 * 150W panels via a 30A controller and rarely see much more than 20A coming in, even in the very sunny weather we have had. I bought a 20A victron mppt for my other two 100W panels and that is working well....but is a bit more expensive.

If it sunny enough for 30A in, your batteries will be charged pretty quick anyway so no point in going to 40A. 

Well, as long as we don't get a really cold sunny day with a high midday sun, it should be ok. 

[Dr Bob]

Just read the link in your original post. The tracer works with LiFePo4 batteries as well so you'll be fine when you change to Lithiums later this year.

[rusty69]

Just now, Dr Bob said:

Just read the link in your original post. The tracer works with LiFePo4 batteries as well so you'll be fine when you change to Lithiums later this year.

They would cost more than Mr Rusty cost us! 

[Detling]

I have 600 watts of panels mounted flat. The maximum current recorder has been 37.5 amps so the controller has never had to  limit the current so I guess two 30s will have no trouble on 500 watts, may get to limit occasionally.

[WotEver]

22 minutes ago, rusty69 said:

Well, as long as we don't get a really cold sunny day with a high midday sun, it should be ok. 

As long as the voltage remains within the controller’s max then it couldn’t do any harm. All that would happen is that the controller would limit the maximum current to 30A. 

[rusty69]

24 minutes ago, WotEver said:

As long as the voltage remains within the controller’s max then it couldn’t do any harm. All that would happen is that the controller would limit the maximum current to 30A. 

The blub suggests 92v at 25 degrees c. Not sure if it varies with  temperature?

 

Eta. Looks like it does,so i may have to turn the array off if it falls below - 40!

Edited August 13, 2018 by rusty69