MPPT Controller size and recommendation.

[canals are us?]

Sorry for my other electrical questions!

Liked the look of the Nasa BM2 so bought it!

I have a 30amp PWM solar controller with 4 solar panels totalling 380 watts. 2x80w 1x120, 1x100.

 Unfortunately I cant remember the voc of each panel but the max input of my old PWM TOPRAYSOLAR TPS 1230 Controller is 28v according to the manufacturers specifications. The panels are screwed down and posidrive head drilled out, so can't remove easily to check the label.

I want to replace it with an MPPT one, thinking from Bimble, but should that be 30A 40A or 60A? Thinking budget £150-200. What would you buy?

Technical specifications:
Max. solar input current:	30A
Max. solar voltage input (Voc) :	28V
Max. load current:	30A
Over discharge voltage:	10.7V±0.4V
Output voltage:	DC12V
No-load loss:	<25mA
Voltage loss charging circuit:	=0.4V
Voltage loss of discharging circuit:	=0.2V
Operating temperature:	-25° - +40°

Many thanks. James.

Edited January 31, 2018 by canals are us?

[luggsy]

We have 4 x 100 watt panels and a 40 amp MPPT 

[Richard10002]

You would probably be OK with a 30A Tracer, but might be worth a bit of future proofing with a 40A.

[WotEver]

11 hours ago, Richard10002 said:

You would probably be OK with a 30A Tracer, but might be worth a bit of future proofing with a 40A.

Agreed. The 30A is unlikely ever to run at full capacity in the UK. The only consideration is that the maximum voltage input isn’t listed in the above spec so we don’t know if the panels could be wired in series or not. Therefore they’ll have to stay in parallel. 

[Richard10002]

54 minutes ago, WotEver said:

Agreed. The 30A is unlikely ever to run at full capacity in the UK. The only consideration is that the maximum voltage input isn’t listed in the above spec so we don’t know if the panels could be wired in series or not. Therefore they’ll have to stay in parallel. 

I think the slightly cheaper Tracers (Model A with the display panel and the CN without a panel),  can handle 100V. The one I have, without a display panel, (Model BN), can handle 150V. 

Bimble sell the CN and the BN

http://www.bimblesolar.com/offgrid/mppt

[canals are us?]

Thanks everyone.

I think I'll play it safe and go for the 40A BN series controller and remote meter. Many thanks.

James

[WotEver]

22 minutes ago, Richard10002 said:

I think the slightly cheaper Tracers (Model A with the display panel and the CN without a panel),  can handle 100V. The one I have, without a display panel, (Model BN), can handle 150V. 

Bimble sell the CN and the BN

http://www.bimblesolar.com/offgrid/mppt

Well, if the old PWM one could handle a max of only 28V then the 4 panels in series could only give a max of 112V which would be comfortable for a 150V jobbie. 

However, I’m trying to work out if they could all go in series if they have a different MPP and a different Voc and I’m really not sure. Bimble would know. 

[canals are us?]

5 hours ago, WotEver said:

Well, if the old PWM one could handle a max of only 28V then the 4 panels in series could only give a max of 112V which would be comfortable for a 150V jobbie. 

However, I’m trying to work out if they could all go in series if they have a different MPP and a different Voc and I’m really not sure. Bimble would know. 

When I wired them originally I have them in parallel as advised from the good advice on here. Would you go with a 30A or 40A MPPT BM Controller?

James

[WotEver]

15 minutes ago, canals are us? said:

Would you go with a 30A or 40A MPPT BM Controller?

30A would cover what you have but might you buy another panel or two at some time in the future? If so then 40A would give you some scope. 

16 minutes ago, canals are us? said:

When I wired them originally I have them in parallel as advised from the good advice on here

But you’re changing your PWM for an MPPT now, so the advice might change. Ask Bimble

[canals are us?]

1 hour ago, WotEver said:

30A would cover what you have but might you buy another panel or two at some time in the future? If so then 40A would give you some scope. 

But you’re changing your PWM for an MPPT now, so the advice might change. Ask Bimble

Thanks I'll order the 40A one, as you say I may upgrade in the future.

I'll ask Bimble.

James