Solar controller choice

[TrevandJenny]

We’re at Peterborough show and have found two dealers selling Victron controllers, As I have now upgraded my SP to 120 watts, (best I could do on Sargent 328 panel) fitted two new 100amp AGM batteries, I recall mentioned on here conversations regarding changing the solar controller to a MPPT,

With our 120 panel and 2x 100 AGM batteries what size controller do I require, reason for ask is as mentioned two dealers at show, one states 75/10 or 75/15 the other 100/15.
.
your advice appreciated

 

[Pudsey Bear]

Not sure what you need now but also consider first if you intend to increase your solar or batteries

 

[trevskoda]

Fit a votronic 250 duo to charge hab and start battery, you also require 200w of panels as you have 2 batts, rule of thumb is 100w for 100ah of battery.

 

[Pudsey Bear]

100w/100ah isn't always the case Trev, it's down to how many amps you use and need to replace.

 

[trevskoda]

100w/100ah isn't always the case Trev, it's down to how many amps you use and need to replace.

I only repete what i read and advice from the net, yes you could have less but then double the time to recharge, or very little on a dull day, hence the 100 to100 recomended.

 

[wildebus]

We’re at Peterborough show and have found two dealers selling Victron controllers, As I have now upgraded my SP to 120 watts, (best I could do on Sargent 328 panel) fitted two new 100amp AGM batteries, I recall mentioned on here conversations regarding changing the solar controller to a MPPT,

With our 120 panel and 2x 100 AGM batteries what size controller do I require, reason for ask is as mentioned two dealers at show, one states 75/10 or 75/15 the other 100/15.
.
your advice appreciated

Any of the above will work with your current setup.
You want to go for the SmartSolar rather than the BlueSolar if both choices are available.
Just to explain numbers for anyone wondering ... first number is maximum solar panel voltage. second nunber is maximum output current. so a 75/15 can have panel/s with a total voltage of 75V, and can output upto 15A.
PS. The total Wattage power is NOT 75 x 15. those are just the absolute maximums. the 75/15 has a maximum power of 220W (on 12V battery system); the 75/10 is 145W (IIRC).

Of the ones you list, I would go 75/15.
The 100/15 extra capability is something you will never need so why pay extra (I am assuming it is more expensive?). I would only get that if it was priced same as 75/15
The 75/10 limited current would stop you connecting an additional panel if you later decided to. Going for a 15A controller gives you future-proofing. the 75/10 is often no cheaper than the 75/15 anyway (in fact, when I have been asked for a 75/10, my supplier would quote me for the 75/15 as he got them cheaper!).

 

[TrevandJenny]

Thank you one and all, with advice as above it destroys the dealers thoughts at the show. Will the B2B still work if sargent controller changed to one of the ones as advised above?

 

[wildebus]

Thank you one and all, with advice as above it destroys the dealers thoughts at the show. Will the B2B still work if sargent controller changed to one of the ones as advised above?

The EC328 has the controller built in, as opposed to an external solar controller which you then connect to a "solar in" connection.
So my understanding would be if you get the Victron, you would connect its output to the battery direct rather into the EC328. Might be worth a call to Sargent to check the best way to do this?
The split-charge system in the EC328 will not be affected by the change.

 

[TrevandJenny]

Thanks again Wildebus, As suggested have spoken to Sargent, their advice was as yours, Thank you for your interest in this issue.