MPPT controller

[Tecka]

Hi all, I'm looking at putting a solar system onto my roof.

 

The panels are decided but I'm struggling to decide on controller. The choices are down to two and I suspect my ocd is about to cost me £100.

 

basically the problem is that all my equipment is mastervolt, I'm talking alternator, 3.5k combi unit, 4k remote invertor, battery charger plus all the gubbins. With the solar I'm putting on (3-4 flexible 100 watt) and the fact I'm 24v it means the mastervolt 25A MPPT would be a sensible option (giving limited expansion if needed)

 

The other option is a tracer 20A which is lower cost and doesn't give as much possibility for system expansion.

 

Is just my ocd wanting everything alike causing this compulsion to spend the extra £100 or is it reasonable?

 

Possible pertinent info.

 

All equipment out of warranty having been fitted donkeys years ago.

 

6 110ah batteries wired to 24v

[MtB]

Hi all, I'm looking at putting a solar system onto my roof.

 

The panels are decided but I'm struggling to decide on controller. The choices are down to two and I suspect my ocd is about to cost me £100.

 

basically the problem is that all my equipment is mastervolt, I'm talking alternator, 3.5k combi unit, 4k remote invertor, battery charger plus all the gubbins. With the solar I'm putting on (3-4 flexible 100 watt) and the fact I'm 24v it means the mastervolt 25A MPPT would be a sensible option (giving limited expansion if needed)

 

The other option is a tracer 20A which is lower cost and doesn't give as much possibility for system expansion.

 

Is just my ocd wanting everything alike causing this compulsion to spend the extra £100 or is it reasonable?

 

Possible pertinent info.

 

All equipment out of warranty having been fitted donkeys years ago.

 

6 110ah batteries wired to 24v

 

 

I think the Tracer will be fine provided you've done a power audit and established the 400W will be more than enough.

 

But will your OCD be troubled by this decision? Perhaps it is worth shelling out the extra £100 for the peace of mind that all the gear matches.

[sjc]

At 300W you are already beyond the max ( 20A ) output of the Tracer, 400W exceeds both options ! I suggest it is better to have spare capacity in the MPPT ( ie : get a 50A ) as it would allow for system expansion should you decide to do so, more importantly it will mean the MPPT runs cooler on a hot sunny day when the ambient temp in the electrical cupboard is high.

[MtB]

At 300W you are already beyond the max ( 20A ) output of the Tracer, 400W exceeds both options ! I suggest it is better to have spare capacity in the MPPT ( ie : get a 50A ) as it would allow for system expansion should you decide to do so, more importantly it will mean the MPPT runs cooler on a hot sunny day when the ambient temp in the electrical cupboard is high.

 

 

Can you show your workings for saying this please, because I disagree. 20A is plenty.

 

Don't overlook the fact that the OP's battery banks are 24v.

[sjc]

Yep, I completely missed the 24v point, in which case should be fine ! Never the less something for the 12 volters to consider !

[MtB]

In addition, I have 380w of solar charging 24v banks, and I've never seen more than about 8A flowing, according to the Tracer display!

Bright sunny morning now for example, charge current 3.9A on the display.

[WotEver]

In addition, I have 380w of solar charging 24v banks, and I've never seen more than about 8A flowing, according to the Tracer display!

 

Bright sunny morning now for example, charge current 3.9A on the display.

Don't forget that this will also be dependent on the battery SoC. You can't push 16A into a full battery.

[MtB]

Don't forget that this will also be dependent on the battery SoC. You can't push 16A into a full battery.

 

 

SoC is currently 64% according to the Smartgauge. Hazy sun now and 1.9A on the Tracer display.

[Robbo]

Hi all, I'm looking at putting a solar system onto my roof.

The panels are decided but I'm struggling to decide on controller. The choices are down to two and I suspect my ocd is about to cost me £100.

Have a look at the mastervolt, it may have some integration with your current system which may be useful, I know some of the victron mppts can hand control of the charging to the combis and also use the same display for monitoring, etc.