Vicron MPPT charger and the 5v+ startup rule

[seafox67]

Last week I purchased a Victron SmartSolar 75/15 charger and installed it ready for the new mono panels.

With issues of boat space, I am going for 1 x 30w panel and 2 x 50w panels all with a 17.8V output.
The plan is to configure them in parallel which will hopefully stop the 30w panel causing performance issues.

I'm a little concerned now that I may never reach the +5v (above battery voltage) rule for the charger to start charging the battery.

Is anyone using a similar installation that can offer some advice?

Thanks
Paul

 

[noelex]

Paul, is 17.8v the open circuit voltage (Voc), or the maximium power point voltage (Vmp)?
Do you have wind generator, or other form of charging apart from the alternator?

 

[seafox67]

Paul, is 17.8v the open circuit voltage (Voc), or the maximium power point voltage (Vmp)?
Do you have wind generator, or other form of charging apart from the alternator?

17.8v is the Vmp.
22.3v is the Voc.
I will only have solar, no wind generator.

Thanks

Paul

 

[noelex]

You should be fine, Paul. The Victron may occasionally be slightly slower to start than would be absolutely optimum, but any loss of power, especially in a colder climate, is likely to be very minimal.

The test is to look at the current produced at start up. It should be very low. It would be great if you could post your results.

 

[seafox67]

The test is to look at the current produced at start up. It should be very low. It would be great if you could post your results.

I will be happy to post the results.

I'm getting the first 30w panel on Monday which will go just in front of the spray hood (Westerly Tempest).
These panels are German made rigid mono.
If the test goes well, the plan is then to get two 50w versions of this panel and fit them either side on top of the spray hood.

Paul