Best option to optimise this winter...

[Entwicklung34]

Hi there,

Got some great help from expert members on here setting up a small 4 x 100w panels in series-parallel / 3 x110ah 12v battery / 30a mppt system with 1200w inverter for light house usage like charging devices and lighting etc. Here's the thread if it's useful: https://diysolarforum.com/threads/200w-solar-system-expectations.40326/page-9

I'm wanting to make the best use of this system this winter for lighting and whatever else I can get as it's been doing really well in the summer but wondering about the winter when it's really overcast...

The mppt manual says for my controller four 100w panels is the max to be connected to it but I was wondering if it would be acceptable to add another two panels in the winter as they won't generate at full capacity anyway? (They don't even in the full summer sun... Most I've seen coming in from the four panels is 215w at 36v) ... Or, I'm wondering would I be better investing in another battery to add to my existing 3 batteries?

I don't have a massive amount of money to add to the system but another two panels or another battery is doable and just wanted to see what would be the best option so any thoughts most welcomed!

 

[Bobert]

What chemistry are your batteries?

 

[Entwicklung34]

What chemistry are your batteries?

Sorry they are lead acid (wet) batteries

 

[Bobert]

Sorry they are lead acid (wet) batteries

Adding batteries can be problematic. If your batteries are newish and you don’t expect to upgrade them lifepo4 soon I would suggest increasing the size of your bank. As fla batteries age their performance drops and if you add new batteries the new ones will essentially drop to the performance level of the old ones so the less age difference between your batteries the better. If you plan to go with lifepo4 or Something else in the near future the expansion of your batteries will be a waste of money unless you have an absolute need for the additional storage.

 

[Entwicklung34]

It's all a fairly new system so batteries are what I would deem fairly new... First bought on Feb22, 2nd bought in March22 and then 3rd bought in July22. All the exact 'same battery' as such and connected in parallel.

Wondering about over-panelling the system in the winter to collect more during the 2 hours of decent daylight we'll get here in the UK ?

 

[Sirtate]

It's all a fairly new system so batteries are what I would deem fairly new... First bought on Feb22, 2nd bought in March22 and then 3rd bought in July22. All the exact 'same battery' as such and connected in parallel.

Wondering about over-panelling the system in the winter to collect more during the 2 hours of decent daylight we'll get here in the UK ?

Over panelling is OK.
One caveat; make sure that your Voc doesn't exceed the max voltage of the controller....

Overpanelling is like plugging a phone charger into an outlet after removing a hairdryer. The potential for more wattage is there, but the phone charger only pulls what it needs.
(as long as you don't plug something made for American mains (120V) into your British 240V outlet)

 

[Entwicklung34]

Over panelling is OK.
One caveat; make sure that your Voc doesn't exceed the max voltage of the controller....

Overpanelling is like plugging a phone charger into an outlet after removing a hairdryer. The potential for more wattage is there, but the phone charger only pulls what it needs.
(as long as you don't plug something made for American mains (120V) into your British 240V outlet)

Makes sense - thanks for this