diy solar

diy solar

adding a 320w panel to a 160w system

what confuses me is the volts can be higher on the solar panel than the battery, but does it mean that it will just reduce the volts to 12v and push more amps when it hits the charge controller to charge the battery? which is why I would need a 30 amp controller?

This is exactly how an MPPT solar charge controller works. My panels produce about 80 volts. My MPPT controller converts that down to the 13 to 14 volts that my batteries need.

I know this is cheap but im assuming this would work?


As I said before, I don't know the PWM controllers that well. I keep looking for the Max PV Input Volts in the specs and can't find it. Maybe it doesn't matter.
 
I can only see 30a charge controllers that do 12v or 24v and from the spec it says like 380w for a 30a at 12v. So i think it converts it down like an mppt especially when you can edit the volts on the unit.
 
Last edited:
Last edited:
Yeah I did see them but the cheap Chinese one has been great on my 160w panel.

If I bought this could I tie it into my electric? If im spending 100 on a mppt should i not consider a tie in grid and battery charger?
 
Yeah I did see them but the cheap Chinese one has been great on my 160w panel.

If I bought this could I tie it into my electric? If im spending 100 on a mppt should i not consider a tie in grid and battery charger?

The cheap Chinese PWM solar charge controller works because your existing panel has limited voltage and wattage. Once you step up to the big boy panel, it's a whole different ball game.

I don't do grid-tie, so I can't provide any guidance on that device. But I will say that you should keep your system simple. Don't make it any more complicated than you have to. Panels of different specifications on the same circuit = complicated.
 
to be clear because the messaging so far has not been.

For a MPPT controller they have a min voltage to operate (if you don't reach this voltage then they don't output anything) and they have a max voltage they can accept. Exceed the max and you'll burn it up.

If you within the 2 ranges, it will convert the that incoming voltage to an output that its designed for.

as an example the MPPT in my 48v growatt all-in-one has an allowable range of 60-115v the 24v version is 30-115v. They are both 80a output MPPT so the 48v version will support 4kw of pannels were as the 24v only supports 2kw.

So there is an advantage to higher voltage systems however at the size your currently playing with its unimportant.
 
If im buying a 320w solar panel which is 40.06v and 10.27 amps then i would have thought this would do it



What confused me is the listing says 12v.is 200 odd watt solar and 24v for 500w panel?

I want to run mine on 12v battery
 
Victron controllers can be over-paneled. I would have no hesitation putting that controller with a 320 watt panel. You likely won't get the full amps that the solar panel could produce (~26 amps theoretical), but you'll get a solid 15 amps for sure with full sun.

You could step up to the Victron MPPT 100/30 to get as much as 30 amps to the battery (assuming you have a slightly bigger panel than 320 watts). It will work just fine with the 320 watt panel without leaving any amps on the table.
 
MPPT usually costs more. Victron costs even more.

Other brands to look at are EPever and Renogy. Renogy has some issues with quality control and poor customer service lately, so I would be reluctant to consider them. Will Prowse has a video out there that compares a few solar charge controllers. Find that and it may help you find a good one.
 
Again-you need a 30 amp controller to harvest all the power a 320 watt can produce. The victron you linked will give you 15amps max...
 
Yes it makes sense, what doesn't make sense is these 30amp controllers that say 30a for 12v/24v but don't say what input the panel volts it can handle.

Just to confirm I could run this mppt and my current cheap Contoller on the same battery?

Thanks

Lee
 
watching that video I have come to the conclusion that the PWM wanderer is the best and cheapest as it doesn't do anything different from the MPPT even in cloudy conditions. Only thing to be mindful of is the temp sensor as its a lead battery im using.
 
Back
Top