MPPT controller or larger solar panel?

[Phantom]

As a low power user with a 120w solar panel and a PWM controller, which is the better upgrade, a MPPT controller or a 300w panel? A MPPT controller is about the same price as a cheaper 300w panel, so either up to 30% more efficiency or 250% more potential power respectively. I guess that the larger solar panel would far out weigh the lower light charge benefits of MPPT for about the same cost? Both together would be the most efficient of course, but no good if you can't store it or need to use it! On the face of it the larger panel alone seems to about double the benefit?
But then again just for the geekyness of it I do quite fancy the Victron controller for the Bluetooth app!

 

[landoboguy]

And for ease of fitting, the MPPT is the winner.

I have the Victron and yes, the bluetooth is a good little touch.

 

[Fisherman]

As a low power user with a 120w solar panel and a PWM controller, which is the better upgrade, a MPPT controller or a 300w panel? A MPPT controller is about the same price as a cheaper 300w panel, so either up to 30% more efficiency or 250% more potential power respectively. I guess that the larger solar panel would far out weigh the lower light charge benefits of MPPT for about the same cost? Both together would be the most efficient of course, but no good if you can't store it or need to use it! On the face of it the larger panel alone seems to about double the benefit?
But then again just for the geekyness of it I do quite fancy the Victron controller for the Bluetooth app!

Make sure your current controller can handle a 300w panel.
Also what about batteries.
In winter storage capacity is more important than harvesting capacity.
I have a Victron 100/20 controller and two 120w panels and two 95a batteries.

 

[Mr and Mrs Tupcox]

Buy both .
Search for this on fb markrts place looks like poss bargain.

 

[Mr and Mrs Tupcox]

Even cheaper, as

 

[Mr and Mrs Tupcox]

Bluetooth is just a geeky thing expensive extra does nothing to help with power ..
Just fit controller were you can see it.

 

[edina]

Bluetooth is just a geeky thing expensive extra does nothing to help with power ..
Just fit controller were you can see it.

Not quite correct, having bluetooth enables it to communicate with things like battery smart sense, which means it can alter the charge to suit the battery temperature

 

[Mr and Mrs Tupcox]

Not quite correct, having bluetooth enables it to communicate with things like battery smart sense, which means it can alter the charge to suit the battery temperature

I stand corrected.
But is it needed .if your mppt controller does this .is it not just an extension of your controls .using Bluetooth. ,?

 

[trevskoda]

Im not a battery watcher either, duel regulator for engine and hab batts is the way to go, mind you not much use in deep winter.
You can get these with higher inputs on ebay.

 

[colinm]

If you are looking at the £150 panels, these are quite high voltage, I'm not sure if they would be suitable with your present regulator, someone with better knowledge might know.

 

[st3v3]

As long as your controller can support it, definitely get the new panel.

Then the victron stuff later lol.

 

[Fisherman]

Not quite correct, having bluetooth enables it to communicate with things like battery smart sense, which means it can alter the charge to suit the battery temperature

To give actual battery temperature and voltage you need one of these below.
This gizzmo transmits information to your controller using Bluetooth.
you can get one with a 10m Bluetooth range also, but I find the 4m range fine.
But if your battery is more than 3m from the controller I would pay extra for the 10m model. Also you only need one even if you have more than one battery.

OFF COURSE THIS IS ONLY COMPATIBLE WITH VICTRON CONTROLLERS.

And I totally agree bluetooth is an excellent thing to have.

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[Fisherman]

If you are looking at the £150 panels, these are quite high voltage, I'm not sure if they would be suitable with your present regulator, someone with better knowledge might know.

The nominal voltage is around 22-23v Dc.
You require the charging voltage to be higher than 12-13v Dc.
Some folk find this confusing when ordering panels for a 12v system.

 

[jagmanx]

Whilst I am no expert
1 an extra panel will provide more power
2 MPPT controller will assist in charging.
3 The various "monitoring toys" are handy but do not change the situation.
4 We all know winter is difficult
5 See how it goes.
6 Depending on your preferences EHU sometimes

 

[Fisherman]

With regards to the original post.
If you intend using your van in winter when there is hardly and solar power to harvest what is most important is not harvesting capacity but power storage.
Maximising battery capacity is much more important than harvesting in winter.
Also mppt controllers c/w battery monitor will not only improve your harvesting but also increase the lifespan of your lead acid battery(s).
So rather than fit another solar panel for winter, I would invest in a second battery if you don’t already have one.

 

[maingate]

Im not a battery watcher either, duel regulator for engine and hab batts is the way to go, mind you not much use in deep winter.
You can get these with higher inputs on ebay.View attachment 88362View attachment 88364

Just fitted the MPP250 Trev as my old Schaudt LR1218 regulator failed. At the same time I sorted out the crap bodge job the Dealer made of running the cables. That's a good price in your link.

 

[colinm]

The nominal voltage is around 22-23v Dc.
You require the charging voltage to be higher than 12-13v Dc.
Some folk find this confusing when ordering panels for a 12v system.

I've only had 30+ years of using solar for charging batteries.
There are many cheap solar panels around which are between 30 to 40v, what I'm not sure of is if the OP is looking at these and if the present PWM regulator can handle this.

 

[Fisherman]

I've only had 30+ years of using solar for charging batteries.
There are many cheap solar panels around which are between 30 to 40v, what I'm not sure of is if the OP is looking at these and if the present PWM regulator can handle this.

I was merely trying to be helpful. If I offended, I do apologise.

 

[ricc]

With regards to the original post.
If you intend using your van in winter when there is hardly and solar power to harvest what is most important is not harvesting capacity but power storage.
Maximising battery capacity is much more important than harvesting in winter.
Also mppt controllers c/w battery monitor will not only improve your harvesting but also increase the lifespan of your lead acid battery(s).
So rather than fit another solar panel for winter, I would invest in a second battery if you don’t already have one.

if the solar wont charge one battery in winter i fail to see how a second battery charged only by the existing solar panel will store any more usable power. youd need to be either on hookup or driving to charge them.

 

[Fisherman]

if the solar wont charge one battery in winter i fail to see how a second battery charged only by the existing solar panel will store any more usable power. youd need to be either on hookup or driving to charge them.

Ok.
First before you leave home charge the batteries in your drive if you can.
If not hopefully the drive will do the job for you.
When you arrive for a two to three night stay regardless of harvesting capacity you are starting with two fully recharged batteries instead of one.
And obviously if you move elsewhere the same will apply.

Idealy you should also increase harvesting capacity.
But the OP has not indicated that he wishes to do both.

Any reading I have done on this subject always recommends increasing storage capacity over harvesting.