Any PV electronics experts out there?

May 9, 2018
I need some advice as to if I can safely exceed the input to my 10Amp MPPT solar charge controller.
It is rated at 130W max, but will it take 140W without ever it causing any problems?

I installed 2 solar panels to my campervan roof ( 50W & 80W) with a total rated output of 130W, and installed at the same time a 10Amp MPPT controler rated at 130W max... bought from the same supplier.
Both panels were either defective when installed, or failed shortly after. I never discovered this until, a month or so later on an extended holiday in Italy doing some off-grid camping and doing minimal driving, the leisure battery failed and I replaced it. But soon after, the new battery was drained and I then realized the battery was seing no benefit from the PV system. The suppliers have, after months of email exchanges requiring me to perform a range of quite technical tests, admitted both panels are goosed and the have agreed to replace them.
The trouble is that this supplier no longer stocks that range of solar panels (I wonder why?) and have offered me replacement panels from a limited range of output and sizes that are not identical to the originals. The upshot is that, given the limited available space on the van roof, I could end up with 2 panels totalling either 120W, 140W, or 160W.
Having planned for and paid for a minimum of 130W there is no way I'd go for 120W.
Having considered the other 2 options, and also assuming the supplier would also have to replace the 130W controller to cope with the extra wattage, I opted for the pair of panels totalling 160W... well, you would wouldn't you... especially as the cost to the supplier would amount to very little compared to my months of agro, tests, and emails. I'd consider it an apology or compensation for all the time & effort etc.
Anyway... the supplier claims that the 140W option would be fine for the 130W controller because "it can actually take a higher solar input than rated, as there is a function within it that allows it take a bit more power, so the 10W addition won’t be a problem".
So I'm now looking for informed second opinions.
Should I believe that a controller advertized, rated, and sold as a max 130W... will give many years of trouble free service despite being used beyond it's rated range?
I could ask the company to put it in writing, but that would only cover 1 year of warranty and then diminishing consumer protection to a max of 6 years, beyond which I would be on my own if damage related to exceeding that 130W should occur to controller or panels.

Any electronics experts out there?


Sep 20, 2011
pilchard said:
...Any electronics experts out there?
I’m near certain that you won’t find a current member of this forum able to advise on your complex enquiry (but I’ll be happy to be proved wrong).

I suggest you copy your enquiry to this free-to-join forum where considerable solar-panel-system expertise does exist.
(You’ll need to register first before posting to that forum.)

If you do this, you should identify the make and model of your 10Amp/130W-maximum MPPT controller (and the make/model of the two replacement solar-panels if you have that information). Although probably not relevant in this case, I suggest you also identify the make, model and age of your campervan.

I doubt if anyone will be in a position to assure you that your existing 130W controller will be able to cope long-term with a solar-panel system rated at 160W, and I’d anticipate the (perhaps obvious) advice to be that the controller should be replaced by a higher-rated unit.

As you DIYed the installation, it’s probably unrealistic to demand that the supplier of the defective panels provide you with a new uprated controller, but it should be possible to get a recommendation from the Out&AboutLive forum for the ‘best’ controller for your new panels.



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