I feel a tad dirty, but curiosity does kill the cat here.I've been noticing a few relatively cheap 20-40 amp MPPT controllers from China, sold at either ebay shops, or places like mppsolar.com. The pictures and YouTube vids show decently sized inductors and other critical components.While it doesn't have the bells and whistles of a good Morningstar, the price is right, it can increase volts/amps for the different battery voltages, and the reviews show that the amps/volts/watts meter is accurate enough.Anyone have any good/bad results with these no-named charge controllers? The cost saved by buying one of these can likely net me a couple more decently sized panels or maybe another storage battery or two.

Hardly a no-name in this case. Huge company. I have a LandStar PWM Series (not Shunt)controller that is just fine. Their MPPT version is the Tracer.http://epsolarpv.com/en/index.php/Product/index/id/95/am_id/134Tracer MPPTs are more expensive at approx. $180 than the $40 items from the no-name outfits in the OP, but if the no-namers did a good job of copying ??? they should be ok, especially where you can see how they did in back-yard testing as mentioned.IMO there is something not so funny about MPPT pricing. The MPPT is just a PWM with an add-on part. Must be a heck of a part to make the unit now cost hundreds more!! (probably costs at least 50 cents to make :( )So good for these no-name guys breaking up the party the big guys have been having at our expense! The Market Place is at work (finally! )

Remember a good Product Manager will price the offering at what the market will bear which should have limited to no relationship to what it costs to manufacture unless you’re into selling commodities aka groceries or similar everyday stuff Quality MPPT controllers are not yet in that catagory

Hi,There is also the fact that a good MPPT is really a dedicated computer and the design of the MPPT algorithm is not cheap. Folks do need to be compensated for their creativity, not just the parts and labor to assemble them.

A lot of those expensive MPPT controllers have more features too.

The only reported success of a cheaper MPPT controller was the Eco-Worthy one. Can never remember who owns it though.EDIT: It was JimInDenver. Eco-worthy 20a MPPT controller

Feel dirty by asking... Generic MPPT solar CCs?

46 Replies

BFL13
Explorer II
Jul 12, 2013
The local guy I am dealing with charges $1.08 per watt (tax included) whether 12v or 24v so it all 'depends' how the economics fit. Shipping panels is the killer at any voltage.

I don't know what he will charge for his next batch of panels whenever they arrive from China (later this month?--slow boat etc etc ) OTOH he has so far had a very limited selection of controllers. ( He is mostly a wind turbine guy and grid tie solar guy with a one-man-band home business, so low overhead is the key here)

There is no doubt that RVers are 'low volume' when it comes to solar
JiminDenver
Explorer II
Jul 12, 2013
mena661 wrote:
Also, pricing doesn't seem to work in my favor for two panels vs one as the super cheap CC's can't be programmed. And I need to be able to lower float voltage in the summer.

Both the float and absorb voltage is adjustable with the Eco-worthy.
BFL13
Explorer II
Jul 12, 2013
Just go by the shadow on the ground lining up with the panels. Main problem is I need a loose string along just above the top to keep all the robins from perching there, pooping down the panels. They don't use the one on the roof--too far from the worms. But a seagull got that one with a big ugly splatter one time. Yuk.

Now if MPPT gave off a falcon noise.....
pianotuna
Nomad III
Jul 12, 2013
Hi BFL,

Ummm twirl using a shadow with a pencil held to the edge of the frame of the panel. I hear they are cheaper than a trimetric......
BFL13
Explorer II
Jul 12, 2013
There is roof real estate and then there is real real estate. Naturally, for solar I use both :)

I am hoping to try out an MPPT on the contraption set.

Don't need to pay extra for MPPT to get more AHs. If I run short of AH leaving the panels facing South, I just twirl the contraption (for free!) and get some more AHs.

The Trimetric is a HUGE part of all this. You wouldn't know whether to twirl or not without it :)
pianotuna
Nomad III
Jul 12, 2013
Hi BFL13,

The panels I chose were 53.8 x 29.2 inches. There was plenty of room for four--and I probably could have squeezed in six.

BFL13 wrote:
So it is a battle between those who say to get smaller panels but more of them so the smaller panels will actually fit in the various roof spots; whereas a big panel won't fit anywhere----and those who say get MPPT (which is required for the big panels that won't fit anywhere.) Makes sense to me! :)
mena661
Explorer
Jul 12, 2013
BFL13 wrote:
So it is a battle between those who say to get smaller panels but more of them so the smaller panels will actually fit in the various roof spots; whereas a big panel won't fit anywhere----and those who say get MPPT (which is required for the big panels that won't fit anywhere.) Makes sense to me! :)
Whether or not big panels fit depends on the RV. Had PLENTY of space on my old 5er and surprisingly not enough on the MH. Also, pricing doesn't seem to work in my favor for two panels vs one as the super cheap CC's can't be programmed. And I need to be able to lower float voltage in the summer.
BFL13
Explorer II
Jul 12, 2013
So it is a battle between those who say to get smaller panels but more of them so the smaller panels will actually fit in the various roof spots; whereas a big panel won't fit anywhere----and those who say get MPPT (which is required for the big panels that won't fit anywhere.) Makes sense to me! :)
JiminDenver
Explorer II
Jul 12, 2013
True

My 230w panel with a rated SOC of 8a would be kind of a white elephant on PWM only.
mena661
Explorer
Jul 12, 2013
IMO, going MPPT is not necessarily fine tuning. BFL, you keep leaving out people with 24V and above panels. There is no choice of PWM in those cases unless your battery bank is 24V or more or you just like leaving amps on the table. So there! :B :P

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Feel dirty by asking... Generic MPPT solar CCs?

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