MPPT controller

Sep 24, 2013
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I want to fit a solar panel this summer and use an MPPT controller. Has anyone any experience of these and can recommend one that won't cost an arm and a leg? I've seen several on ebay and some from overseas. Has anyone had one of these and did they have any duty to pay?
 

Techno

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It depends on your personal view of "an arm and a leg"
I buy from Taiwan and often import duty of £16 is added if you are unlucky
The unit I use in its various marks has served me without issue for near four years since the mk1 version
 
Jan 22, 2013
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It depends on your personal view of "an arm and a leg"
I buy from Taiwan and often import duty of £16 is added if you are unlucky
The unit I use in its various marks has served me without issue for near four years since the mk1 version

I use the same type as techno and also without a problem, be careful on eBay though their lot that are listed as MPPT but are really PMW type that loose quite a bit in efficiency, so worth paying a bit extra then fit and forget,
MPP solar is the company that I used,

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Techno

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My most recent purchase of a 200watt model was hit for £22.19 this week.
This makes it £93 plus time and petrol collecting.
 
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vwalan

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i have been using pwm reg for years cant see its really worth changing it . far better to add another panel. even the panels i bought seconhand in morocco 14 years ago are doing ok .
first regs werent even pwm . but did a fair job .
 
Jan 22, 2013
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I agree if your system is already up and running and performing ok then I wouldn't incur the extra expense , but for somebody contemplating an new solar panel kit it worth paying the extra for an MPPT controller IMO ,
With my Two 100w panels giving out 40 volts joined in series,
I get on average 10 amp to the secondary leisure battery bank when needed in this country, and likely and bit more when abroad, it just maximises the panels output,
without having extra panels/ cable/ roof glans/ WEIGHT ::bigsmile:

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Jul 25, 2013
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I agree if your system is already up and running and performing ok then I wouldn't incur the extra expense , but for somebody contemplating an new solar panel kit it worth paying the extra for an MPPT controller IMO ,
With my Two 100w panels giving out 40 volts joined in series,
I get on average 10 amp to the secondary leisure battery bank when needed in this country, and likely and bit more when abroad, it just maximises the panels output,
without having extra panels/ cable/ roof glans/ WEIGHT ::bigsmile:

Sorry if this is a silly question but why have 2 100w panels when you can have 1 200w panel
Thanks
Dave
 

Techno

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It's all about dimensions. Could you fit a 200? I doubt it. There are other advantages to two panels over one but it has been said many times over already.
 

Techno

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A typical roof. Where would you put a 200 watt single unit even if it was beneficial

RG%203-M.jpg

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Daifuse

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My most recent purchase of a 200watt model was hit for £22.19 this week.
This makes it £93 plus time and petrol collecting.

I got hit too, this week. I also had to pay £22.19, £14 HMRC and £8 charges (?) but it's fitted and seems to be doing the job. (It should do after costing £87.00!)
 

Techno

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My 300watt MPPT hit and surpassed the magical 20 amps between the clouds on Saturday.
This very easily keeps the voltage well above the 12.5 volt cut off of my CBE CSB2 that allows my solars to supply my 160 litre fridge freezer.
A PWM regulator would struggle as it spends 25% of it's time turned off by the nature of how they regulate.
My MPPT is ON 100% plus it maximises the available power by electronic wizardry. :roflmto:

My solars are only rated at 5.6 amps each so clearly the mppt is improving that claimed output.

Any mppt regulator is 25% more efficient simply because it charges constantly not by modulation. This is further improved by the ability to manipulate the voltage at the maximum power point for any given conditions.
IMG_0033-M.jpg

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Sep 3, 2012
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Hi
can you please satisfy my curiosity and advise what you use on the load output on your MPPT controller ( the bulb icon) -I thought this was for a night-time timing situation or can it be used for something else?
thanks:thumb:
 

Techno

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Mine feeds the 12 volt socket in the adjacent box , I fused it at 15 amps and mainly use it to feed my wifi hub.
The load terminals on this regulator are ON 24/7
 
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Thanks Andy
so the power is there when you require it and not being used all the time?

:thumb:

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stevec
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Techno and Ivor.....you alude to an MPPT controller but which one are you using? And will I have to use two panels in series to get the volts up or will it work ok on a single panel?
 

Techno

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It will work fine on one or two panels up to 300watts depending on whether you buy a 200watt or 300watt unit
It will work with 12 volt panels in series (2) but personally I have 3x100 so series is not an option. Mine works perfectly with 300 in parallel
It can also handle 24 volt panels

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stevec
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Thanks Techno, I was looking at the Tracer units with remote display but there is quite a hike between the 10A unit (ok for now) and the 20A unit (would be better for any later upgrade). You obviously have had no problem ordering from abroad. What was delivery time like? And was there any import fees other than the ParcelForce ones (or did this include taxes)?
 

Techno

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Tends to be up to 10 working days now as parcel force cause a few days delay
I collected in person at a depot and paid there to save time.

Btw IMHO the novelty of a remote display will wear off. Afterall there is nothing you can do about the amount of light and charge lol
It's nice to occasionally have a deek and the display on these mppt of our choosing is very good but I'd rather watch tv or come on here :D

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stevec
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Thanks for the info. I've just looked at Solar Energy Alliance website (they are close to me) and they do a competitively priced 140W kit. I may go down that route. They offer the Tracer MPPT.

I'm an engineer and I like looking at numbers. I've seen a charger with a built in data logger. Heaven! O.K so I must get out more!
 

pappajohn

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Parcel farce charge £8 just to process the item.

My onboard charger travelled around 3000 miles from Chicago to the UK port for less than £20......then parcel farce charged £8 to pay the import fees and deliver it 250 miles in the uk.
It appears PF pay the duty then you pay PF.
 

manda3000gt

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MPPT BOOST CONTROLLERS (maximum power point tracking);
Yes, they do work, assuming that you run your batteries down low enough, which you will hardly ever do if your system is set up right. My system runs in the top 15% of its range 95% of the time. The magic boost kicks in when the batteries are low and will accept more amps at a lower voltage. There is little or no boost at higher voltages and when the panels are hot. Also, the manufacturers will tell you that you can overload their controllers and they will limit the power and protect themselves. If you look at the meter on one of these, it will show boost even when it is at set point volts where the manufacturer’s specs say there is no boost, so just what is it doing; boosting or shutting the power off? It can’t be doing both at the same time! I have proven that these controllers play games with the input amps shown. If you take one out and replace it with a good non MPPT controller when the batteries are near full, you will see that the input amps change, while the output stays nearly the same. I have done this more than once. I even got one of the RV Solar dealers to do this and boy did he get upset, red in the face & started yelling at me, something I am sure he would deny now that he is on the boost band wagon. I tested the input & output of one of the best ones available with my Amprobe and when I multiplied the numbers to get watts, I found that the controller was losing about 10% in its electronics. It was definitely boosting the amps while lowering the volts, but that unit was advertised to be more than 98% efficient, not 90% as I measured. If you carefully read the reports on these controllers, you will realize that the magazines never do comparison testing side by side with other brands and independent metering. They simply report what the meter on the charge controller shows as if it is gospel. The whole story is suspect and when you look around on the discussion forums; people have backed off from those huge claims and are now being more realistic. Of course there is another new manufacturer who is making up to 40% boost claims, but where he found this energy that nobody knows about is not explained. There are those who don’t believe in MPPT at all, but they are in a small minority. My background was in the lighting business, where certified independent test reports were the norm, so that is what I expect to see. There doesn’t seem to be any such thing in the solar business. I’m just not convinced that these controllers are worth two or three times as much money. I know, the small two stage units don’t cost that much, but they don’t work. I have replaced several of them with non-boosting three stage units and the systems had more power afterward, not less. The “experts” don’t want to believe this, but the people that I have done this for would tell you the truth. Buy a three stage boost unit if you can afford it, just don’t expect any ”25% or more” extra power and do not overload it so that it shuts your power off. Just read the directions. Somewhere around 5 or 10 % average daily increase is more like it and you are going to get that much extra by running big wires. Last, don’t completely believe the latest “trick” about fixing voltage drop problems in a system by running 24V down from the roof in small wires and then transforming down to 12V in the controller. All transformers (including electronic ones) have an efficiency loss and even the MPPT circuitry is not 100% efficient. You gain by running 24V & then lose by running it through a transformer. Last, the boost comes from using excess volts put out by the solar panels and turning it into amps. If you don’t install great big wires so that voltage is actually getting to the controller, then you are wasting the extra money spent on the MPPT controller. Morningstar is recommending that you design for only a 2% loss, panels to the controller and that means even bigger wires when using MPPT. The older recommendation (that the solar “professionals” have mostly ignored) was 3%. The dealers who tell you that MPPT will make up for the voltage loss in the wiring are lying to you. Without the voltage, MPPT cannot work. You can use higher voltage, lower amperage panels and get a bit more power with MPPT. This does work because at a higher voltage, you will have less voltage drop before the controller. However, 100 watt panels put out a max of 100 watts. When the company makes outrageous boost claims, they are talking about boosting the amps from panels that put out lower amps than other standard voltage panels, not the watts. They use this as a marketing tool. You need to do some serious comparison shopping before you decide if their system is worth the price. You need to compare other systems using standard voltage panels and big enough wires for watts per dollar into the batteries. I have seen my meter showing 340 watts for short periods of time from my ten year old 345 watts of panels on cool mornings with my PWM Morningstar Tristar that is not MPPT.

Taken from Handy Bob Solar
 

manda3000gt

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If the charge controller meter is displaying purely the input amps being generated by the panels (21.6) would the fact that 1.3kw being drawn from the inverter have no bearing, I would not think it a net display as in a battery monitor.

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Gorse Hill

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Techno what has been written above seems creditable/plausible to me, please explain why you don't think so
 

Techno

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Yes the regulator is responding to the load on the battery by producing the maximum that it can glean, the display does not reflect the voltage at the battery which is at this point 11.9 . There' nowt wrong with your quote apart from its length :LOL:
 
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