MPPT controller - Please recommend a cheap and good one- if such exists,

[Abel Seaman 19]

Hi all

I am wanting to bump up my solar on my Trailer yacht to 70 watts nominal. I don't have huge electrical installation and this amount will improve the current setup to meet my needs. (pun intended)

At present i have a cheap PWM unit with my smaller panel, but want the efficiency of a MPPT and also some sort of display would be nice. I don't want to pay victron prices. Trademe etc has lots of  cheap controllers  claiming to be MPPT, but are they in fact and are any of them any good?

Thanks

[whitepointer 34]

I have a tracer, from AA solar, 8 yrs old and still works well, burnsco do Renogy which seem well priced

[Ex Machina 390]

2 hours ago, Abel Seaman said:

Hi all

I am wanting to bump up my solar on my Trailer yacht to 70 watts nominal. I don't have huge electrical installation and this amount will improve the current setup to meet my needs. (pun intended)

At present i have a cheap PWM unit with my smaller panel, but want the efficiency of a MPPT and also some sort of display would be nice. I don't want to pay victron prices. Trademe etc has lots of  cheap controllers  claiming to be MPPT, but are they in fact and are any of them any good?

Thanks

 Victron has very cheap units it’s if you get them from here 

https://victronenergy.co.nz/

I will be putting a Bluetooth job on my TY with LifePo4 battery soonish . I like the Bluetooth to smart phone function cause I can tuck it away near the battery box out Of sight . You get what you pay for with solar gear 

[aardvarkash10 1,103]

The old car truism is that you can have cheap, fast and good - pick any two.  I'm guessing it holds true here too.

we have a 130W system utilising the 20A version of this controller from this supplier.  Fit and forget.  Reasonably programmable as long as you don't have some weird multi-chemistry battery bank.  

[Island Time 1,293]

Cheap and good is a contradiction. Get a victron Bluetooth MPPT controller. Best programmability, best output. The others, including Tracer, wont give you the same output or the same battery life as a victon. They start at $200 - how much are your batts worth??

[Abel Seaman 19]

4 hours ago, aardvarkash10 said:

The old car truism is that you can have cheap, fast and good - pick any two.  I'm guessing it holds true here too.

we have a 130W system utilising the 20A version of this controller from this supplier.  Fit and forget.  Reasonably programmable as long as you don't have some weird multi-chemistry battery bank.  

Thanks very much for that. That model is one of the ones  that i was looking at so that is very useful feedback.

Back story:

If i had a fully wired and instrumented keeler with multiple batteries, i would not hesitate to spring for the best, but I have a simple, low value (but dear to me) boat with a single deep cycle battery that doubles as starter battery for my electric start, long shaft outboard. 

Starting the engine with the pull cord is not difficult so there is no point having a separate starting battery. Electric start is nice but the real reason i went for it was that for an electric start honda the charging coil (magneto?) delivers twice the amps to the battery as compared to the same motor supplied with pull start only. It actually does return a useful amount of charge to the battery but who wants their motor running more than is essential?

 

[idlerboat 116]

I have a range of charge controllers running.

From non descript early Chinese PWMs to a Victron in my Van. 

I like Victron stuff and have installed a bit of it , but the price of the bigger capacity units is more than I could justify for the benefits. (even if the display/controller unit is great fun to watch ). I think you will find that although based in the Netherlands , the bulk of their gear is manufactured in either India or China. (Like most).

My big bank at home 5K of panels running into 3 banks of 2 volt AGMS (@12 volts a bank) is running three of the largest EPEVER controllers. These controllers can be programmed through downloadable on line software. It is a bit of an effort to start with but once sorted you can set the charge parameters to exactly what your batteries manufacturers spec sheets recommend. You can use their add on bluetooth unit for control or monitoring if you want but there is a heap of apps and doohickeys that you can add in later from elsewhere  , if you want continuous monitoring and/ or logging. (I just run a RS28 lead to my laptop to check from time to time that all is happy and do my mental arithmetic of my kwh price compared to running mains  )

For best overal value I would go for a suitable newer model EPEVER , probably from aliexpress or similar , but its worth looking around. 

My best advice for battery longevity is try not to discharge them !! (much)  My boats AGMs are just starting to fail, the youngest is 10 years old. 

[waikiore 477]

I have a basic Victron not bluetooth and had no problems with remarkable efficiency in summer.

[bigal.nz 61]

+1 Victron

 

[mattm 106]

I like the Victron stuff to, but understand not wanting to spend so much in your circumstances.

 Just remember, in a 12v circuit, an mppt controller does not give its best efficiency (any/much greater than a pwm??) unless you have 2 x 12v panels in series, or a 24v panel. 

From a victron manual:

Recommended number of cells for highest controller efficiency: 72 (2x 12V panel in series or 1x 24V panel).

 

[Island Time 1,293]

1 hour ago, mattm said:

I like the Victron stuff to, but understand not wanting to spend so much in your circumstances.

 Just remember, in a 12v circuit, an mppt controller does not give its best efficiency (any/much greater than a pwm??) unless you have 2 x 12v panels in series, or a 24v panel. 

From a victron manual:

Recommended number of cells for highest controller efficiency: 72 (2x 12V panel in series or 1x 24V panel).

 

Hmm, Sorry Mattm, but I dont agree with that. Sure, the BEST POSSIBLE performance is as above (2x12 or a 24v panel). Improvments between PWM and MPPT can be as much as 40% in that configuration, but for a single panel install I've still seen improvements of over 25%.

[Abel Seaman 19]

Well I followed Aardvarkash10' suggestion and bought an EPEVER MPPT controller. It does seem like the cost /quality point i was looking for. Actually it arrived today and seems to be a solid bit of gear.

My next question regards series or parallel. I already have a 20 watt panel which seems to be working just fine so i would like to continue using it and add a 60-80 watt panel as well. 

Series or Parallel? 

Thanks

 

[grant 44]

On 11/08/2022 at 9:12 PM, Abel Seaman said:

Well I followed Aardvarkash10' suggestion and bought an EPEVER MPPT controller. It does seem like the cost /quality point i was looking for. Actually it arrived today and seems to be a solid bit of gear.

My next question regards series or parallel. I already have a 20 watt panel which seems to be working just fine so i would like to continue using it and add a 60-80 watt panel as well. 

Series or Parallel? 

Thanks

 

if you want them in series it would be better to have matching panels so would suggest you parallel them

 

[Frank 166]

On 11/08/2022 at 9:12 PM, Abel Seaman said:

Well I followed Aardvarkash10' suggestion and bought an EPEVER MPPT controller. It does seem like the cost /quality point i was looking for. Actually it arrived today and seems to be a solid bit of gear.

My next question regards series or parallel. I already have a 20 watt panel which seems to be working just fine so i would like to continue using it and add a 60-80 watt panel as well. 

Series or Parallel? 

Thanks

 

I'm at the tail end of a campervan project with two panels on the roof, the folks at Half Moon Bay Electrical strongly recommended putting them in series. Feedback they received from customers who had made a change from Parallel to series was that it made a big difference. It was something to do with getting more bang for your buck when the sun was low at either end of the day (don't shoot the messenger, this is just what they advised

[Island Time 1,293]

The parallel or series answer is "it depends". Yes, you get more power from series in full sun. However when partially shaded, the whole array is severely effected.  Parallel arrays are effected less by partially shading of part of the array, as the unshaded panels still produce full output. Yachts often have partial shading - masts, rigging etc.

[TimB 7]

 

Yachts often have partial shading - masts, rigging etc.

So do caravans, when parked near trees.....how do I know.....?  Mine are two x 150W in parallel through an epever 40A controller. Max I have seen is 20A.

 

cheers Tb