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What is the best cheapest mppt charge controller

OK so if I hooked 2 together would give me 4 sets of two then I could use say a 30 or 50 amp controller.
or should I just make them all in series
 
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OK so I found this controller at Bougerv its an mppt 40 amp 12/24 for $119 and I guess its made by srne solar Do you think that this would handel what I have. sorry totally new at this. Or could someone suggest a good mppt around $150 40 to 60 amp
Bougerv.com
 
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>>
System voltage:12V/24V
Zero load loss：<10mA
Battery voltage：9V~32V
Maximum PV open circuit voltage：92V(25℃)；100V
Maximum power point voltage range：（Battery voltage +2V） ～ 72V
Rated charging current：40A
>>>
The key number is max pv open circuit voltage (Voc) for compatibility (can NEVER exceed this). And the MPPT range ~72v.

You want to arrange your panels in series to match those.
With your Voc 23.8, you can do up to 3 in series. But that does not work well with 8 panels because you cannot do 3S + 3S + 2S. So 2S4P is has to pretty much be.

So pair up your panels into 4 strings of 2 panels in series. Then you connect them together in parallel.

What connectors are on your panels? Amazon has some 4:1 Y cables for around $15 that make is really easy to combine strings in parallel.

If you have MC4 connectors, these would be a good choice:
https://www.amazon.com/DSOLA-Connector-Extension-Parallel-Connectors/dp/B0833ZMKWD/
 
OK cool thanks! The wires on the panels were cut so I will need to add new ones. thanks for the link I was looking for something like that.
I was going to get 10 awg wire. the panels will be about 25 feet away from the controller.
 
Ok cool. I just found out that the controller I was looking at won't do lead acid batteries. So I am on the hunt for a good mppt again
 
Just chiming in, I am looking for safe affordable high amp mppt too.

I checked the 100A model of OOYCYOO MPPT and read this review

1625708728510.jpeg

Personally, given that the sun moves and I’m going to have multiple panels, and shading is already something to design around…

Combining multiple MPPT of smaller ampere rating is a strategy that appeals most to me. Easier to cool I reckon..

By smaller I mean 60 Ampere charging or less.

Multiple 30 Ampere or 40 Ampere MPPT combined might run cooler and be less of a fire risk.

Because let’s be honest..
100A means a Lot of Joule Heating.
 
Yea I know now that I can go down to 30 to 60 I would like to stay around 50.
 
Chip said:
Ok so how big of charge controller would I need.
Click to expand...
If you wanted the equivalent 12 volt wattage with a 24 volt battery, you would need a 24 volt 50 amp SCC, rather than a 12 volt 100 amp SCC (both are 1200 watts).

Your battery size and useage would be useful in the calculation as well. How big is your battery (and chemistry), how many watts to you use per day, and what is the maximum load on your system all at once?

Your panels will produce no more than 512 watts, or less than 40 amps at 12v. A 50 amp, 24 volt system would allow you to add about 650 additional watts, and a 50 amp 48 volt system would let you charge at 2400 watts, or 1880w more than 12 volt at the same amperage.

If you are looking for over 1000w charging, a 24v or 48v system is absolutely the way to go; especially if you want an AC inverter over 2000 watts. A 3k watt inverter uses more than 250 amps at 12 volts, and requires a massive, and expensive, copper cable. At 24 volts it uses 125 amps, and 48v uses a measily 63 amps which can be run with a much smaller cable. My suggestion is if you ever need more than 2000 watts, to go with a higher than 12 volt system.

It sounds like you want to leave room for improvement, and a high(er) voltage system leaves that room. A 50 amp, 24 volt (1200 watt), or 30-50 amp 48 volt(1440-2400 watt), SCC would meet you needs for adding more panels later. A bigger, larger than necessary, SCC is never a bad idea.

I have personal experience with a Victron SCC (it's the best, IMHO), and I have heard that Midnite solar is a quality brand as well. There are other brands of all-in-one units that are good too, but I don't have much experience with them.

I would go with this for a 24 volt system.


Or this for a 48 volt.


This is also a versatile version that takes up to 150 volts solar, and puts out 45 amps (540 watts @12v, 1080 @ 24v, 1620w @ 36v, or 2160w @ 48v). It also comes in a 60 and 70 amp model.

 
FLA batteries have a chance to get nicad but was told that fla was safer
 
i use victron bluesolar mppt and think it’s a good deal for what it is.

about 2.5-3.5 Watts of Charging per USD at 24 Volt system. (2.5-3.5 WoC/USD@24Vbatt)

smartsolar = has bluetooth
bluesolar = has no bluetooth

i use bluesolar because preference to interface via wired data cable and ability to prevent tampering from any bluetooth access, once configured.

i only expect 85% of the listed charge current in normal circumstances based on my experience. the heatsink is very effective on the models that do have them. if i want to run the heatsink cool without fan then configure for ~75% charge current.

definitely echo what @A.Justice mentioned: 24V or 48V system voltage to design around. avoid 12V if seeking cost optimized MPPT solar charge controller.

good luck!
 

Does will have a link for these connectors​

25Pairs / 50PCS Solar Connectors - Male & Female IP67 Waterproof Connector​


And for the ones that go in the back of the panel (Cable Gland) I think it is a 3/4 hole
 
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IMO you are overcomplicating things. With the lower wattage panels you have I would just stick to a 12v system so that you can use pretty much anything on the DC side for output to your loads. You can use two cheaper MPPT controllers if needed and split the panels into two groups to avoid the high current issue. Get your feet wet with what you have to work with and if it all works out then down the road you can change out parts as needed. Prices and tech changes each year. I ran an EPSolar 4210 for a couple of years in the RV and only swapped it for a Rover 40 because I wanted to play around with the data feed. After 6 years I'm swapping the 4 Fullriver 224-6's for Li as they have aged to where they are at about 75-80% of cap.

On the other hand, if you have a large budget throw everything away and buy all new top end equipment ;)
 
OK I checked and the other scc by Bougerv does work with lead-acid and user select the ad that I was reading was wrong.
But I bought an EPEVER 40A MPPT 4210an. I think I have almost everything I need to start. I did get a 24 volt windmill
and bought as much as I could from will. By the way thumbs up to will on his last video(y)

​

 
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Chip said:
OK so I found this controller at Bougerv its an mppt 40 amp 12/24 for $119 and I guess its made by srne solar Do you think that this would handel what I have. sorry totally new at this. Or could someone suggest a good mppt around $150 40 to 60 amp
Bougerv.com
Click to expand...

It works, it's nothing special. Get the Bluetooth if you like. Same controller Renogy sells.

Specifications

  • Rated Battery Current: 40A
  • Rated Load Current: 20A
  • Max. PV Input Short Current: 50A
  • Max. Battery Voltage: 32V
  • Max Solar Input Voltage: 100VDC
  • Charge circuit voltage drop: ≤ 0.26V
  • Discharge Circuit Voltage drop: ≤ 0.15V
  • Working Temperature: -35°C to +45°C
  • Max Terminal Size: 8AWG
  • Rated Load Current: 10% to 90% NC
  • Overall Dimension: 9.37 x 6.81 x 2.85 in
  • Net Weight: 4.41 lb
 
Chip said:
OK I checked and the other scc by Bougerv does work with lead-acid and user select the ad that I was reading was wrong.
But I bought an EPEVER 40A MPPT 4210an. I think I have almost everything I need to start. I did get a 24 volt windmill
and bought as much as I could from will. By the way thumbs up to will on his last video(y)

​

Click to expand...
I picked the same epever 40 after reading a bunch and the will prowse video settled it. I also bought an “opened box” and bought it for cheap. Worked well right out of the box

My goals were to not buy cheap but get a quality lower-priced product mppt (to upgrade the P30L pwm I’ve run a few years now) that permits 24 or 48V input to 12V batteries.

I think you made a good choice- granted I’m only in a few months now, but it’s been great. I ‘recover’ daily a bit faster than the pwm did. It seems to equalize weekly just fine. Not sure it’s any better than pwm on cloudy days but that’s an observation not a complaint.
You keep mentioning NiCad- I’m assuming that’s a mistake and you mean Lithium chemistry????

I would have no problem running lead acid. I do myself. Lead acid batteries will be disappointing if you run them deep discharged- you both need to have enough watts solar input to get them 13.x daily and enough battery to last at least three days of cloudy weather.

I just had three cloudy rainy days in a row. Yesterday I was 12.1 in the morning, this morning 12.3. Those are fairly low imho. But sun today and 6:30am after making coffee I’m up to 12.6 already. If I was to watch all day I’d bet by noon I’d be reading 14-15V cuz the epever always seems to sock it hard after days of low input. And you need to do that because the battery volts of lead acid will ‘settle’ 5-10% lower after charging input ceases. Basically you need to exceed the need so you can be mostly at “float” an hour or two before sunset for best battery output- and life

If you drag down regularly and stay there long, lead acid won’t have good lifespans. By low I mean 12.1 to 11.9. If you’re hitting say 11.4 everyday that’s where people’s two year life expectancy comes from. So run enough panel to really sock it to the batteries when needed. I just looked again. Batteries are showing 13.1V and 6.9A (only 200W ‘see’ the sun right now; in a few hours those and another 200W will have sun exposure. By 1pm I’ll be back to full sun on 200W. At some point here I need to remount the other two 100W panels; I was just expirementing when I added the electric fridge with two series pairs facing different compass directions and it’s working so well I haven’t been motivated to do it)

my goal is to never be below 12.3 and I achieve that most of the time- all the time without rainy days.

There’s a bunch of good lead acid threads on this forum btw. Don’t swallow the lead battery bashing; yes there’s new tech batteries but the old tech didn’t turn to junk and stop working when they came out with the new stuff.
 
OK thanks 12voltinstalls. and yes I am sure about being ni-cad they are for Honda Civic and other Hybrid cars.
 
MisterSandals said:
Yes, easily. You will need to have at least 2 in series to get above 24v.
Click to expand...
With just 2 in series, you will not have enough headroom to be comfortable at a 24V battery under hot weather.
with 4 in series you come to high voltage limitation that leads to more expensive stuff.
The best deal would have been 3S2P, even if you don't use two of your 8 panels you will run better under the line.

If you can, just with one panel more run 3S3P that would be the very best.

You can then run with a 100V 25-40A controller, these are the best value for the bang.
 
Chip said:
OK thanks 12voltinstalls. and yes I am sure about being ni-cad they are for Honda Civic and other Hybrid cars.
Click to expand...
No modern hybrid uses nicad.
All are based on lithium.
Nicad is even banned in the EU except for replacement cells, since cadmium is quite toxic.
 
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