What's the Difference Between a $150 and $600 MPPT Charge Controller? The MakeSkyBlue MPPT

If you go looking for solar charge controllers, there’s a wide range of hardware out there, for a very wide range of price tags.  My office normally runs the main array on a $600 Midnite Classic 200 - but I’ve spent some time recently running my main array on a $130 MakeSkyBlue MPPT unit.

This is a companion discussion topic for the original entry at https://www.sevarg.net/2018/05/27/whats-difference-between-150-and-600/

(Comments from Blogger)

2018-05-27 by Megabytephreak

I would not consider 200V caps and FETs on a 190V rated unit to be conservative, I would consider it quite aggressive. Especially in a switch mode power supply, which is essentially what this is. Inductive kicks can be nasty. I might consider it “ok” at a 150 volt rating. I’d probably want to see at least a 250V rating, preferably 300V on the MOSFETs.

I’m also not a fan of heatsinking to the case as is done here. I it looks to me like a steel case, and the thermal conductivity on steel is not very good. With aluminum it would be OK.

2018-05-27 by Russell Graves

I’m pretty sure it’s an aluminum case - though I’ll verify. It felt like aluminum to me, though.

I agree that the rating is close, but it’s conservative for Chinese ratings where I’ve seen “max do not exceed” voltage listed as the rated voltage for items. Also, a 190Voc max means the panels will normally be operating below 150V. The concern is not blowing the controller up in the winter. Typically I see no more then 160V on my 4 panels, and I run around 115V. But the headroom is nice, and I wouldn’t want to use a 150V rated controller on my array.

2018-05-29 by Russell Graves

The case is definitely non-ferrous, so I’m assuming aluminum.

2018-07-06 by ‘yes’

https://user-images.githubusercontent.com/36188081/42123928-00e2cc42-7c52-11e8-8f02-82bc9d762192.jpg my version of make sky like, I noticed the error of tracking below 60v. I developed my firmware. Implementing CAN for multi device synchronization. ��

2018-07-07 by Russell Graves

Do you have your firmware posted anywhere?

2018-08-03 by Unknown

Hi Yes…
Can you give any more details/info about your modifications/code/project?

2018-08-09 by Unknown

Hi, my project is still on development stage, though it’s working well, I disabled auto detect battery feature, so users use 12v or 24 or 36v or 48v,you set your battery cut off limits yourself. I changed from 8bit pic to 16bit pic for more reliable system. Will be available as soon as I complete the project.

2018-08-21 by Lex

I really appreciate the detailed breakdown. I think you were a little hard on this unit though, considering price point and capacity, seems a bit unfair to compare directly to a unit 5x the cost. I bought one aware of the limitations & worked within them, enabling me to build a system out until I can upgrade to a long term solution. A lot of budget limited DIY solar enthusiasts develop their systems this way, working toward a final configuration goal. I think this unit is useful in that regard. I’ve fleshed out my system to just about final envisioned config, most recent purchase was 5Kw of Johnson Controls Lithium, and this little MakeSyBlue is holding its own so far…my next purchase? Midnite Solar Classic 200! at which point this little $140 unit will be put out to pasture with much gratitude…

2018-08-21 by Russell Graves

I understand that I was comparing with a far more capable unit, but from the context of solar charging and battery management/longevity, the things I complained about matter.

Randomly missing the maximum power point is just unacceptable in a solar charge controller - I hate to say “You have one job, MPPT controller…” - but that MPPT bit is key to why we use them, and if it’s not operating an array efficiently, and not charging batteries as a result, that’s a big problem. I assume it’s a firmware issue, but it wasn’t a one-off problem. I just got tired of documenting it. Having to power cycle my panels every day or two is unacceptable in a charge controller.

The quirky “Everything is a multiple of 12V” voltage setting is also a problem - be careful that you don’t trip across that with your lithium bank.

And I wouldn’t have minded the absorb/float inversion so much if it gave me options to do something different. A simple timer would be nicer than the behavior it has for complex systems, though the behavior exhibited is likely fine for a system that only has one charge controller. Except… these are often sold as pairs.

Mechanically and electrically, I’m happy with the unit. The firmware is just a mess, though. I suppose with enough work, one could reverse engineer it and put something competent on, but that’s more work than I feel like taking on at the moment.

For a DIY build over time, though, I think your approach is somewhat wasteful. Even if you’re upgrading things as you go, spending the money on the good core components up front is worth it. A Classic will run a 12V system just as well as a 48V system, so you can buy one of those early. And with the WbJr shunt, it’ll treat your battery bank far better than a blindly charging controller with no settings you can adjust.

2018-08-21 by Lex

Yeah, I went up to 14s to avoid that. You would think MSB would revisit the algorithm and release a V2 with revised firmware, the unit is already popular, seems a small investment to eliminate the quirkiness.

2018-09-07 by Lex

A little follow up… So I purchased 5Kw of very nice, robust, Johnson Controls NMC lithium assemblies, altered them from 12s to 13s, and deployed them in my compact solar enclosure. Everything seemed to be peachy, until I actually sat through a morning recharge cycle observing my 60A MSB charge controller’s behavior as my 3Kw array gradually came into sun exposure. I had the following settings. D01:13.3, D02:13.3, D03:10, D04:01.

2018-09-07 by Lex

continued… As I watched the charge process, all seemed well, current varying between 12-20A, voltage steadily climbing from 48 through 50…51…52…53…54! it ignored the 13.3 (53.3v) max voltage setting, and was happily taking my lithium pack towards certain death…I promptly switched off my panels and reactivated my Gel battery bank and inverter internal controller.

2018-09-07 by Lex

…I read a youtube comment thread about a guy experiencing overcharging with this unit, he claims removing one of the double PV input wires eliminated the problem. I am curious as to whether you noted anything on the input trace paths that would support that behaviour?
(btw, this just tech curiosity now, I’m sufficiently scared into getting a proper controller. I’m looking for a low profile, small form factor unit now, the MidNite would take up too much space in my enclosure. Any suggestions?)

2018-09-07 by Russell Graves

Thanks for the report - that’s properly terrifying.

I ran both contacts - I expect they’re ganged together but haven’t actually verified. Presumably, it was just one of the random glitches this unit is prone to.

I’m not aware of any good low profile/small form factor units. You’d have to look around. Most of the legitimate units are larger. On the other hand, I’ve literally never seen my Classic do anything unexpected with voltage…

2018-11-10 by Unknown

Would a pwm be ok for voc 45.8 vmp 37.4 I was going to use the one u talked about but now I dont know I have 25 330 watt panels and 4 144 amp hour 12volt amg batt so far and how many batt u think for the 25 panels I could add more panels if needed I have 60 of them got good deal have very little money to speed on charge controller and have so many panels th for your review and time

2018-11-10 by Unknown

The panels r boviet model bvm6612p 330 h need something cheap to run them on I am a poor hillbilly that loves God and and the earth that he made have kids also so very hard to save any money ty for your time

2018-11-11 by Russell Graves

I’m pretty sure you should sell a few panels and buy a decent charge controller. This won’t handle your panel count, and probably shouldn’t be trusted with a large system.

2018-11-15 by Unknown

Helpful article! Better than anything “mppt” cheaper.

2018-11-15 by Unknown

A very nice and detailed review. I have just ordered a 30 amp V117. Which version is your controller?
They claim hardware and software changes in V117.
I might have to see how many FET’s it has on the backside. Maybe it’s possible to upgrade it to higher output?

I bought mine here:

2018-12-10 by solar-interst

Hi, What version firmware is your review based on ? I just read a bit about V117 - but the AliExpress webpage says circuit board changed between V116 & V117. That might mean V116 is highest possible for previous designs. I ordered 30A unit from official US MakeSkyBlue on eBay a week ago - but I think it will be OLDER version board & Firmware. Wish I had seen the Official MakeSkyBlue webpage on AliExpress earlier ! Total price approx same as eBay. BTW: Thank you for excellent review !

2018-12-11 by solar-interst

What is Firmware version # your review is based on ?

2018-12-11 by Russell Graves

I don’t see any way to extract the firmware version from the unit - how are you determining what firmware revision yours is?

2018-12-11 by solar-interst

I just received 30A model. When first power up, number on lower right corner of LCD = firmware version. Mine says 113. I should have ordered via AliExpress - because there you can choose V116 or V117. According to the MakeSkyBlue page, the circuit board changed between V116 & V117.

2018-12-11 by Russell Graves

Ah, mine shows 113 very briefly.

2018-12-11 by Russell Graves

However, my board also says MakeSkyBlue in the silkscreen - so perhaps I have a very old, legitimate product.

2018-12-11 by solar-interst

Thank You ! but … BUMMER for me. I was hoping that you had an older version, and that maybe V113 was an update. This means I will see the exact same problems you detailed. I read on another website that a guy built a monitoring circuti to reboot his MakeSkyBlue MPPT every time the output voltage stayed at below 40 volts for 10 minutes (or something similar). He said this helped lots.

2018-12-11 by solar-interst

Mine also says MakeSkyBlue in silkscreen. Looks exactly like yours - except missing inductors L1 (but HAS the nearby SMD stuffed)& L2 (& MISSING surrounding SMD), and opto U4. Appears that 2 of the 3 pairs of power FETS are installed. Interesting - because this is ‘30A’ model, and yours is ‘60A’. From your original review, I guessed 20Amp per pair. I did not remove board to see if same FETS. Maybe mine are lower current rating. Or maybe they build 30A & 40A units same.

2018-12-11 by solar-interst

Did you ever dig deeper into that pin header ? Programming header ?

2018-12-11 by solar-interst

I have emailed MakeSkyBlue some questions tonight - and got very fast replies ! In one reply they point out 160V open circuit limit for PV array into the MPPT. You mentioned 190V and that your array sometimes shows 160-170V. I justed looked at the manual V1.2 that came with my 30A unit, and page 1 shows the same 160V max that they mentioned. Did your unit documentation say 190V is OK ?

2018-12-11 by solar-interst

The MakeSkyBlue people also state that they ‘solved that problem’ -when I asked about another reviewer who said he resolved by building a monitoring circuit to reset MPPT after logging less than 40V for 10 minutes (or something like that) - and which sounds similar to the one you described. It happened frequently. I don’t know what firmware version that reviewer had OR what firmware version supposedly fixed it.

2018-12-11 by Russell Graves

I have not. I’m sure there’s something interesting on it, but I have more projects than time, and a somewhat flakey backup solar controller RE project is really, really far down the list.

2018-12-11 by Russell Graves

The sales pages certainly did. It seems the newer ones have fixed that. Do a search for 190V 60A MPPT and you’ll find plenty advertising that.

2019-01-10 by Unknown

It says right at startup for the first few seconds. It will show Amps and Version. Mine shows “30 117” for 30Amp and V117

2019-01-31 by ‘yes’

Have you checked libresolar project with 32bit microcontroller? It’s an open source 20a mppt featuring advanced communication protocols that makeskyblue lacks, I currently ported the code to my 40a MPPT hardware, he used synchronous buck which is far more efficiency than makeskyblue which uses asynchronous buck, so building my libresolar based mppt is cheaper, I can do more quantity and use in my solar projects too . You can adjust any parameter through USB or CAN , or even serial port . So diy is never wasted times or resources . I am electronic enthusiast and developer too . I will post my comparison with makeskyblue and other popular MPPT after I complete the project, stay tuned .

2019-01-31 by ‘yes’

Link to the Proteus PCB 3d image of the MPPT charger controller .


2019-01-31 by Russell Graves

I’m aware of their work, but I’m not aware of anywhere selling units, and doing low volume production for a backup charge controller exceeds my interest (and likely cost) for a basic unit. If you happen to know where I can obtain one, I’m certainly interested in messing with it, and I’ve considered building a few, but… haven’t gotten a round tuit yet.

2019-03-29 by John Carter

For smaller systems (less than 40 amps) the EPEver/EPSolar Tracer MPPT series works and have remote monitoring/control ability (RS485 plus wifi/ble add-ons). I have two 3210 (30A) and one 4210A (40A) and I don’t exceed about 90% of the ratings (27A output from a 30A unit) although I limit that to 80% of the solar input voltage (80V on 100V rated input). So far, they’ve been reliable. Not the fastest in finding the MPP but they do find it and they are able to modulate the power well - no sudden jump in battery voltage when there’s a 10 amp change in battery load.
I’m exploring a 60A MakeSkyBlue unit that works but the displayed voltages are off by 0.2 to 0.25 volts compared to the meter I just checked at 10.00 volts with an AD584 voltage reference. (need to get the MSB version number). I’m using 540Ah of 12HX330FR AGM’s that would be OK with the 0.1V settings - although float is spec’d at 13.65V - something the Tracer 3210A can reach and hold. Actually being at 13.60 or 13.70 would be OK but being off by 0.2V or more is not a good thing for any battery chemistry.
I’ll try setting the MSB to the values I want, based on my calibrated DC voltmeter, and then see if the MSB can maintain those settings.

2019-04-02 by Unknown

I have the 30A model V117 and far it performs well. I was wandering if it could be opgraded to bigger model?
They seem very simular. Maby its only missing a mosfet and a change of firmware?

Have anyone compared models?

2019-04-07 by John Carter

My 60A MakeSkyBlue MPPT controller has firmware 113. The latest firmware version is 118 and is advertised as using actual voltages so perhaps they have listened to their customers.
I have a 20A MSB kit (something I can build into a shed wall) on the way, floating somewhere between China and the US.
When it arrives, we’ll see which firmware it has and how much its operation differs from version 113.

2019-04-07 by Russell Graves

Let me know how it works. If it’s significantly improved, I might pick one up to mess with.

2019-04-07 by John Carter

From the author’s comments, the 60A unit has three sets of FET, diode, toroid and capacitor with each set apparently handling 20A of the load. The considerations for modifying an existing unit for higher power would include whether there is sufficient drive power to handle another buck regulator and whether the board traces can handle the increased current. The only firmware consideration would be how the processor determines overcurrent on the input or output (probably different shunts for each range). If the PCB traces can handle the extra current and the heat sink is adequate, you might be able to parallel the current shunts with additional wire to change their values or perhaps see if there are any voltage divider resistors in between the shunt and the processor’s ADC and adjust them. That would be a hack job but it’s easier than modifying firmware that no one seems to have a copy of. Having an English copy of the source code for the firmware with good notes in it would be ideal :wink: I’m not familiar with the TI chip in the MakeSkyBlue and not really interested in learning another microprocessor. I’m 70+ and still interested in almost everything electronic but I don’t see a need to subject myself to the torture of learning yet another chip family.

2019-04-20 by John Carter

My MSB 20A kit has firmware version 114. Within its 20A limits, it does work, just occasionally getting “stuck” at some specific solar input voltage - this one seems to like 23.76 volts. Sometimes disconnecting and reconnecting the solar input works. Other times it seems to be related to the volts/amps ratio, as using an adjustable power supply set to 30 volts the MSB will “stick” around 24 volts on the input if the solar input is limited to 1 amp but can find the MPPT point if the solar input can supply 3 amps.
If it had the newer firmware, it might be OK but as it is I’ll be vary careful about where I use it - charging the 12 volt battery that runs the winch in the shed isn’t critical so maybe use the MSB there?

2019-04-20 by John Carter

The 7 pin connector on the MSB board is JTAG.

Thanks to the picture here:

and the TSM320 F28027 datasheet:

The pins on the unused 7 pin connector on the MakeSkyBlue MPPT solar controller boards are JTAG.

pin 1 - [3.3V]

pin 2 - [8mv]

pin 3 - [15mv] TCK, XCLKIN, GPIO38 (CPU pin 23)

pin 4 - [0, 3.3V - this is the BLNK LED] TDO, GPIO37 (CPU pin 22)

pin 5 - [14mv] TMS, GPIO36 (CPU pin 21)

pin 6 - [3.3V] TDI, GPIO35 (CPU pin 20)

pin 7 - [4mv]

For the measurements in [], I used the 20A MakeSkyBlue kit because it’s not yet in a case and the terminals are easy to access.
Voltages are referenced to the Bat - terminal.

Pin 1 is the pin on the end that is at 3.3 volts. On the 20A board, it’s the pin next to the J1 designation on the board.

2019-04-21 by Russell Graves

Nice, thanks!

Any chance you’ve had luck pulling the firmware?

2019-05-09 by Solar Search

There were some reviews of these with pictures on Amazon showing they caught on fire or melted. Somehow they removed their old listings on Amazon and started new listings and were able to remove the bad reviews. I think they called it a new version and got away with it. Although my V113 unit is not getting too hot, I am worried… If my unit does malfunction in the future it can catch fire. It does charge up to 16 volts most days. It is cooking my batteries and I have re-start it all the time.

2019-05-09 by Unknown

I have had a MSB 30A V117 for a while and so far it works fine with 2x250W panels and 24 volt AGM power wall.
I have gotten 4 new 310W panels and changing wall to 48 volt. The new setup will be pushing the 30A model to its limits.

My plan was to buy the 30A model and hack it into a 60Am but have not had the time yet. The PCB seems the same and I think its only a matter of missing components and firmware.

Speaking of firmware: I had some questions for MSB and they are very fast to reply. As you can see below it CAN be updated (newer version og maby even 30A to 60A)?? :smiley:

My questions:

Some time ago I bought a 30A model V117 from you. I am quite happy with it and I am planing to buy one more, but I have a few questions:

- What is the difference from V117 to V118?
- Will V117 and V118 work together in parallel?
- Can I upgrade firmware from V117 to V118?

MSB Reply:

I’m so happy to received your question.

-V117 support to work together with V118 in parallel.
-V117 also support to upgrade from V117 to V118.
This process need to use our sepcail upgrade tool (Value USD$15) as the attach picture.

The difference between version 118 and 117

1. The V118 use new updated motherboard different from V117
2.The V118 expand ranges to support more battery types including sealed lead acid ,vented gel nicd flooded and lithium lifepo4 etc.
3.The V118 will display total floating value more directly
4.The V118 had updated design circuit diagram to eliminate some comment error like E74 and Load Fault Reboot
5.The V118 version much better for OU+/OU- to control loads than previous version

2019-05-09 by Russell Graves

Most things handling lots of power can catch fire if something goes wrong. I didn’t see the reviews of them doing so, but I’m not particularly surprised.

2019-05-09 by Russell Graves

If there are board design differences between v117 and v118, that implies that the firmware change isn’t the only difference.

If you figure out how to upgrade it, let me know - but I just don’t see much point in putting a lot of effort into these controllers. There are enough issues as-is, and promises of “Making it all better” from the people who released the troublesome ones doesn’t mean much to me.

2019-05-17 by Unknown

It is as shame as I thought I had finaly found a cheap MPPT controller with some potential. Also the fact that MSB is very fast to anwer questions made me hope.

Today when I checked in on my system the MPPT tracking was way off. I had hoped that the problems people had with V113 was corrected, but it seems that at least on V117 they are still there.

MakeSkyBlue MPPT controller V117 not tracking - YouTube

2019-06-07 by ‘yes’

Very bad , same error till v117, it’s still there till v118. MSB is finding it difficult implement partial shading effect on the mpp tracking method they used … meanwhile still working on my 50a libresolar project will be launched within next month. Reviews here has been helping in updating the firmware accordingly …

2019-06-20 by Unknown

One thing I don’t recall seeing is the firmware revision of the unit you are reviewing. This is displayed briefly on power up. The V113 could get a little squirrelly at times and I suspect that is what you have. I have two of those and I have two of the V118. Night and day difference, including extra screens. You mention the 190v rating. READ THE MANUAL. They say you are asking for trouble if you run it there and you should keep it under 150v. They also indicate input ranges depending on battery voltage. So far, I rate the V118 as Good Stuff. The case is aluminum and some folks have tried mounting heat sinks on the back. I think that is a great idea to reduce fan run. My control room generally operates above 100F and the fans run a lot. The thermistor mentioned is not to compensate the battery charging, it is to protect the battery charger. If you have a large enough battery in your system you don’t have to worry a lot about temperature. BTW, this V118 will actually go into charge mode in moonlight with solar volts input lower than battery. No, it isn’t a MS Classic or an Outback FM, but I like it.

2019-07-01 by Russell Graves

If someone ships me a v118 firmware unit, I’ll certainly poke at it - but I’m not going to spend money on one.

The sales pages at the time I purchased the unit repeatedly stated it was a 190V unit - though, as has been covered in the comments, that’s probably unwise. I still expect it will stand up to it, though.

However, I disagree entirely about a large battery and temperature. Temperature compensated charging is one of the more important things you can do to keep a battery bank happy for the long term. Even a large bank will follow seasonal temperature swings.

2019-07-14 by Carlos

At least version 118 works beautifully! Today it was cloudy and it was synchronizing very well with every change in light.

2019-07-17 by ‘yes’

Doesn’t fail all the time , but definitely will… that’s poor tracking algorithm , carlosgs .

2019-09-27 by Unknown

Do you know how to factory reset this unit?

2020-05-05 by Zaziki

the V118 Version is totally fine, working for a year now without tracking issues.
The display is this one :

Not sure for what the 7 wires are needed - my plan was to grab the data from there.

2020-07-23 by Angle

Hi friends
I need firmware and design details of skyblue solar charger
I will purchase in good price.
Thank you

2020-08-04 by Unknown

I bought a powermr the only difference between this and makeskyblue is that it comes with a long rave about how makeskyblue is inferior other than that … identical
My unit had a bit of swarf under one fet which made the case live!.
After i removed this the unit would underread battery voltage and overcharge.
(And the case would float up by the amount of this underread)
Now with an external link from case to ground all seems good.

Really keen on any discussion of hacking the firmware
I really hate the autosense battery voltage!!

2020-09-06 by Oprem Dobro

I got MSB 60A V117
I’m using it for one week now, the problem with poor MPPT tracking isn’t resolved so far, I have to reset the PV input circuit breakers every morning to start harvesting the sun’s energy.
Also D00 Load setting doesn’t work.
It looks like half unfinished product, complete waste of money.

2020-09-11 by Kuba

Hello friends,
I have bought powmr mppt 60A charger, it came broken and they don’t want to send me another piece. I think, that the microcontroller is broken.
I would make the repair by myself, but I need the software. Does anyone have the firmware for the uC? The problem is that the lcd lights up, but shows no Data, the led on the board is not blinking and the controller doesn’t charge.
Thanks for your help.
Best regards

2020-10-16 by Oprem Dobro

What country you are?

I have Nu-Link offline firmware upgrade box with version 118.

2020-10-16 by Oprem Dobro

Any progress with your project?

2020-10-27 by Oprem Dobro

One months ago I got Nu-Link offline firmware upgrade box with version 118.
For the last 30 days, the device works like $600 Midnite Classic 200.

2020-12-26 by Peter W

V119 60A seems great. 220v capacitor inside. Not had any issues yet running VOC 152V - I think MSB have been listening and responding to customer reviews. Peter

2020-12-28 by Peter W

Also the voltage multiplier has been addressed. The WiFi allows remote changes to parameters. I have had no issues with the MPPT chasing daisies ;D

did any one get data logging working for makeskyblue v118 or will only option be to try and steal packets from the v119 wifi ? planning on using 30 chargers soon sick of replacing units worth a few thousand $ every time they die

with the v119 any efficiency gains with the higher VOC ? with the v118 I found I could only use 1.5x the battery voltage = 2x solar panels 48v bank with 2x 250watt 36VOC panels = 72v

if I used 108 volts efficiency dropped and 144 volt seemed quite bad it felt like it was a PWM

my understanding is the powmr are half the ratings ie) 60A on the LCD will really only be 40a max using a current clamp

I’ve not kept up with the developments on them. I’ve heard they’ve improved, but after my experience, I’m happy to stick with Midnite’s units and have a boring unit, if somewhat more expensive.

What on earth are you doing that requires a several thousand dollar charge controllers you’re going to replace with the MakeSkyBlue units?