MPT-7210A Questions


MASSIVE restock of EV Batteries at www.batteryhookup.com 5% coupon "POWERWALLS"

xhamma

New member
Joined
Nov 18, 2018
Messages
1
Has anyone probed the serial port on the MPT-7210A? I did a quick google search and was surprised that I didn't find anything.
 

camolas

New member
Joined
Jul 23, 2019
Messages
1
Hi all, my lcd is all white (only backlight is showing) afther a small electric discharge from my body i feel a small discharg on my finger when i was to push one of the7210A buttons... thenwhite screen :(i went to ebay and bought this1.8 Inch 128 x 160 Serial Spi Tft Color Lcd Module 128X160 Display St7735 W W8V3. But is still getting thewhite screen:(the7210A is working i can read 25v from a 12.5 input.
If any one can hellp me please..
Thanks
 

saslava3d

New member
Joined
Jul 23, 2019
Messages
1
thanar said:
>I also believe these units are quite good for their price, give lots of control over the charging parameters and can
>be used as DC-DC boost converters reliably. However, a 100Wp panel is the minimum (says so in the chenglish
>manual), the tracker just doesn't work right under a smaller panel.

I didn't find that clause in the manual when I researched it, and mistakenly assumed that the unit itself would not consume even 10W... my 20W panel in full sun *does* boot it up correctly but once I try to draw any power to charging a battery, it goes flaky as reported here by others.

I was hoping I could get a small trickle out of this unit into my 36V bicycle pack... but it looks like the fan/display/losses consumes too much to function correctly...

I can put it to use other ways, so it isn't a total loss... but I'm looking for a good and inexpensive way to slow-charge/maintain my bicycle pack with solar...
 

jon218white

Member
Joined
Jul 18, 2019
Messages
135
Hi
Im concidering getting one of these not sure now, is this an isolated incident?
 

jdeadman

Member
Joined
Mar 28, 2017
Messages
967
mines been running for 2 years with little problems. The biggest thing you have to know about these is that they are Boost Only charge controllers Your solar in has to be lower than the min of your battery. I have 12V Panels and charging a 7s (24V ) system.
 

jon218white

Member
Joined
Jul 18, 2019
Messages
135
Yes buck boost soppose they are less efficient.
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,662
And they Arent mppt. They are manual ppt and not automatic. They work but yeah you get what you pay for
 

rev0

Member
Joined
Oct 3, 2017
Messages
372
We just need someone to do a brain transplant on it to make better use of the hardware. I've already worked out most of the power path components/functionality.
 

Alexander9000

New member
Joined
Oct 1, 2021
Messages
3
Here's some scribbles about the circuit diagram ifanyone is interested, I only bothered with the main power path so I can add a loggerand some bits trying to figure out what was wrong with the fan:


View attachment 2046


The shunt before the battery outputis approximately 10mOhms, whichgave me 9.64mV/A at 2A load.
Hello. I saw your post with a schematic drawing from a solar mpt 7210a device. You drew an approximate diagram according to which it operates this device. Could you help me and tell me what the name of this glass part is? I have it broken. I want to replace it, I don’t know what it is? I will be very grateful if you help me
 

Attachments

  • IMG_20211001_125441.jpg
    IMG_20211001_125441.jpg
    3.2 MB · Views: 80
  • IMG_20211001_130417.jpg
    IMG_20211001_130417.jpg
    4.5 MB · Views: 83

Oberfail

Member
Joined
Jun 22, 2021
Messages
253
D is commonly used for Diode, just google for glass diode, i dont know the parts number tho or the exact values it needs.
 

rev0

Member
Joined
Oct 3, 2017
Messages
372
Hello. I saw your post with a schematic drawing from a solar mpt 7210a device. You drew an approximate diagram according to which it operates this device. Could you help me and tell me what the name of this glass part is? I have it broken. I want to replace it, I don’t know what it is? I will be very grateful if you help me
It is just a simple diode, any will likely work, here's the likely part: https://www.mouser.com/ProductDetail/Microchip-Technology/1N4148UR-1?qs=%2BRKXB2WKlSdXiNZTe6I9fg==

You should be able to replace with any silicon diode with similar voltage/current rating.
 

Alexander9000

New member
Joined
Oct 1, 2021
Messages
3

rev0

Member
Joined
Oct 3, 2017
Messages
372
Thanks. yes I figured it out a little. it remains to understand what kind of diode it is? how many amperes? and how many volts? I think this is a 100 volt diode? ampere?
I'm just assuming it's around 200-500mA based on the package, the glass packages aren't used for high power diodes. I'm sure using a 1N4002 (1A 100V) or higher voltage versions (1N4003-1N4007) diode that is easy to buy/scavenge would work also.
 

Attachments

  • Screenshot_20211002-034212.png
    Screenshot_20211002-034212.png
    886.7 KB · Views: 73

mschaus

New member
Joined
May 17, 2022
Messages
1
So like many people that purchase these I'm not really using them all as intended. I use it in conjunction with a 12v led power supply to charge 24v and 36v lithium packs for e bikes and off grid UPS kits. At this point I have 3 of these things and I have the same issue with all 3. I will set the amps to 9 or 10 then start charging my packs, but the charging amperage never goes above 3.5. I've tried different voltage settings, running many battery packs in parallel,as well as setting the battery amp hour and charge time to very low. I understand lowering the amperage as the batteries get fuller is good for the batteries, but why won't it give me more juice?
I purchased a 250W 12v led power supply to power this thing so I could get a fairly rapid charge (at least up to 80%) on my 16ah ebike battery bank, but now it takes 3 times longer than I had planned on.
The batteries for the ebike I'm charging are 25.9VDC 7 cell 20650 units with their own BMS and low voltage disconnect.
I've got the high charging voltage set to 28.8 in the MPT-7210A.
I've attached a photo of the setup and readout on the display.

View attachment 15858


Any advice would be greatly appreciated.
Yup, you and me both got duped by the advertised specs of this device. I did some experiments to find that the output current is limited by the voltage difference between input and output. When the input voltage is higher, and thus closer to the output, you can get more current. In your case of going from 12V to 26V, a delta of 14V I would expect maybe ~3.75A, about what you are getting.
I laid out all my findings in a blog article: https://mschausprojects.blogspot.co...r-from-mpt-7210a-boost-charge-controller.html
Cheers
 
Top