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...
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 meHere'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.
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==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
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?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.
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.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?
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.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.