EPSolar MT50 Remote Meter - 12v Solar Shed 

Kris Harbour I am thinking about getting one. are you still happy with yours? have there been any problems?

My 4210 is happy after 2 years of use. No issues. I wish there was a way to hack the MT-50 display to only show PV out put ALL of the time!

@@ddd228 buy a eLog01 module and plug the MT50 and a USB cable at the same time then set up a Raspberry Pi Zero W with a screen to show the PV data you want.

Cheers for the comment Chris on your findings. I've been following along on your channel - your system has grown nicely. For the price the EPSolar kit is great value and from what I have seen very reliable too.

Just purchase the 40 amp epever and mt50 will be here today thanks

:) each to their own!

My 60 amp epever tracer says not for use with lithium batteries right in the box

@@reaj2010 Because people dont know how to properly set the voltages is reason. If someone gets one and hooks it up with out setting the limits then they are going to over charge the lithium batteries. Because If you dont set the max charging voltage to 25.1 volts its going to make the lithium batteries angry. Its still running my batteries right now. Go to techluck.com to see how to set the proper voltages.

I bet that does help keep it cooler.

@@shartne I spray my array with a garden hose.

@@ddd228 I use to do that all the time on hot summer days. It helps.

@@shartne I may rig a mister system !!!!!!

@@ddd228 Let me know how that works out. It is always better to just get more panels I have found out from experience if you got the room get as many as you can possibly get. I need to finish another tracker I may have went to complicated. My panels stay cooler on a tracker than on a roof or laying on the ground.

Thank you very much.

For the controller to know what load is being taken from the battery the load does need to be connected to the load terminals of the charge controller. Loads taken directly from the battery won't be shown on screen or in any of the statistics.

@@AdamWelchUK what is the max amperage you can draw on the mppt charger load output?

aaron picksley It’s whatever the controller is rated for. So my 20 amp version allows for 20 amps from the load terminals.

Really useful feedback thank you. I can imagine it is rounding, but you'd expect it to round to the closest tenth rather than round up every time - that's interesting.

Hi Adam, I think what is happening in this example is when my meter reads 12.53v for example the MT50 is measuring 12.55 and showing 12.6v. Most of the time this is OK but trying to use it to check internal resistance doesn't really work. I am interested to see how your lithium battery plan works as I have 60 cells I am hoping to use to build a battery.

+Ian Coster Glad to have you along Ian. Thanks for the extra info. I'll do an update video on the lithium cells in the new year unless something worth reporting happens before then.

Hi Adam, how is the MT50 working for you? I have found a little quirk that initially had me worried about my battery. The voltage on the MT50 has been showing a drop to 11.9v when I have a fairly moderate load on approximately 1A. I have since checked this a few times against my meter and it is showing 12.2/12.3v under load. Sometimes the MT50 seems to return to a more accurate figure. I know my battery is a little under charged at present but that is mostly due to living in the UK. Let me know if you find anything similar.

I'm not using this currently - I have my eBox-Wifi-01 plugged in so I can remotely monitor my Tracer A. I do intend to change the soalr charge controller on my lithium ion pack from the ViewStar to the Landstar 1024B and plug the MT50 into that so I can better monitor that pack, but I haven't got around to that yet. The MT50 simply displays the results calculated by the charge controller it is connected to. So it sounds as if your charge controller is reading a low voltage under load. Could this be a simple as your cabling isn't as heavy as it could be - causing a voltage drop under load?

The MT50 will allow you to monitor the whole system and it will let you adjust the charging parameters if you’d like to charge your battery a bit lower. It seems like a good option to me.

I haven’t tried the Bluetooth ebox. I’d probably go with that rather than the WiFi version of you’re looking to use the android app. The way the WiFi version is setup - and the removal of the client mode, makes the Bluetooth version a little more attractive to me.

@@AdamWelchUK Thanks for that Adam, I have asked Epever if the bluetooth device is compatible with the AN series (I just wanted to be certain given the MT50 compatability problem that you kindly highlighted). Sorry to bother you further, but will I be able to make settings changes to the AN controller using the bluetooth adapter. TIA if you can help.

The battery just got killed.

Sounds to me like all your loads are connected straight to the battery - not to the load terminals of the charge controller. I’m afraid it can only display any devices which pass through it. However the load terminals aren’t the place to connect your inverter, they aren’t built for that so having it directly connected to the battery is best.

@@AdamWelchUK Thanks Adam. Of course you re right. Thanks for the help! Nothing connected to the load

Yes you can set the charging limits to be practically anything between 9-17 volts I think it is (or 18 - 34). In my other experiment I wanted to use an off the shelf controller and didn't want to change any of the parameters to see if they can work.

Thank you for the feedback , My tracer 1210A just arrived ,.. trying to use it to charge 3S 20P 18650 pack . Can you recommend the settings to be used for 3S Li-ion configuration ?

Each of the charging stages (and low and high voltage cutouts) can be programmed between 9-17 volts with the MT50.

I believe if you went for an MPPT solar charge controller you would be better having them in series.

NO!!!!!!!!! Use the MT-50.

+Henrik Bo Carlsen My recommendation would be to test both and go with what your experience suggests. Generally the manual suggests higher voltages - so in series but that may just not work best for you. I found in winter panels in parallel would produce more watts but in summer it seems to make sense having them in series. My cable length is very short though and I use a reasonable gauge. May not be the concise answer you were after but hopefully the testing will be fun for you!

Adam Welch Ha ha Adam......highly appreciated, and just the answer I wanted, as I thought it was not as simple as the manual suggests.....and your answer reflects application experience. You are certainly also correct, that experiments are fun......if the UK climate is not optimal for solar harvest, it may be even worse at the lattitude where I have my solar panels in our summerhouse in Sweden. Thanks again for your good videos and wise comments. Best regards Henrik

Adam Welch n

Interesting perspective. Hadn’t thought of that. Thanks.

Sorry no I don’t believe so. Only some EPSolar and EPEver solar charge controllers.

Thanks for the reply :)

1. This is an interesting question with quite a long answer - but I'll try to keep it short. If you buy a 10 amp version (1210A) the solar input will be limited to 10 amps. The strange thing is you seem to be able to attach more according to the manual. The manual says you can attach 130 watts at 12 volts. That's just over 10 amps. However it goes on to say the max PV power is 390W at 12 volts. So I believe you can attach panels which are capable of supplying more than 10 amps, but must be less than 30. However if you array provides more than 10 amps, this will be limited. So in theory you can attach an array that will produce 10 amps in the winter months, and something that will produce much more in the summer, but you wont see that power. Check out page 10 of the manual for the stats to which I am referring... admw.uk/iL 2. I'm afraid I can't answer this. Too many variables. It depends on you use, where you are in the world, which direction your panel is pointing etc. etc. 3. You can use a higher voltage panel on both PWM and MPPT, however it's much more efficient to use a '12 volt' panel on a 12 volt PWM controller, and a '24 volt' panel on a 24 volt PWM controller. If you are using MPPT then 99.9% of charge controllers require the panel voltage to be higher than the battery voltage (I know of one controller that works in the opposite way). Each controllers manufacturer will usually produce stats on what is the most efficient setup on their controller (eg. page 9 on the tracer a manual I linked to). 4. I'm a fan of buying the next size up. My 20 amp controller will probably never see more than 10 amps. I think it ensures components aren't stretched to their limits. Lower heat, lower strain, longer life. It's worth noting though that the maximum claimed efficiency may well be in the 80-95% load region. I hope that helps.

@@AdamWelchUK Good answer,Adam. Go for the 30 Amp MPPT CC. You can grow from there.

Hi. No, that is the low voltage reconnect parameter. Its the voltage at which the load output is turned on again after a low voltage disconnect has happened. Low Volt. Disc is the parameter you would want to set to 11 volts if that is what has been suggested. Cheers

fantastic, cheers Adam!

+87xfute Yeah it's the suggested setup - two panels in series (nominal 24v actual ~40v) and the battery connected at 12 volts. It's exactly how I have mine setup.

Adam ... think you just confirmed my intended change to my system. EPEVER 40amp model to 12v battery bank, 12v load (LED lighting). Solar panel currently 12v 200W. great in summer but charging falls behind in colder months. So was indeed considering panel replacement with a 24v 300W panel. Manual(to me) wasn't clear about 24v panel to 12v battery&load . was concerned over EPEVER efficiency decrease going from 12/12/12 to 24/12/12 Volt system. next day I have I'll check your past videos if you covered this.

The MT50 meter is mentioned in the Tracer A manual (as well as a few others) so it is definitely supported. Unfortunately I am aware of some MT50s not being compatible with some charge controller models (video soon I think), but I’ve not been made aware of a MT50 that has worked, and then stopped. Perhaps support misunderstood your issue? Or am I being too kind?

Could be, however I believe there are now two versions of the MT50 and I have heard some don’t work with a small number of controllers. Perhaps it’s worth asking EPEver customer services?

+pirucreek Ah well the shed has its own time zone don't you know :-)

ah, you finally fixed that Chameleon circuit then

Yes 99.9% of the time it’s just a display. It can however program your solar charge controller as well, but once that is done, or you’re happy with a default setting then it’s just a display. As long as your charge controller is still working you don’t need to replace the MT50 if you don’t want to.

@@AdamWelchUK tnk you. I appreciate your advice😀

Both the MT50 and the Wifi module allow you to fully configure the tracer. You can also use a USB cable (check my other videos for a really cheap home made one). It’s easiest probably via a cable or the Wifi module using the windows software, but there is an Android app as well available on the EPSolar website.

thanks for the info and for replying!!!

@@AdamWelchUK Can you direct me to the video with the home made USB cable? I don't see anything titled as such. Thank you

@@SteveGuzer sure... EPSolar Solar Station Monitor software & a cheap USB cable - 12v Solar Shed ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-r3LrWeYYtnQ.html

@@AdamWelchUK the one I just bought 8/21 shows the cable with the purchase along with the MT50

I've had a look at the information on the EPSolar website but I've not bought one (actually I haven't seen anyone selling it yet). There's nothing too interesting in it for me. On the surface it looks like a Tracer A series charge controller without the LCD except for two important changes. Firstly it is common negative (where as EPSolar have generally made common positive controllers) and secondly it has the ability to switch external equipment. I'm sure for many that will be of use, but not for me in the shed. Are you thinking of getting one?

You can set either (or it will choose for itself). I use one of these on a 12v system and a 24v system.

Thanks Mike. I’m guessing you know I’ll suggest a Tracer A or AN. If you’re looking at a 12v system then you’ll need the 30 amp controller but 40 amp would possibly be better if you want to take full advantage of your panels. If you run a 24v battery bank you could reduce that to the 20 amp.

@@AdamWelchUK Thanks Adam. I'll probably tighten my belt somewhere else, and go for the 30 or 40 am Tracer.

My every day MPPT solar charge controller is the EPEver Tracer A. But I also have used and like the EPEver TriRon range, the Eco-Worthy 20 amp SCC and the UEIUA CPT-LA10 works quite well for its very low price. All of them will cope with a 22 volt panel and I've done videos on them all that you can check out. However, I wouldn't expect big things from upgrading to an MPPT solar charge controller. You might see an additional 10-15%, but that's only 3-5 watts on a 30 watt panel. Unless you've run out of space for panels, you might be better buying another panel rather than a new charge controller.

thanks a lot for your reply just subscribed !!so am planning to buy a 250w solar panel maybe in 3 months not now but the problem is my actual charge controller can handle only 10a so definitely it will damage it am thinking buying a good MPPT charge controller 1st and next a 250w solar panel,is it good or not? but i don't know if the MPPT charge controller will work properly with my 30w solar panel is it going to charge is same like my pwm if yes i will be happy because next i will upgrade to more solar panel and more battery buy little little or it won't charge it am worry about that.i don't want to waste my money because it's very expensive> sorry for my bad english

+zacarias d'melo Hello. No I believe the dual battery unit (which is quite an old unit) uses a different meter - the MT1. The MT50 is compatible with the RS485 controller versions.

A good question, and the MODBUS standard allows for this. You'd need to set each charge controller to have a different ID (I think you can have up to a couple of hundred on a bus technically) and then you could communicate with them in turn or flip between them. Unfortunately I don't think EPSolar have implemented this into the design of the MT50 or really in the design of the RS485 port on the controller. I'm not sure if the MT50 will even connect to a charge controller that hasn't got a slave ID of 1 - which is the default. Something to test. I've done another video in the past where I made a USB cable and tested the PC software. It is designed to save connections to multiple charge controllers, but I don't think it allows communication with more than one at once - actually I could probably test this at some point as well. So assuming that they haven't implemented this in the software (and you can kind of understand why with a budget product when most people will only ever have a single unit) then you could look at doing a hardware approach. The cable may have eight wires, but in reality there are only four connections so a four pole switch could be used to switch the MT50 from controller A to controller B (and C, D etc.). The meter would reboot (takes about 2 seconds) then you'd be connected to a different controller. There is scope to suggest you might only need to switch two wires, A and B of the modbus communication and you'd only have to wait for the MT50 to send another update request for the meter to read a different controller. Grounds could possibly be commoned and you might only need the 5v rail from one controller. As you can tell I'm thinking out loud. So don't go trying this without some additional thought. Sorry - I've answered your question by raising a lot more haven't I?

Thanks Adam for such a detailed explanation. Yes if they haven't considered it as requirements it's going to be a problem if the master cannot address each slave via a different address then your switching option is the only option. I'll only have two so I think I may as well just have two MT50 units. Thanks again for the response.

+Dave Winwood No problem. It would be nice if it could be done. I may investigate a bit further but I think the solution will always be a bit Heath Robinson.

Did you get round to testing this? Just setting up another 3 controllers on the motorhome, really don't want 4 x mt-50 cluttering up the place! A 4 way 4pole switch would be do-able... Cheers

I'm afraid not James. The protocol may be the same but the ID numbers for the information may be very different. The screen will call the battery voltage for example but the response may be something completely different - or simply an unknown response or no response at all.

+TheLastPost I started with a cheap PWM solar charge controller and I guess I got the bug. I've upgraded numerous times because I like the technology behind the charge controllers. I believe Julian did use some commercial solutions but found them lacking in one way or another and decided to design his own. He then sold almost 1000 of them. For me the extra features of most commercial charge controllers are very handy. Load control and displays showing how they are performing are extras that I like to have. I have created a few of the arduino versions of Julian's Charge controller and they are excellent (although arduinos use much more current than the pic in the original PWM5). Julian also kindly sent me an original PWM5 which I use on a small car booster system. It really is an excellent charge controller. MPPT is obviously an advantage for grid tied inverters and systems that are using the power during sunlight hours or have a limitless storage facility. For me PWM is probably the sensible solution as I use my power in the evenings generally when it's not being generated - although I've now run out of roof space and MPPT is the only way to get those extra milliamperes!

Doh, youtube cut you off after 'for me PWM is probably..?' Yes Julian's PWM does look to be a great device and I wish I was around when he was producing them! Think it's out of my league to make one, so was looking at getting one of those very cheap tiny (£4) PWM's from china to charge a small array (I have 16) of 12v 2ah SLA batteries. It's just a shame the voltages on the Chinese PWM have quite high and low limits. I'm very impressed by your system, looks great and can see the advantages of you using MPPT, I'm a numbers geek myself lol. I just wondered why Julian would be using PWM as he has quite a few panels himself!?

+TheLastPost For me PWM is probably sufficient but I have now run out of space on the roof so MPPT is the only way to get a few more milliamperes! The arduPWM5 is quite a nice little project - but can be a little costly if you're only making one and don't intend to use the bits on other projects. Julian did comment on one of my videos and said he would order an MPPT charge controller. But it's the wrong time of year to be playing with solar really. The cheapest charge controllers are usually setup for flooded cells and can be a bit high on AGM. Spend a little more money and you'll find one which has different settings for different cell types.

thanks Adam, some food for thought there. Thinking along the cheap Chinese solar controller and it's high 14.8 boost and 14.4 charge voltage, would a boost buck converter after the controller limit it to a voltage that's more kind to sealed lead acid batteries?

+TheLastPost I'm afraid not. The charge controller wouldn't work as it needs to be powered by the battery and it's unlikely a dc to dc converter would allow the reverse current.

Colin Hickey has used an ESP8266 to interface between the EPSolar station monitor and the charge controller ( ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rEdn8w4WdXA.html ). There's also a few people using raspberry Pi's to display the data from their tracer. I plan to do the latter at some point, but there's so little time!

You may becoming a cropper to the voltage rules put in place... 2) The following rules must be observed when modifying the parameters value in user battery type (factory default value is the same as sealed type): a. Over Voltage Disconnect Voltage > Charging Limit Voltage ≥ Equalize Charging Voltage ≥ Boost Charging Voltage ≥ Float Charging Voltage > Boost Reconnect Charging Voltage. b. Over Voltage Disconnect Voltage > Over Voltage Reconnect Voltage c. Low Voltage Reconnect Voltage > Low Voltage Disconnect Voltage ≥ Discharging Limit Voltage. d. Under Voltage Warning Reconnect Voltage > Under Voltage Warning Voltage ≥ Discharging Limit Voltage. e. Boost Reconnect Charging voltage > Low Voltage Disconnect Voltage. I've just swiped that from page 18 of the tracer manual. If that doesn't help let me know.

Ah, that worked! I was so busy with the MT50 manual that I ignored the main manual lol. Had to work my way from the bottom up to comply with the voltage rules. Anyway, many thanks! I owe you a ginger beer!

Glad it worked for you.

Well firstly I’d ask if you have an android device to connect to the ebox, otherwise it’ll need to be a windows device to use the official EPEver applications. As long as you have a place to mount the mt50, I’d probably go with that. The menu system is reasonably easy to navigate and you can change every parameter with it - except for the pre set lithium settings (but these settings can be set in ‘user’ if required). It’ll display the most important stats all the time without needing to power up and connect another device. Camping is often about switching these things off isn’t it?

@@AdamWelchUK Yes camping is about switching these things off - agree absolutely hence I went ahead and bought one with MP50 even before I read this reply. I just didn't know, if every parameter canbe changed. Now I am feeling better. Also I am glad we think alike :).

@@AdamWelchUK Hi Adam, I have one more question and I think you have an answer for me as you have tinkered with epever mppt chargers. Mine 3210 I think is the number is the newer version with 2usb and 1com port for my MP-50. Well the question is related to charging 2 different sets of batteries. One being a dual batt setup for my inverter and one just a smaller leisure battery for 12v lights in the caravan. Now I am planning to install a 3 way swith allowing me to send pover from controller to 1st, 2nd circuit or both at the same time. Do you think it's a good idea? How would the controller cope? Would I need to change the battery setting with every switch? I really don't like an idea of charging that small leisure battery via power from controller via van's charger due to substantial losses (caused by 12v going to 240 then back to 12v), but is there an elegant way of charging it without separate panel and separate controller? Many thanks.

Peter If you intend to flip between batteries I’d suggest you need to isolate the solar first (otherwise this will power the charge controller whilst it transitions) then flip the switch between batteries before switching the solar back on. That way the charge controller does a proper reboot between batteries. The difference in capacity won’t bother the charge controller - that setting in the menu is more for reference if you use the voltage compensation charging setting. I probably wouldn’t recommend attaching the two different sized packs in parallel. If one has a significant voltage difference to the other an awful lot of current can flow between the two. Having two different sized is not great when charging or discharging anyway. Perhaps you can use some kind of dc to dc converter to charge the smaller pack from the larger pack which is connected to the solar for the best of both worlds?

I agree with you, if one has a significant voltage difference to the other an awful lot of current can flow between the two, but I can always monitor the voltage difference and only allow connecting the both packs (via 3 way switch - 1, 2 and 1&2) when they aren't too far from each other. I'll have 50mm2 cable ready to link the battery packs (last maybe 35cm is a smaller cable perhaps 10mm2 which is build in the caravan battery enclosure (not sure if I can leave that one there, would putting a 150A breaker on 140a relay protect the cable, in case there is an extremely high current?). My second idea was to put a split charge relay BETWEEN the two different sized packs (in parallel), which would only charge the small battery when there is surplus power allowing some automation with a relay just like they do it in a camper vans. Which idea sounds better to you? Also what fuse shell I go for considering the relay is 140A, but cable is 50mm2 (btw do you think it's a over kill? I also have 5m of 35mm2 starter lead cable lying around). Btw the solar is isolated of course and will be switched off between transitions, however if I go the route of relay than that step will be redundant imho. Thanks a lot for helping me with my project!

nope.

It totally depends on what you are connecting as a load. I don't use an external shunt, but I use fairly light loads on the load output of my tracer A. It's got it's own shunt showing you what you're pulling and a low voltage cut off already built in. Now I do pull a few loads directly from my battery bank, but not anything very big for very long, and anything I do pull I don't leave unattended. If however you want to place a few loads directly from your battery and you might leave them running when you're not about a separate low voltage disconnect is a good idea (unless your item already has one built in like a lot of inverters), and shunt and display gives you a good idea on what is happening live.

I’m afraid not. The load voltage is the same as the battery. You’ll need a dc2dc converter to drop your 24v battery voltage to 12v.

Thank you for your reply. How would this system sound to you? x3 100watt 18v solar panels wired in series to create 300w 54v. This will then be charging x2 100ah batteries wired in series creating 24v. I would then be running a small 300w inverter to run my 25w pump.(around 2amp draw with inverter at 24v). I would then use the load terminal to operate a relay switch to turn inverter on. Will i get the most from my system with this controller? Thank you

Sounds reasonable - your inverter will run directly from the battery and you load will switch a relay to enable it - is that right? Out of interest are you going to automate the load output somehow?

yes i have found a durite 24v relay switch so when powered the inverter would be on. I was under the impression you are able to program the tracer so the load will come on e.g. 2hours before dusk, stay on 1hour after or time when the load goes on and off? Is this the case? Many thanks

I sourced this from section 5.7 of the mt50 manual online.

Generally yes - mppt solar charge controllers will convert the higher voltage down to the charging limit set on the controller. In a pwm solar charge controller the panel is connected straight to the battery for short pulses. The panel voltage drops to the battery level while it is connected. It’s less efficient but perfectly safe. The bigger question is if your solar charge controller is both set correctly for your battery and working correctly!

@@AdamWelchUK Dear Adam, many thanks fro your reply. I have LiFEPO4 batteries 4 packs total 12.8 VDC 120Ah and I have 4 solar panels total 200 watts, if I connect these panels in parallel it can provide approximately 15 VDC but if I connect them in sequence it can provide either 30, 45 or 60 VDC, could you please advise which voltage charge is best for my LiFePO4 batteries and if I charge it with 60 VDC can it damage my batteries? I have this solar charge controller www.amazon.com/gp/product/B07FNKDX5M/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 and this solar panels www.amazon.com/gp/product/B00YI0DSO8/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

In the normal screen the ok button controls the load output if you have it set to manual. it allows quick access I guess. Normally you want to be pressing the other buttons to wake up the screen.

Thanks

It’s totally optional but it does allow you to adjust a lot more settings as well as see more information at the same time.

@@AdamWelchUK Thanks for answering. Thing is about more choice, I don't understand any of it, lol. I wouldn't know what to adjust or why I was adjusting it 😕

If you’ve no interest to change anything then to be honest the MT50 is probably a waste of money. If you want to understand more about the settings watch more of my videos :-)

Shame. Three years is probably OK. ;-)

@@AdamWelchUK Easy to fix,Adam. Pop it apart and clean BOTH contacts with iso & a Q tip. Done.

Actually,there is an assembly issue with the MT 50. Two of the contacts were covered,not allowing full contact. The ribbon strip covers part of the contacts! I used Shoe Goo to keep it out of that area. See the photo,Adam. [img]i.imgur.com/6UPadP9.jpg[/img] I used a tiny dab of ant-seize on the contact points.(Conductive) (Never use C.A. near an electronic component.) PS: Thank you for your review. I just added to it. i.imgur.com/6UPadP9.jpg

Nope. I’m afraid not.

I have one. It’s nice to see the temperature difference between the charger and the battery - but it also allows you to take advantage of the temperature charging adjustment - when the batteries are warm or cold it’ll increase or reduce the charging voltage to keep them in tip top condition.