Squonk Posted February 19, 2019 Share Posted February 19, 2019 Good day to all. I am just getting into solar PV this so please excuse my ignorance. I have a couple of questions for the experts! Can I get some suggestions about what AC battery charger will be suitable to charge a 2.4kWh Pylontech battery setup? Can you have have 2 chargers connected to the battery set at the same time? i.e. Inverter/ MPPT SCC and an AC charger? I am planning on putting in an off grid system but would like to be able to charge the batteries if PV power is not available without connecting the PV inverter to the grid ie. hybrid inverter setup . I do not want to go grid tied due to the ridiculous municipal costs. Does anybody have a list of inverter/ MPPT models or brands that are compatible with Pylontech (or other Li batterries). I cannot find a website for the Pylontech that actually specifies the requirements for suitable inverters and MPPT's. How do you determine the voltage and current charging requirements for a battery? Do you have to match the charger output specifications exactly to the battery set or can you use a larger or smaller charger? Any answers will be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted February 19, 2019 Share Posted February 19, 2019 7 hours ago, Squonk said: Can you have have 2 chargers connected to the battery set at the same time? i.e. Inverter/ MPPT SCC and an AC charger? No, I guess its possible but not advisable at all. The Charging side of things should be able to communicate with the BMS of the battery to ensure that the battery isn't over charged ext. 7 hours ago, Squonk said: I am planning on putting in an off grid system but would like to be able to charge the batteries if PV power is not available without connecting the PV inverter to the grid ie. hybrid inverter setup . If i understand you correctly, you want to run offgrid and only connect to grid to be able to charge from AC. Your inverter should take care of this, so choose the correct inverter and forget about the separate AC charger. 7 hours ago, Squonk said: How do you determine the voltage and current charging requirements for a battery? You will find this in the Data Sheet for the battery. I remember 25 amps max for charging and discharging, and 53.2 Volts max charging Volts. 7 hours ago, Squonk said: Do you have to match the charger output specifications exactly to the battery set or can you use a larger or smaller charger? I guess you can charge with less amps, but see not benefit or reason to do so. Dont play to much with the voltage. Stay within 52 to 53.2 volts. 7 hours ago, Squonk said: Does anybody have a list of inverter/ MPPT models or brands that are compatible with Pylontech (or other Li batterries). I dont have a list but know of the following. Victron, preferably used with ESS and the correct cable does a great job of controlling the Pylons. Axperts (not my first choice) used with ICC and their cable is also approved. There might be others, but i dont know them. Please only use approved inverters otherwise you will void your warranty. Quote Link to comment Share on other sites More sharing options...
Sidewinder Posted February 19, 2019 Share Posted February 19, 2019 @Squonk, I recon one of your optimum setups is as follows: Battery - Any good inverter to suit Pylontech - pv and a genny on the AC input. Which one....anyone that can adjust to the correct parameters for VoLTE and current spec for charging floating etc.. Has been discussed here. Stay away from co-charging. Just creating trouble with voltage drops and reverse current protection schemes. The modern inverters are all designed to handle all that transparently. This way you can stay off the muni/Eskimo grid, and have AC when the sun fails(to shine) and batts are near say 10% Soc. I fail to see the requirement of an additional AC charger, if you do not have the grid in the first place, and powering it from the genny is cumbersome. Let the inverter do it's thing and forget about it. would be a nice project to automate all this, specially the start & stop of a smallish say 4kva genny. Some inverters may even have a trigger built in for this, but the trick with these Makro and other specials is one still needs to pull choke and release it a few seconds later. Gennies that can handle cold start is x10 immediately, putting them outside most people's budget. So I would suggest Dr Google is you friend for an unbiased answer re recommendations. Make sure your requirements as fixed, ( written down) then you will find it. Quote Link to comment Share on other sites More sharing options...
Squonk Posted February 20, 2019 Author Share Posted February 20, 2019 19 hours ago, Jaco de Jongh said: No, I guess its possible but not advisable at all. The Charging side of things should be able to communicate with the BMS of the battery to ensure that the battery isn't over charged ext. If i understand you correctly, you want to run offgrid and only connect to grid to be able to charge from AC. Your inverter should take care of this, so choose the correct inverter and forget about the separate AC charger. Thanks for the advice. Problem is , as soon as I connect an inverter to the grid ( any inverter) the municipality requires me to go to a two part tariff which has a fixed monthly cost of R310. I will then pay 40c less per unit but the it will still be way more expensive, unless I can feed back a lot of units into the grid. Problem is with the maximum allowed inverter size of 3.6 kVA I will probably struggle to generate enough units for self consumption. Apart from that I have to add a compulsory bidirectional prepaid meter cost (R16k) ,professional engineering fees and the hassle of the the onerous registration process. Not worth it in my opinion. That is why I want to stay off grid. I have installed two DB section splitting the house into a PV supplied section and a grid supplied section for the heavy consumption items. I just want to be able to charge the batteries if there is no PV available and I reach min SOC on the battery pack. I cannot charge it with the inverter, unless I connect a generator to it, as Sidewinder suggested, but prefer to use an AC charger. I suppose I can stealthily connect the inverter to the grid with a plug as some forum members have suggested but I would like to keep it completely separate for legal reasons. So the question remains: What ac charger can I use the charge the Pylontech batteries . From what you mentioned in your reply a 25A charger which can be adjusted to 52- 54V should be able to do it. I have read somewhere on the forum that the BMS will protect the batteries and shut down if needed if it detects overcharging no matter what other devices (ICC/ESS or inverter) tell it to do. I managed to get hold of a Pylontech inverter compatibility list so I will stick to that when I purchase . It only has inverters on the list however, no MPPT chargers Quote Link to comment Share on other sites More sharing options...
Squonk Posted February 20, 2019 Author Share Posted February 20, 2019 @ Sidewinder Yes, I suppose I can automate the whole process but it will probably cost too much to justify. Your suggestion of a generator made me think. Can I not connect AC from the grid to the generator input via a contactor that kicks in when PV power reaches a certain level. I just wonder if the generator input on inverters (for instance an Axpert) is connected straight to the mains input or is there a change over switch between the 2 inputs. I also assume a inverter with grid feedback capability will never feed back on the generator input. Maybe one of the gurus on the forum have an opinion on this? Quote Link to comment Share on other sites More sharing options...
GVC Posted February 20, 2019 Share Posted February 20, 2019 (edited) Not sure if I am missing something here, but why not connect the inverters AC input supply to a normal 3 point or heavy duty plug which will charge your batteries and connect the output to your off-grid db? Basically like one would do for a UPS. Edited February 20, 2019 by GVC Quote Link to comment Share on other sites More sharing options...
Coulomb Posted February 20, 2019 Share Posted February 20, 2019 7 hours ago, Squonk said: I just wonder if the generator input on inverters (for instance an Axpert) is connected straight to the mains input or is there a change over switch between the 2 inputs. All Axpert models that I'm aware of have only one AC input, so the question (as it relates to Axperts) is moot. The AC input would connect to either the utility or a generator, never both. Quote Link to comment Share on other sites More sharing options...
Squonk Posted February 21, 2019 Author Share Posted February 21, 2019 11 hours ago, GVC said: Not sure if I am missing something here, but why not connect the inverters AC input supply to a normal 3 point or heavy duty plug which will charge your batteries and connect the output to your off-grid db? Basically like one would do for a UPS. As I mentioned I would have to do that "illegally" if I do not register with the council. I would have to disconnect the PV arrays then maybe they will accept it as a UPS Quote Link to comment Share on other sites More sharing options...
seant Posted February 21, 2019 Share Posted February 21, 2019 I saw a meanwell 500w 48v battery charger which is only about 10A but I'm not certain on the voltage adjustment range. I was toying with the idea of coupling two 24v truck alternators modified with permanent magnets instead of the stator coil. And then running it as a battery charger through a charge controller. you could use the generator auto start on the inverted. hey and then you would be really off grid. Quote Link to comment Share on other sites More sharing options...
Squonk Posted February 21, 2019 Author Share Posted February 21, 2019 6 hours ago, Coulomb said: All Axpert models that I'm aware of have only one AC input, so the question (as it relates to Axperts) is moot. The AC input would connect to either the utility or a generator, never both. Thanks for the info. Can you think of an inverter that separates the inputs? If I look at the block diagram of the Quatro it shows multiple ac inputs. Would that also be connected together inside the box? Quote Link to comment Share on other sites More sharing options...
Squonk Posted February 21, 2019 Author Share Posted February 21, 2019 1 minute ago, seant said: I saw a meanwell 500w 48v battery charger which is only about 10A but I'm not certain on the voltage adjustment range. I was toying with the idea of coupling two 24v truck alternators modified with permanent magnets instead of the stator coil. And then running it as a battery charger through a charge controller. you could use the generator auto start on the inverted. hey and then you would be really off grid. What charge controller would you use with the battery charger? Quote Link to comment Share on other sites More sharing options...
seant Posted February 21, 2019 Share Posted February 21, 2019 If you can adjust the motor that is running the alternators to a point where the voltage is fairly constant then I can't see why you can't use any solar charge controller that can handle the current. But if you are using Axpert inverters it might be about the same price to get the 5000W MPPT charger version and use that. I think you should be able to connect them in parallel like that giving you a 10kva 220v output. Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted February 21, 2019 Share Posted February 21, 2019 2 hours ago, Squonk said: As I mentioned I would have to do that "illegally" if I do not register with the council. I would have to disconnect the PV arrays then maybe they will accept it as a UPS I doubt it will be illegal if the inverter input is on a plug. Just make sure that you either get an inverter with less than 16A input (i.e. a 3Kw inverter), or have a higher output plug somewhere, let's a 25A socket wired directly do the DB. If you have a sub DB in the garage it could be a bit easier to install. The Victron MultiPlus 48/3000/35 is compatible with the Pylontech and has a maximum input of 16A. I know some guys use these on boats and the only source of power, other than solar, is shore power at the pier. Quote Link to comment Share on other sites More sharing options...
___ Posted February 21, 2019 Share Posted February 21, 2019 2 hours ago, SilverNodashi said: The Victron MultiPlus 48/3000/35 is compatible with the Pylontech and has a maximum input of 16A There are two models, one is 16A, the other is 50A. It is the size of the transfer switch and not directly related to its own charging capacilities, which for this inverter is 35A (or around 9A at full power). I was thinking that using a Skylla would make more sense, but I see the Skyllas cost enough that you might as well go with a Multi Quote Link to comment Share on other sites More sharing options...
Harbass Posted April 10, 2019 Share Posted April 10, 2019 Hi Squonk, I have almost exactly the same problem as you had in February. Same PylonTech battery; Off Grid etc. Did you manage to solve your problem? Did you find a charger for your LiFePO4 battery to run off your generator? Quote Link to comment Share on other sites More sharing options...
Jaws Posted April 11, 2019 Share Posted April 11, 2019 On 2019/02/21 at 10:52 AM, SilverNodashi said: The Victron MultiPlus 48/3000/35 is compatible with the Pylontech Can the Multiplus communicate with the Polyntech BMS ? Or do you mean its compatible in terms of setting the charging and discharge voltages in order to work with a Polyntech Quote Link to comment Share on other sites More sharing options...
___ Posted April 11, 2019 Share Posted April 11, 2019 3 hours ago, Jaws said: Can the Multiplus communicate with the Polyntech BMS ? Indirectly. You use a Venus device (aka Venus-GX or CCGX), that talks to all your stuff, monitors, logs, and relays the battery's instructions to the Multi. Venus supports a number of well-known batteries, LG, BYD, Sony/Muratta, Pylontech, REC, FreedomWon, BlueNova... and with minor differences they almost all use the same can-bus protocol too. Quote Link to comment Share on other sites More sharing options...
Hynek Posted May 30, 2022 Share Posted May 30, 2022 @Squonkdid you solve the external charger question and found the right one and a way to connect it? I am thinking about similar setup,but struggle with the same issue. Thank you. Quote Link to comment Share on other sites More sharing options...
Marius2001 Posted June 25, 2022 Share Posted June 25, 2022 I have a generator switch-over (AC vs Generator) but my problem is that the Axpert inverters switches back and to his Input. Seems that the diesel generator is not accepted as reliable input - the problem (I think) is that I have some appliances (pumps etc) that pulls a lot for milliseconds influencing the Hz and then the switching to and from happens. Was also thinking about additional a direct AC charger (from Generator to Inverter) to Pylontech batteries? Else I need to check the generator details -- I have a direct switchover as well which works perfectly but then inverter setup is skipped. Quote Link to comment Share on other sites More sharing options...
Tinbum Posted June 25, 2022 Share Posted June 25, 2022 I have an AC charger (Eltek) connected to my pack using a Teesny to read the BMS messages from the battery pack and then translate them into a format that I can transmit to the Eltek charger. Quote Link to comment Share on other sites More sharing options...
Jorge L. Posted May 23, 2023 Share Posted May 23, 2023 Hi, I have a related question. When using a Axpert off-grid inverter, when you connect a generator, the inverter will bypasss it to the outllets and charge batteries, this make´s the need of a huge generator to support consumptions peaks. The ideal will be to have the generator charging the batteries and the inverter producing the AC current, this will let you charge with a smaller generator without going overloaded, but is not how it works. So, Someone knows how to turn avoid the bypass when a generator is connected. IF it´s possible. If it´s not, A parallel charger will be the option. I´m using Narada batteries that have their own BMS (they are connected to the inverter comunicating using "LIB" config), so they will protect themselves (same as Pylontech), Thank you! Quote Link to comment Share on other sites More sharing options...
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