kwagga23 Posted May 9, 2023 Share Posted May 9, 2023 I went ahead and bought a Must brand 1kw inverter from GW. They gave me a bunch of settings to adjust: 2: AC input range = UPS 14: battery type = USE 17: bulk charging voltage = 14 18: floating charging voltage = 13.5 19: cut off = 11.2 Its on a hubble s100 lithium pack. The chg LED never stops blinking when on mains power, and the fans keep turning on with about a 2 minute gap in between. The screen does show bypass is on from mains to load. BATT is at 13.7v. Is this normal for the CHG led and fans? Added an image of the screen and the flashing orange LED. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted May 9, 2023 Share Posted May 9, 2023 54 minutes ago, kwagga23 said: I went ahead and bought a Must brand 1kw inverter from GW. They gave me a bunch of settings to adjust: 2: AC input range = UPS 14: battery type = USE 17: bulk charging voltage = 14 18: floating charging voltage = 13.5 19: cut off = 11.2 Its on a hubble s100 lithium pack. The chg LED never stops blinking when on mains power, and the fans keep turning on with about a 2 minute gap in between. The screen does show bypass is on from mains to load. BATT is at 13.7v. Is this normal for the CHG led and fans? Added an image of the screen and the flashing orange LED. My take on this is the inverter is trying to reach 14V but does not reach that level. Currently the battery is still on 13.8V. Try setting bulk to 13.8V and see if the charging stops. If it does you can decide if you set it back to 14V. Charging from grid or solar does cause 1 or 2 fans to run. This is on my Axpert clone. Quote Link to comment Share on other sites More sharing options...
kwagga23 Posted May 10, 2023 Author Share Posted May 10, 2023 (edited) 7 hours ago, Scorp007 said: My take on this is the inverter is trying to reach 14V but does not reach that level. Currently the battery is still on 13.8V. Try setting bulk to 13.8V and see if the charging stops. If it does you can decide if you set it back to 14V. Charging from grid or solar does cause 1 or 2 fans to run. This is on my Axpert clone. Ill give it a shot quick with a 13.8 bulk Edited May 10, 2023 by kwagga23 Quote Link to comment Share on other sites More sharing options...
kwagga23 Posted May 10, 2023 Author Share Posted May 10, 2023 50 minutes ago, kwagga23 said: Ill give it a shot quick with a 13.8 bulk No luck, same thing. I did notice next to the battery indicator is shows SLA. Should it not be LI? Since this is a lifep04 battery? Quote Link to comment Share on other sites More sharing options...
kwagga23 Posted May 10, 2023 Author Share Posted May 10, 2023 I also noticed another thing. The inverter makes a very feint squaling and sliight ticking noise when on AC and bypass mode keeping the battery on float. Just a byproduct of a cheaper inverter? This and the constant charging led flash is my only concerns. Sorry for all the questions. Very new to the backup power space. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted May 10, 2023 Share Posted May 10, 2023 13 hours ago, kwagga23 said: No luck, same thing. I did notice next to the battery indicator is shows SLA. Should it not be LI? Since this is a lifep04 battery? When using lithium you must set the battery type as USR. The problem is SLA is seen as lead acid and the inverter is trying to charge to reach about 14.4-14.6V. This could be the reason why it does not stop charging. zsde 1 Quote Link to comment Share on other sites More sharing options...
Timbo_vb Posted August 21, 2023 Share Posted August 21, 2023 I have a similar issue with the 5kw 48v model and a pylontech lithium battery - nothing I have tried has stopped the charge indicator. Although I don't think it has any real world impact as the battery seems to stop accepting charge once its full according to the amps display and the battery LEDs Quote Link to comment Share on other sites More sharing options...
meetyg Posted August 21, 2023 Share Posted August 21, 2023 (edited) I have a MUST 3K 24v. I currently don't have my PV connected, so only using Utility charging so far. I am banging my head against the wall trying to get Lifepo4 battery charging correct, but each setting has its downsides: USE: Basically its similar to AGM or SLA, but never achieves bulk/absorption voltage. This could be due to the "premature float bug" as in some Axperts and clones. But from what I've read, it should not affect Utility charging, but on my MUST it does. So basically it sits on float voltage. After that, it depends what output priority you are using. If using it as a UPS (Utility only, battery as backup), it seems to always float. LI: This is able to achieve bulk/absorption voltage, but now it runs this cycle forever (as far as I've seen). So it like floats at the higher voltage, forever. If the battery will accept it, current will still flow. Charging doesn't stop. Another oddity is that the manual says that bulk/float voltages can only be set via USE battery type, but LI also seems to abide by these voltage settings. It seems like using these MUST inverters as a UPS only device with Lithium batteries isn't optimal. If you run SBU, it will start to drain the battery untill "back to grid" voltage, but again it won't go into bulk with USE battery type. I would expect LI setting to actually stop charging when a certain amount of charge current is reached (AKA "tail current") as recommended by Lifepo4 battery manufacturers. BTW, the orange/yellow CHG light is not only to indicate charging, but also discharging, as the manual states (differs from Axperts/Voltronic clones). Edited August 21, 2023 by meetyg Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted August 23, 2023 Share Posted August 23, 2023 On 2023/08/21 at 10:12 PM, meetyg said: I have a MUST 3K 24v. I currently don't have my PV connected, so only using Utility charging so far. I am banging my head against the wall trying to get Lifepo4 battery charging correct, but each setting has its downsides: USE: Basically its similar to AGM or SLA, but never achieves bulk/absorption voltage. This could be due to the "premature float bug" as in some Axperts and clones. But from what I've read, it should not affect Utility charging, but on my MUST it does. So basically it sits on float voltage. After that, it depends what output priority you are using. If using it as a UPS (Utility only, battery as backup), it seems to always float. LI: This is able to achieve bulk/absorption voltage, but now it runs this cycle forever (as far as I've seen). So it like floats at the higher voltage, forever. If the battery will accept it, current will still flow. Charging doesn't stop. Another oddity is that the manual says that bulk/float voltages can only be set via USE battery type, but LI also seems to abide by these voltage settings. It seems like using these MUST inverters as a UPS only device with Lithium batteries isn't optimal. If you run SBU, it will start to drain the battery untill "back to grid" voltage, but again it won't go into bulk with USE battery type. I would expect LI setting to actually stop charging when a certain amount of charge current is reached (AKA "tail current") as recommended by Lifepo4 battery manufacturers. BTW, the orange/yellow CHG light is not only to indicate charging, but also discharging, as the manual states (differs from Axperts/Voltronic clones). Without PV it is trying to use battery power and charge AGAIN as per SBU. This is where one uses Util as priority and not SBU. This keeps the battery full as one would expect when used as a UPS. Battery is then charged and ready for LS. Charging is not ideal even when using PV. Not really just the bug on 24V models. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.