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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason


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About Macduffy

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    Durban, KwaZulu-Natal

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  1. Hi @Coulomb @Solo Following your advice I contacted the South African agent and he in turn got in contact with the OEM engineer. The engineer stated that the inverter follows a 2-step charge if it is above 12V and a 3-step charge if it is below 12V. I since reran the test and dropped the batteries down to 11.9V and then started the charge cycle, it went through the bulk charge stage and stayed at the absorption voltage for a number of hours and then finally entered the float stage. So this seems to have solved my problem, I wasn't draining the batteries low enough to enter the absorption stage. I have only tested this when setting 05 is set to AGM, which the agent advised. I am still to test it under the User Defined setting. I don't often drop the batteries to below 12V, so I may still keep the equalisation option active every few days/weeks just below the gassing voltage. I am still concerned I am only partially charging the batteries on the 2-step charge..... On another note I looked further into the batteries that I previously bought that went bad - the Omnipower (OPR120-12) ones which lasted just over a year. I was told that most of these are sold as new, however are actually second hand and are taken from battery banks. The guys keep the box and then repackage them. One of the signs to look for is a serial code sticker stuck to the top of the battery over the original serial number. As it turns out my Omnipower batteries has a different serial number stuck over the original serial number and some of the digits vary - so I suspect I may have been sold old batteries. The shop I bought them from has since gone out of business so no option for recourse. On my new Ritar batteries I checked the voltage when I bought then (>12.7V) and checked the date of manufacture from the serial number (Aug 2019) - hopefully it is enough of a check to ensure I bought new batteries this time.
  2. Hi Solo The measurements I posted are directly from the inverter, from the USB cable. I then use WatchPower to log the data. The readings on the Axpert display and the WatchPower readings should be the same. I have verified the Axpert display reading with a voltmeter, measured across battery terminals, and it is quite accurate - a difference in measurement +-0.05V. The Axpert reading tends to have more noise whereas the voltmeter provides a constant voltage across the batteries. Regards
  3. I called the supplier of the inverter today, he said that setting 05 should be on AGM and not User Defined. I reran the discharge/charge cycle with setting 05 on AGM and it did the exact same as before - the bulk charge stopped at 13.8V and skipped the absorb charge. I will contact him again tomorrow to see what else he can recommend, he was quite helpful. Thanks I have set it to 14.2 V for now. I will see what I can arrange to monitor them. The batteries are still very new, I have only cycled them around 2 or 3 times where they went straight to float charge. The rest of the cycles I have used the equalisation setting at the end to do the absorb charge. Hopefully no noticeable damage has been done.
  4. Hi Solo This is an expensive flaw in the Axpert Inverters. I can't believe that all the Axperts have this flaw, there must be thousands of them on the market. Whats common to our systems is no solar power. My inverter, as per above, reads 0A charging current when it is in the utility charging cycle; is there a flaw that it only reads for solar charging? So when solar is connected and in use the inverter then reads this as charging current and the minimum current of 4A is achieved and the inverter can then get to the absorption stage - but as Coulomb said this still doesn't explain why it doesn't reach the bulk charge of 14.7V when on utility. I also got caught by the battery low cutoff setting - battery suicide. My batteries are in parallel so I don't get the unequal charging issue.
  5. I thought this was weird, but i assumed it related to PV current only. I am not sure if I understand. The batteries are only in use when the mains is off, when mains is on then the batteries are bypassed and the load runs off mains power only. The batteries are only charged when mains is on, but at the same stage they have no load. So either mains is on and the batteries are being charged (20A for bulk charge) or mains is off and the batteries have a load of 10A (or whatever my power draw happens to be) but no charge. As per above comment, the charge light comes on immediately when main is switched back on after a discharge. The charge light is only off when i switch off mains power. Yes correct, It just maintains the battery in float mode at 13.7V. I increased the bulk charge voltage, setting 26, to 15.0V and reran the discharge/charge cycle, it made no difference and did the same as before (raw data here 20200216120042_Cycle.xls). The bulk charge was on for roughly 22min this time with the charge light flashing, the bulk charge still ended at the 13.8V mark. The same voltage drop occurred to 13.6V at the end of the bulk charge and then it moved up to the float at 13.7V which it then maintained. So roughly 20Ah out and then ((22/60)*20) and then around 7.3 Ah back into the battery? I have since activated the equalisation option, this worked and brought the batteries up to 14.3V for 60min as shown below (raw data here 20200216120042_Equalise.xls) I have set it to run every 4 days for now. Should I try and match the equalisation frequency to the battery cycling frequency - so after every battery discharge and charge I will then manually activate the equalisation (this may become tedious)? The problem with automating the equalisation frequency is that the power outages come in waves, we can sometimes have 3 months without any power failures and then we will unexpectedly have 15 of them in 2 weeks. An alternative approach is that I can set the equalisation setting to automatically happen once a day when we are having daily power outages and then when we are having months of no power outages I can change the equalisation frequency to once every 2 or so weeks? I have also placed a temperature sensor on top of the battery to better understand the temperature and variation. It consistently reads 27.5 to 30.5deg C, we are having hot days at the moment. The battery datasheet states Equalisation and Cycle Service: 14.6 - 14.8 V @ 25dec C, should this be disregarded? You have stated that 14.4V @25deg C is the gassing temperature, so at 30 deg C it changes to ~14.3V (which is the value you said I should use above). So for the moment i will maintain the equalisation at this 14.3V for 60min periods and maybe increase the voltage slightly in winter. Are there any clear signs that will let me know if I am overcharging or gassing the batteries? Will the temperature of the batteries rise, or will they make a noise? Thanks
  6. I didn't pay too much attention to the charging cycle on the previous batteries. I only monitored the voltage during discharge, so I cant confirm if it ever reached absorb voltage. Yes, that happened was over a 1 hour loadshed. The inverter is plugged directly into a plug socket running on mains/Eskom. I changed setting 02 to 20A, I then unplugged the inverter from the wall to test it on another discharge/charge cycle. At this stage the charge light turned off. I drew a more or less constant load of 100W (active power) over a 2.5hour period. The discharge current from the batteries was more or less constant at 10A over this period, so i estimate I drew ~25Ah. The batteries ran down to around 12.4V, and then I switched the power supply to the inverter back on which started the charging cycle. The charge light started flashing and the voltage went back up to 13.8V within 43 minutes, the inverter then switched straight to float mode and the charge light stayed on constantly. It seems to have once again skipped the absorb stage. The discharge/charge cycle is shown below, raw data is here 20200214222155.xls. Would changing setting 16 from SNU (Solar and Utility) to CUt (Utility only) make any difference and maybe initiate the absorb charge? Thanks for your time.
  7. Hi there I have installed a UPS system at home due to loadshedding and periodic and occasionally regular electricity supply failures from Eskom. The loadshedding is 2 hours at a time and generally not more than 4 hours in a day, and our power failures on average are resolved within 4 hours (rarely going above 8 hours). I am essentially looking for 600Wh to 800Wh of power in which I can run my alarm system, gate motor, TV, lighting, Wifi, laptop and phone chargers (not all at once). I typically manage the load when the power is off and try not to exceed 150W for loadshedding and 80W for power failures where the outage time is unknown. To meet the above requirements I installed the back up system in April 2018 with a FullCircleSolar 1kVA/1kW inverter (FCS-1K-VP-1000W) (I understand that this is Voltronic?); and 2 x Omnipower AGM 120ah (OPR-120) (datasheet here OmniPower_OPR120_Datasheet.pdf) batteries . The system was designed on running to between 30% and 50% DOD. There are no solar panels connected to the system and it is installed in an enclosed room in my house (temp 15 - 25 dec C). At the time I had little to no knowledge of inverters/batteries, and kept the default settings on the inverter (AGM charge settings and a DC cut off of 10.5V). After 14 months of operation, and approximately 40 power outages, the batteries started to lose capacity, I didn't track to voltage too closely but they likely discharged as low as 11.3V for 2 or 3 times (a few prolonged outages). I guess I took the battery data sheet a bit too literally - I thought I could run them to 80% DOD and get 1000 cycles... Eventually the batteries would charge to the float voltage but when discharged they only lasted 60min on around 20W power draw until error 04 would be displayed and it shut off, that said, when I disconnected the charged batteries and left them for 24 hours they read a voltage of 12.8V. Based on what I read on this forum the above means the batteries are toast.?..?. I have since replaced the Omnipower batteries with 2 x Ritar DC12-100 AGM (datasheet here DC12-100.pdf) batteries from Mantech, I read generally positive reviews about these batteries and they are well priced. I am aiming to get 5 years out of the batteries so I am now extra cautious and have the following settings on the inverter: Program Description Selectable option 01 Output source priority Ut1 02 Maximum charging current 30A 03 AC input voltage range UPS 05 Battery type USE 06 Auto restart when overload occurs Restart disable 07 Auto restart when over temperature occurs Restart disable 09 Output frequency 50Hz 11 Maximum utility charging current 20A 12 Setting voltage point back to utility source 11.5 13 Setting voltage point back to battery mode 13.5 16 Charger source priority CUt 18 Alarm control bON 19 Auto return to default display screen ESP 20 Backlight control LON 22 Beeps while primary source is interrupted AON 23 Overload bypass Disable 25 Record fault mode FEN 26 Bulk charging voltage 14.7 27 Floating charging voltage 13.7 29 Low DC cut-off voltage 12.0V 30 Battery equalisation Disable 31 Battery equalisation voltage 14.6V 33 Battery equalised time 60 34 Battery equalised timeout 120 35 Equalisation interval 30d 36 Equalisation activated immediately Disable Are these settings correct for the given battery? I am also paying closer attention to the discharge/charge cycle of the batteries, and I am concerned that the inverter is skipping the absorb stage of the charge cycle (referred to elsewhere in the forum as premature float bug with the Axpert inverters). The below is a discharge/charge cycle for a recent loadshed, and when charging it goes directly to the float voltage of 13.7V. The full excel sheet for this cycle is here 20200211211115.xls. Is this what I think it is, is the absorb stage being skipped and the batteries only partially charged, could this be partly responsible for the demise of my previous Omnipower batteries? Alternatively am I not discharging the batteries enough to trigger the absorption stage? I am concerned I am going to destroy these Ritar batteries as well. Should I try and update the firmware and also risk bricking the inverter, my version is U1.08.33? Also I saw on another thread that someone has sort of overcome premature float problem by activating the equalisation setting for the AGMs - 2 days a week at 14.3V for 120minutes. Is this a better solution or can I damage my AGMs from this? The is what the manual states the charging cycle for the inverter should follow the below: Another question on the active power and the apparent power, my understanding is that the ratio of these two gives the power factor. In some instances it goes above 2, which you will see on the raw data I attached above. However, when I unplug my gate motor and alarm it goes down to 1. Is there anything that can be done to correct this, or is it just "it is what it is"? Thanks Liam


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