June 26, 20223 yr Hi all, Bit of a strange thing happened the other week with my March 2019 RCT Axpert 1K 24v and Hubble S-120's; only getting around to looking at the problem now - not sure if it's just bad luck, murphy's, or if there is something wrong with Hubble's charge settings, or Axpert compatibility. I had the Axpert 1K initially connected to 2x OPR120-12 OmniPower 12V 120Ah AGM batteries, in series, to give the 24v configuration (no solar involved) - all worked well with the inverter settings set to 20A charge, 13.7v float charge and 14.4v cycle charge per the battery spec given to me. The OP's were 3-odd years old and not really holding their charge any more, so I dove in and replaced them with 2x Hubble lithium S-120's. The relevant Axpert inverter settings were updated to the given Hubble charge specs, being 20A charge, 12.8v nominal, 14v float charge, 14.4v cycle charge and 11.2v cut-off per 12v battery - Hubble confirmed (as did their leaflet/manual) that for a 2-battery 24v series setup, I simply double the "v" figures, which made sense. So the inverter settings were 20A charge, 25.6v nominal, 28v float and 28.8v cycle charge. The first few bouts of 2hr loadshedding were fine and all seemed to work well, although the inverter seemed to be charging for much longer on the Hubble's and never hit the 28v/28.8v mark at all on float/bulk charges. On the next loadshedding, about 30 mins in, there was suddenly a strong electrical burning smell coming from the inverter; no fuse pop, smoke or anything - switched it off, pulled the Keto battery disconnect and unplugged everything. The inverter was not at all hot, neither were the batteries or cables. Batteries looked and smelled fine, still had 13.0v charge each. The inverter is apparently knackered, but not sure from what? No dust, dirt or miggies in the case, nothing looks popped or burnt on any of the wires or boards. Could the Hubble's themselves or their charge settings have caused this? If so, why? Are the charge figures too high for a 12.8v nominal? Who knows, maybe the inverter just blew for no specific reason - just trying to understand the problem to avoid it again - going to try have the inverter looked at and repaired, else will have to replace it - just don't want a similar issue with a new inverter blowing due to the Hubble settings Here's the Axpert sticker specs:
June 26, 20223 yr 9 minutes ago, HowardB said: Hi all, Bit of a strange thing happened the other week with my March 2019 RCT Axpert 1K 24v and Hubble S-120's; only getting around to looking at the problem now - not sure if it's just bad luck, murphy's, or if there is something wrong with Hubble's charge settings, or Axpert compatibility. I had the Axpert 1K initially connected to 2x OPR120-12 OmniPower 12V 120Ah AGM batteries, in series, to give the 24v configuration (no solar involved) - all worked well with the inverter settings set to 20A charge, 13.7v float charge and 14.4v cycle charge per the battery spec given to me. The OP's were 3-odd years old and not really holding their charge any more, so I dove in and replaced them with 2x Hubble lithium S-120's. The relevant Axpert inverter settings were updated to the given Hubble charge specs, being 20A charge, 12.8v nominal, 14v float charge, 14.4v cycle charge and 11.2v cut-off per 12v battery - Hubble confirmed (as did their leaflet/manual) that for a 2-battery 24v series setup, I simply double the "v" figures, which made sense. So the inverter settings were 20A charge, 25.6v nominal, 28v float and 28.8v cycle charge. The first few bouts of 2hr loadshedding were fine and all seemed to work well, although the inverter seemed to be charging for much longer on the Hubble's and never hit the 28v/28.8v mark at all on float/bulk charges. On the next loadshedding, about 30 mins in, there was suddenly a strong electrical burning smell coming from the inverter; no fuse pop, smoke or anything - switched it off, pulled the Keto battery disconnect and unplugged everything. The inverter was not at all hot, neither were the batteries or cables. Batteries looked and smelled fine, still had 13.0v charge each. The inverter is apparently knackered, but not sure from what? No dust, dirt or miggies in the case, nothing looks popped or burnt on any of the wires or boards. Could the Hubble's themselves or their charge settings have caused this? If so, why? Are the charge figures too high for a 12.8v nominal? Who knows, maybe the inverter just blew for no specific reason - just trying to understand the problem to avoid it again - going to try have the inverter looked at and repaired, else will have to replace it - just don't want a similar issue with a new inverter blowing due to the Hubble settings Here's the Axpert sticker specs: Not sure why the inverter went. I would not have taken the Hubble to 28.8V.That is where the BMS would cut them off. This I would try to prevent. I use 27.8V normal charge. At around 27.4V the Hubble do not accept much charge as the current drops of to below 3A. Thus indicating they are nearly full. 27.4V is what I float mine and they give me more capacity that the spec. I cut them off at 24.5-25V. Yes the high level of charge at 28.8V is the reason you see they take so long to reach that level. Just my 2c on my pairing of Hubble and Axpert.
June 26, 20223 yr Author 6 minutes ago, Scorp007 said: Not sure why the inverter went. I would not have taken the Hubble to 28.8V.That is where the BMS would cut them off. This I would try to prevent. I use 27.8V normal charge. At around 27.4V the Hubble do not accept much charge as the current drops of to below 3A. Thus indicating they are nearly full. 27.4V is what I float mine and they give me more capacity that the spec. I cut them off at 24.5-25V. Yes the high level of charge at 28.8V is the reason you see they take so long to reach that level. Just my 2c on my pairing of Hubble and Axpert. Many thanks! The voltages did seem a bit on the high side, even though Hubble said they were the recommended, weird. Will report back once the inverter is sorted and will try those lower settings 😉
June 26, 20223 yr 7 minutes ago, HowardB said: Many thanks! The voltages did seem a bit on the high side, even though Hubble said they were the recommended, weird. Will report back once the inverter is sorted and will try those lower settings 😉 Good. I have heard that it is indicated to take them to 14.4V to enable balancing but I have never got them there. I use 2 voltmeters for each battery and they are never out by more than 0.1V like now. If it gets to 0.2V I will manually charge 1 or discharge the other. Mine have been running for 7 months. Edited June 26, 20223 yr by Scorp007
June 26, 20223 yr Author 4 minutes ago, Scorp007 said: Good. I have heard that it is indicated to take them to 14.4V to enable balancing but I have never got them there. I use 2 voltmeters for each battery and they are never out by more than 0.1V like now. If it gets to 0.2V I will manually charge 1 or discharge the other. Mine have been running for 7 months. Great, thanks - I have a few spare voltmeters and will add them to monitor the difference.
August 5, 20223 yr Good morning What settings you ended up using for 24V with S-120 Hubble batteries?
August 5, 20223 yr 6 hours ago, Tshepo said: Good morning What settings you ended up using for 24V with S-120 Hubble batteries? I use 27.6V with a cut out at 25V when discharging on the S-100 batteries.
August 5, 20223 yr On 2022/06/26 at 3:55 PM, HowardB said: Great, thanks - I have a few spare voltmeters and will add them to monitor the difference. Do a cross check on actual battery voltage versus what the Inverter reports. I have found up to 0,7V difference, where the Inverter states 53,6V Battery voltage and the BMS is maybe at 52,8V. I then did a third check with a Fluke and that is even lower at 52,6 to 52,7V Yes, I know mine is a 48V system. Just double checking the real voltages will also give you peace of mind.
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