I have had success with putting together either (3, for 24 v systems) or (6, for 48 v systems) 9 V Duracell batteries to jump start off grid OutBack systems when their battery banks have been unattended for too long, last one sat for a year & a half due to the covid before the owners got back into their remote cabin. The 24 v battery bank measured ~ 4 volts. I was able to re-awaken the OB MX60 and FX2524 long enough to have the solar kick in and start charging the system, keeping the inverter on long enough to get a gen set to engage recharging.
What is the thought on using 9 v batteries to bring up the caps on the Magnum’s during initial startup? Chris Worcester Solar Wind Works NABCEP PV Installation Professional Cell 530-448-9692 www.solarwindworks.com ch...@solarwindworks.com From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of Jeff Clearwater Sent: Monday, June 14, 2021 9:01 AM To: drake.chamber...@redwoodalliance.org Cc: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] Magnum MM1524AE rebuild? oh and of course I put an inline fuse in the circuit. The current that flows of course will be dependent on battery voltage and resistor ohms. So with a 48 VDC pack you could go up in resistance - just figure per ohm - volt - amp formulas/calculator here. <http://www.sengpielaudio.com/calculator-ohm.htm> With less than 5 amps - you'll get a nice ramp up fill of your caps on most inverters we use in the industry. Hope that helps! Jeff Clearwater Village Power Design Jeff Clearwater <mailto:je...@villagepowerdesign.com> June 14, 2021 at 8:53 AM Hi Drake, So it's simply a momentary bypass circuit from the Load side to the Line side of your Main Inverter Breaker. So from battery side of inverter to momentary on-off switch to resistor to inverter side of breaker. I used a 25 Ohm 50 watt resistor. this one <https://www.amazon.com/YiePhiot-Resistor-Aluminum-Wirewound-Doorbell/dp/B07MW4VHDB/ref=sr_1_13?dchild=1&keywords=YiePhiot&qid=1623685581&sr=8-13> and this nice metal screw-terminal momentary on-off switch this one <https://www.amazon.com/Momentary-Waterproof-Stainless-Terminal-warranty/dp/B079HR5Q4R/ref=pd_sbs_1/142-3113942-9020237?pd_rd_w=dHOiq&pf_rd_p=a5925d26-9630-40f3-a011-d858608ac88b&pf_rd_r=WSD3157P3TEAB0M4Z6PR&pd_rd_r=ab809190-b332-4f06-952b-369bf1c6a51c&pd_rd_wg=qD1Vl&pd_rd_i=B079HR5Q4R&psc=1> With a Magnum MS4024 PAE on a 10 KWH LiFePO4 pack - when I push the switch initially about 2 amps flows - I've found I need to hold it for about 8 seconds for the current to drop off to about .4 amps - then when I flip the 175 AMP main DC inverter breaker - there is little additional current that flows into the inverter caps - no sparks and my BMS doesn't shut down due to overcurrent fault. Hope that helps! Best, Jeff _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org <mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org drake.chamber...@redwoodalliance.org <mailto:drake.chamber...@redwoodalliance.org> June 11, 2021 at 12:27 PM Hello Jeff, That sounds really useful. How do you wire this? Where do you get the momentary switch? Thanks, Drake --- On 2021-06-09 12:13, Jeff Clearwater wrote: Hey Dave and Wrenches, This is why now I always install a pre-charge circuit for Magnum's and other inverters - especially on a Lithium pack with a BMS. A momentary on-off switch and 50 watt 20 ohm resistor - $20 worth of parts = a lifetime of less stress on main breaker - inverter caps and battery BMS. I recommend it for any inverter over 2 KW. Many LiFePO4 BMS's will shut down when sensing that much inrush so it's a must on many systems. Best, Jeff Clearwater Village Power Design palumbo1...@gmail.com <mailto:palumbo1...@gmail.com> June 8, 2021 at 6:01 AM Is a Magnum MM1524AE inverter/charger repairable and if so by whom? It failed after being reconnected to a battery bank, the typical small spark at the battery terminal when being reconnected was accompanied by a popping sound in the Magnum. Killed the Magnum. Dave Palumbo Hyde Park, VT _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org <mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org <mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org Jeff Clearwater <mailto:je...@villagepowerdesign.com> June 9, 2021 at 9:13 AM Hey Dave and Wrenches, This is why now I always install a pre-charge circuit for Magnum's and other inverters - especially on a Lithium pack with a BMS. A momentary on-off switch and 50 watt 20 ohm resistor - $20 worth of parts = a lifetime of less stress on main breaker - inverter caps and battery BMS. I recommend it for any inverter over 2 KW. Many LiFePO4 BMS's will shut down when sensing that much inrush so it's a must on many systems. Best, Jeff Clearwater Village Power Design _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org <mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org Jeff Clearwater <mailto:je...@villagelab.net> June 9, 2021 at 9:12 AM Hey Dave and Wrenches, This is why now I always install a pre-charge circuit for Magnum's and other inverters - especially on a Lithium pack with a BMS. A momentary on-off switch and 50 watt 20 ohm resistor - $20 worth of parts = a lifetime of less stress on main breaker - inverter caps and battery BMS. I recommend it for any inverter over 2 KW. Many LiFePO4 BMS's will shut down when sensing that much inrush so it's a must on many systems. Best, Jeff Clearwater Village Power Design palumbo1...@gmail.com <mailto:palumbo1...@gmail.com> June 8, 2021 at 6:01 AM Is a Magnum MM1524AE inverter/charger repairable and if so by whom? It failed after being reconnected to a battery bank, the typical small spark at the battery terminal when being reconnected was accompanied by a popping sound in the Magnum. Killed the Magnum. Dave Palumbo Hyde Park, VT _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org <mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
