I picked up an unused but obsolete Brusa DC-DC power supply some years ago from Ebay. The manual from Brusa recommended that as its parasitic current was so low, you could dispense with a 12v battery and leave it online 24/7. I have never seen this option since on any DC-DC converter or on any commercially available EV as they all still seem to be wedded to the old limited life Pb technology for controls. It would be one heck of a weight saving to dispense of the 12v battery.
From: Roland via EV <ev@lists.evdl.org> To: Willie2 <wmckem...@gmail.com>; Electric Vehicle Discussion List <ev@lists.evdl.org> Sent: Monday, 6 June 2016, 15:03 Subject: Re: [EVDL] 12v tales A dead 12 volt battery is the problem when you have your control circuits in your EV run by 12 volts. My first EV that I received back in 1976 and still have it today, uses LINE voltage to run all the control circuits. LINE voltage is the same voltage as the main battery. Some control circuits in commercial power devices may use a lower control voltage, but this lower voltage is still control by the LINE voltage using a transformer. My EV control voltage was ran off a Honey Well motor generator that was power by the main 180 V battery. On dash control high voltage switch allow to turn on the ignition/start circuits to start the motor generator. This also power the power steering pump that also power the hydro boost braking system. The motor generator also provided 12 to 16 volts DC which was control by a standard 12 volt regulator that is use on 12 volt generators. I have replace this 12 volt control system with a Delco Inverter Alternator that is used on ambulances that provides both 12 to 16 V regulated and at the same time provide 120 volt 60 hz 5kw for my electric heaters, pumps, and fans. Use a 12 volt deep cycle battery that have run for about 10 years. Turn off the DC-DC converters and only used them for back up. If the DC-DC converters fail, I have a back up for them which is a portable 12 volt power pack which I only use one time. Roland ----- Original Message ----- From: Willie2 via EV<mailto:ev@lists.evdl.org> To: Electric Vehicle Discussion List<mailto:ev@lists.evdl.org> Sent: Sunday, June 05, 2016 7:20 PM Subject: [EVDL] 12v tales I was CONSTANTLY being stranded in my conversions due to dead 12v. Mostly, from dead DC-DCs. I had GaryK, against his advice, rig a jumper from 4 LFP cells to the lead 12v. Dead 12v? Install the jumper and drive home. Worry about the imbalance later. Once, when my DC-DC was not working, I installed a pair of golf cart batteries in the passenger foot well. I've run the 12v down on my first imiev twice. Both from inadverntly leaving the key on. For those not familiar with imievs, their idiotic design forces one to twist the key against a spring to "crank the engine". Having the key on runs accessories but not the DC-DC. The Tesla has not stranded me with a dead 12v. It warns of impending failure. I'm on my 3rd lead 12v in the Tesla. I have a lithium 12v ready to go in for the 4th. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20160606/75b81d66/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20160606/f80fa676/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)