Same here, when I first installed my 312V pack (26 series 12V batteries) in my S10 US Electricar, I wanted to give them some charge since it had been a couple months since I ordered those batteries. I had an old analog meter that I bought from my saved allowance money somewhere in 1980 or so and after checking the pack voltage (resting around 320V and the output from a bridge rectifier and buffer cap on 240VAC input (around 340V unloaded) I started hooking them up together. Apparently I got confused because when I decided to close the loop with my multimeter set to Amps to verify how fast it would charge, there was a flash and a loud BANG, contact spots were vaporized and the traces in my old trusty multimeter were deposited against all other surfaces inside the meter, from shorting it across 600+VDC. Obviously it never worked right after that (even the V-measurements were totally off, probably due to burned traces or deposits) so after that time, I always check the voltage that I am connecting to make sure they are polarized the same way, not opposite! In your case, measuring from frame (not battery post) would have given you a negative reading which could have alerted you to the mistake. I hope the expensive parts (controller and such) are protected against polarity reversal.
Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.info Skype: cor_van_de_water XoIP: +31877841130 Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 -----Original Message----- From: EV on behalf of Peter Gabrielsson via EV Sent: Mon 7/6/2015 12:02 PM To: Robert Bruninga; Electric Vehicle Discussion List Subject: Re: [EVDL] Polarity Reversal (duh) I hooked up a power-supply to my 120V pack once, backwards. The arc was bright, the bang was loud, leads were vaporized. On Mon, Jul 6, 2015 at 9:35 AM, Robert Bruninga via EV <[email protected]> wrote: > Sharing my mistakes so others can avoid them. > > > > Wife was outta town so I hauled over the Honda Civic DC conversion project > to the driveway. Didn't really have time to mess with it (day job bekons > 12,14, 16 hrs a day and all that). > > > > So I plugged in the charger (hasn't been plugged in in 6 months). Was > gonna keep an eye on it and forgot. Got to work, remembered, and 2 hours > lateer got home to a melted extension cord. (At least now I will be more > tolerant when the wife insists on going back home because she may have > forgotten the iron). > > > > So then I switched to a conventional charger to top off the 12v accessory > battery. It was completely dead. > > > > Came home (again around 10PM) and all looked ok. Battery was fully > charged. > > > > This morning (realizing wife is coming home tomorrow), its time to move the > bucket of bolts back to its hiding place (which is up hill). Turned it on > and the only thing that worked was the Windshield Wipers (going backwards). > and lights. Hummh. > > > > Darned if I did not charge the 12v battry BACKWARDS. Why did I do that? > Well, the battery has a big round RED dot sticker (to show the date of > purchase) and it is stuck on the battery right next to the negative > terminal. > > > > And now you know the rest of the story. well, except that the controller > and everything else electronic in the car is probably shot. And we wont > know till later tonight how I get the 3000 lb car up the hill to its hiding > place. > > > > Don't do this at home. > > > > But you ask, "But modern battery chargers will not charge a dead or > reversed battery". No, so I paralleled it with a jump-start battery to get > it started. (Lead Acid batteries have the same LEAD on both the positive > and negative terminals. The polarity is deermined by how you charge it!) > > > > The windshield wipers comment was a trick question just to see if you were > paying attention. > > Bob > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150706/d41aecd2/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- www.electric-lemon.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150706/2f347da4/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
