Hello David, This indication is a common effect when trying to charge sulfated negative plates. Working in a battery shop way back in the 50's, we used single 2 volt clear glass batteries call jars. A cell is actually part of the main battery case, a jar is the single container that slides into the battery case.
With a clear jar case, you can see several indications what is causing a problem. The bottom of the plates are kept off the bottom of the battery case, so as to allow room for the sulfate to build up before touching the bottom of the battery plates. When the build up starts to touch the plates which shorts the plate. As the sulfate touches the plates, it normally will clear the short with a small pop. Also the positive plate will lose the oxide from the pb+02 grid. The 02 is now in solution and could grow into long spikes shorting two plates. Charging the battery, the 02 spikes across two plates will also cause this popping noise. You can bring these cells back to a normal operation, but it is very time consuming. Just about impossible for a seal case battery box. This is way I like the separated jars, where I can remove the top, pull the plates and immersed the plates in a glass tank of distill water that sets on a vibrating table which removes all the sulfate and oxide particles. Now test the specific gravity of the electrolyte that was in that one cell. Lets say it reads 1.200 sg, we than mix up new 1.200 sg electrolyte and immersed the clean grids into the electrolyte allowing the top of the grids above the electrolyte. Check between each grid with a volt meter to see if any shorts are remove between any two grids. If a short is present, there will be no voltage indication. To repair this short, pull the grids out of the electrolyte and immersed in the cleaning tank again. After cleaning, place the grids on a glass plate. Now we start to remove the separators between each grid. This is done by pushing in a new separator which pushes out the old separator. If the short indication is still present, clean the old separator and use that one to push out the next one. This procedure will than clean the shorts or all the sulfate and 02 particles. Again do a final cleaning of these grids and place it back into the cell or jar. IMPORTANT - ALWAYS FILL THE CELL WITH THE SAME SPECIFIC GRAVITY ELECTROLYTE YOU TOOK OUT. If the cell had 1.200 sg electrolyte when you remove the plates, then you fill this cell with new 1.200 sg electrolyte, not 1.275 or 1.300. Why, because the plates still have the remaining electrolyte in it. You charge the cell which will released the remaining sq until it reaches 1.275 sg. If a person puts in 1.275 sq electrolyte cold, this cell will become specific gravity unbalance which will be too high in sg as compare to a low sq cell. This would be a good experiment project if you do not have anything else to do. Roland ----- Original Message ----- From: EVDL Administrator<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Tuesday, December 17, 2013 12:17 AM Subject: [EVDL] Noisy batteries I'm tinkering with a winter project for which I could use a little medium voltage DC, but not much current nor many amp-hours. I thought of some weary old 8v golf car batteries I've had sitting untouched and unloved in the garage for several years. They were pretty well clapped out, down to maybe 20-25 usable amp hours when I parked them there. I wondered if they might still have 5 or 10 amp hours in them even after sitting all this time. The electrolyte level was WAY low, below the tops of the plates. It took almost a gallon of water for 8 batteries, just to barely bring the level up above the plates. (Not a good sign already.) I connected them in series. The whole 64v nominal string read a little over 9 volts! But I connected a Fair Radio charger (mil-surplus charger, really just an unregulated adjustable voltage DC supply) with a 60 watt incandescent light bulb in series and cranked up the charger as high as it would go, 120 vdc. No indication on the ammeter. The bulb didn't light. I left it overnight. Lo and behold, the next morning, the bulb was lit, though not very brightly. I measured a bit more than 25 volts across the bulb on my cheapo Harbor Fright garage DMM. (Across battery and bulb I was seeing more like 160 volts.) The charger's ammeter still hadn't budged. Twenty-four hours more and the bulb had brightened. I now read 34 volts across it. So I thought I'd see what happened if I took the bulb out of the circuit. I cranked up the charger until its ammeter read about 1.5 amps. After a few minutes I heard a sizzling noise. So I shut down the charger and started popping cell caps. Found a cell that was steaming. Yep, that's the one. Bypassed its battery and tried again. This time, after a couple of minutes, I heard a distinct POP. Shut down the charger and checked cells again. Didn't see anything strange this time. Reduced the voltage and current. POP again. My worry is that I'm hearing little hydrogen explosions, possibly from a cell that's generating hydrogen and internal cell sparking from a partial short circuit. Is that possible? I'm not feeling brave enough to want to try charging with all the call caps off. I really don't want to lose my garage and/or my eyes. Any conjecture as to what caused the hissy-steamy cell? As to what's making that unnerving POP? Does the hydrogen/spark scenario make sense? What's to blame for this? Could it be months - or more likely, years - of sitting with lead (sulfate) plates exposed to the air? Does anyone really think there's any hope for these batteries? My inclination at the moment is to just haul them all to the recycling center, except that you never know when you might need a dead battery so you can avoid paying a core charge. So what do y'all think? Any hope? Or are they suitable just as dead weight and cores? David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/<http://www.evdl.org/help/> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/<http://www.evdl.org/help/> . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... 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