hey guys!
with a little bit of discussion lately on desulphating batterys, i thought i would look into it a bit more as i am on the look out for some cheap sources for batterys.
what caught my attention was the quicky made xformer-bridge rectifier-capacitor type charger that Jerry is using.
well into the junk shed and dig out some parts :) i pulled out an old motor base, a 3 phase bridge rectifier, a 350va 220 volt isolation xformer, and 3 60MFD 370 volt capacitors. i will only be applying 120 volt to the xformer though.
this is what i threw together
this year i had to replace my driving lawn mower battery. it was a cheap wallymart $18 battery. it was made in 2004, so didn't last too long. i had tried charging it in the spring a few times with a 10 amp battery charger and also a newer shumaker battery charger. result was after sitting for 1/2 hour, it didn't even have the power to engage the solenoid on the starter. i tossed it beside the shed and left it there all year so far. i decided to try and charge that battery on the new home made charger. i took of the battery caps and found it full of water , right to the top. all the rain this year seemed to seep into the vents. no idea how diluted the acid is now. my cheap hydrometer has 4 balls in it, with each ball representing 25% of full charge. kinda crude, but good enough to have an idea of what the charge is in the battery. all cells had 2 balls floating, one cell had 1 ball floating (not good).
i first had 180 MFD of caps connected to the charger. it drew just a little over 10 amps. one of the cells would not bubble even after a 1/2 hour of charging. the xformer was getting quite hot, so i reduced the capacitor to just 60 MFD. with just the one capacitor, it draws about 2.5-2.6 amp. afew hours after, that one cell that would not bubble, started to bubble. i ran it till 7PM last night and found by then that all cells were bubbling equaly. i now had 3 balls floating in each cell and the 4th ball was just starting to rise. i tested the voltage this morning after sitting outside all night and it was 12.6 volt. i put it back on the charger for another 4 hours, let it rest for 2 hours. i then took a short piece of nichrome wire and shorted the 2 terminals. it got hot within seconds and could burn tissue paper to the touch. i then measured voltage and found it to be 12.8 volt. very encouraging and i shall see what it measures tomorrow morning. each cell now has all 4 balls floating in the hydrometer.
this is the battery
2 years ago i was given a 12 volt auto battery. it is one of those capless ones they vent with a hose running to outside of car. it was no good then and i had tried to charge it without success. i just used it as a load cell when testing out a genny. it was frozen over the winter also and left outside. case never cracked though.
there was no way to see inside, so i took a hack saw and cut off 1/2 the top of the battery. 2 cells were very low, but the plates were not exposed. none of the balls would float in the hydrometer. the acid was now full of plastic saw dust from me cutting the top off. i poured it all into a bucket and strained it through an old towel. it removed most of the saw dust and i poured it back into the battery.
here is the battery
picture of just 2 cells
i wanted a little more charge from the charger, so i connected up 2 microwave xformers like Jerry had just spoke of in a recent diary. with the 180 MFD of capacitors, it put out 10 amp of charge current. after 1/2 hour of running, i found the primary coil in the output xformer was getting very hot. i reduced the capacitors to 120 mfd and the current now was 6 amp.
for the first 1/2 hour, all cells except 2 were bubbling very hard. the first 2 closest to the negative post were basically doing nothing. none of the balls in the hydrometer were floating at all. that is when i reduced the capacitors.
if the xformer seems to stay not quite as hot as it was, i am going to leave it on all night. it sits outside on the picnic table. the battery is kind of useless now with the top cut off, but i wanted a good look inside and want to see what is going on as i attempt to charge/desulphate/rejuvinate this battery. LOL! its all in fun.
hope you enjoyed the post and will let you know what happens with this battery.
zubbly
