Thanks Vasile ! Yes they are 44Ah, and my DMM says I reach more than 3A even if I charge all 10 of them in series, sometimes however they do get above 14V I found the note about pulse charging at a site that said battery University I think, I was looking into selecting replacement Batteries for my 36V E-Bike, but it might be that this comes form people that want to sell chargers... By the way how do I know my 'battery nominal current' ? My usual discharge is minute, a few energy saving light bulbs that draw ~210mA each or rarely a vacuum or a angle grinder, and the standby mode Rabbit protection electrifying my cages against ground so the dogs know I'm serious! The other day I did my first battery based welding, (which is excellent) using 2 parallel Banks of 3 Batteries in series (36V)! On Thu, Mar 26, 2009 at 10:03 AM, Vasile Surducan wrote: > On 3/25/09, Tobias Gogolin wrote: > > Hi happens that I find the piclist to be the community of the fittest > > electronic engineers that I know on the web, that's why I ask here and > not > > on some of grid living list... > > > > I may have mentioned before that I use 10 pc. 12V car batteries at my of > > grid ranch, and that I charge those using a simple rectifier, either > Bridge > > from 120V AC or 2 diodes using half of each of the 2 120V outlets around > the > > center of my generators 240 V AC output (I do that to reduce the chance > of > > any one of the automatic breakers of the 2 120V circuits from tripping). > > > > This seems to work quite good, but I just read that it is not advisable > to > > charge Car batteries on pulse current, > > Maybe you should start first by defining the amount o energy you need > for charging. > Assuming your car batteries have say 44Ah (but could also have 80Ah as > well) if you need to fast charge those batteries, you will need 140V > and 4...10A. I don't know where you read that is not advisable to > charge acid Pb batteries with pulse current, but you probably know > that a car battery acts like a huge capacitor. As long the charging > current is less than 10% of the battery nominal current and the > maximum voltage per one battery is less than 14V at full charge , it's > fine with current pulse charging. > > Vasile > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- Tobias Gogolin Tel. Movistar (646) 124 32 82 Tel. Telcel (646) 160 58 99 skype: moontogo messenger: usertogo@hotmail.com You develop Sustainable Ranch Technology at http://tech.groups.yahoo.com/group/SURA-TECH an Open Source Electric Motor/Alternator at http://groups.yahoo.com/group/Performance_Axial_Flux and an Open Source Motor Controller at http://groups.yahoo.com/group/GoBox -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist