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joe csuti 03-05-2013 04:37:55 70.111.203.134 Report to Moderator	As a follow up on inline diode charging system,the DC voltage output is usually 1.1-1.5v lower than AC stator output,this is due to internal voltage drop in diode,most 1.5-5A charging systems are unregulated,the actual DC charging voltage/current is determined by specific gravity/resistance of acid in battery as this changes with level of battery charge & condition of battery cells as acid acts as a half fast regulator for alt output,when battery new & all cells in good condition acid limits voltage/current charge to battery,as battery ages & cell(s) get weak due to internal breakdown of cell plates & cell(s) can't accept a full charge the gravity/resistance of acid changes along with AH capacity of battery,this will allow a higher voltage/current flow to battery up to max voltage/current rateing of charging system,in some cases it may blow the inline diode. The major problem with an unregulated system is it tends to shorten battery life due to overcharging as battery being charged all the time,many tractor mfg will spec DC alt output to 3-5A,if tractor has an electric pto they will install a dropping resistor on pto sw to limit charge voltage/current to battery when pto off,then resistor is bypassed when pto turned on to provide max voltage/current to clutch/battery or if mower manual engage they will install a current limiting resistor in wiring harness/at ign sw to limit max charge current to battery. [Reply]   [No Email]
Whizkidkyus 03-05-2013 08:11:49 64.130.151.65 Report to Moderator	Re: Charging Coils For Small Engines in reply to joe csuti, 03-05-2013 04:37:55   So does that mean that it's ok to charge a 12 volt battery , no matter the batterys age or condition , with 30 volts DC, regardless if it's comming from a regulated or not or a full or half wave bridge source ? Thanks, Whizkid [Reply]  [No Email]
joe csuti 03-05-2013 13:19:28 70.111.202.222 Report to Moderator	Re: Charging Coils For Small Engines in reply to Whizkidkyus, 03-05-2013 08:11:49   NO-IT IS NOT ALRIGHT to charge a 12v battery with 24-30V DC source regardless if regulated/unregulated,doing so can cause battery to boil & possibly explode. As Hal said normal charging voltage is 14-14.5v for a regulated system & 14-15.5v for an unregulated system,normal charging voltage for 12v lead acid batteries is normally 2-2.5V more that voltage rateing of battery,most eng mfg service manuals tell you if charge voltage in a regulated system over 15V DC to replace regulator/check alt stator.In an unregulated charging system the charging voltage can run 14-16v DC,this is after you subtract 1.1-1.5v drop thru inline diode from AC voltage of alt stator output & any possible current limit/voltage drop resistor after inline diode,this is why battery life is somewhat shorter with an unregulated system as battery is maintained at a full charge/slighty overcharged condition most of the time. [Reply]  [No Email]