Hmmmm not charging it would seem

[Anonymous]

Hi first of the bike is a 79 GS850G, Brand new battery prepaird just like the directions said to, 13.4V @2500rpm I rode the bike for about 15 miles today with no lights or anything. It sat for several hours "about 5 hours" When I got back it turned over one time and thats all the juce she had. This is an ongoing problem. The battery stays charged enough to kick start it every time but I never get to use my starter as there is never enough power. Recently I rode for 45 minutes strait. Shut the bike off, opend the garage dore and bam she was dead that fast. Any help is apreciated

[Redman]

So you get a new battery and still having problems. THats annoying.

When you say brand new battery "prepaired like it said". Referening to filling it with the I assume. Are you also refering to putting it on a charger (3/4th or 1 amp) for several hours?

You say 13.4 volts at 2500 rpm. That more volts than before you started the bike? Volts any higher at higher rpm? like at 4-5 thous rpm maybe 14-14.5 volts?

[Anonymous]

Darn To late to start the bike and bring it up to 4-5k "My boy is sleeping". I will try to remember to do this tomorow morning and post all the answers to your questions then

[nabrams]

Brand new, fully charged battery and it drains after less than an hour - sounds like your regulator/rectifier and/or stator are faulty.
You'll want to do the tests listed in the "stator papers" (in the garage section of this site).
So far, I've had three bikes from that era (all 1980 or 1981) that had bad regulator/rectifiers. Two of them were overcharging (17-18 volts at 5000 RPM) and therefore boiling the battery dry. The third was not charging at all (my voltage actually decreased at higher RPM).
Over the last several years, I've been buying non-running bikes, get them running and then sell them (usually I just break even, but it's a fun hobby). Every one of them had some sort of charging problem.