View Single Post

03-17-2017, 08:35 PM
 Aaron Co-Founder & Moderator Join Date: Feb 2007 Location: Washington State Posts: 10,946
resting voltage

Quote:
 Originally Posted by bryanx78 hi! I try to recharge a lead battery (12v - 5ah) with my ssg model. Voltage increase speedly, but when i turn off my circuit (when battery voltage arrive to about 15v!), voltage battery drop to about 12,4v!!! Is normal? How much i must go up? Thanks!
It is normal for battery voltage to drop and settle like that after charging - that will happen even with conventional chargers. If you have a resting voltage of 12.4 volts, it's in fairly good shape. At 5ah, is that a gel cell? If so, 14.8 is about as high as you want to push it.

If you want a higher resting voltage, if the battery can be brought back more, discharge with a 20 hour rate = 5ah / 20 hours = 0.25 amps x 12v = 3 watts. If you put on a 3 watt load on that battery after fully charged, let it bring the battery down to 12v then recharge it fully again and repeat a few times. Each time, that battery should have a bit higher resting voltage each time.
__________________
Sincerely,
Aaron Murakami