These SLA =Sealed Lead Acid batteries usually have a charging rate for 2
types of usage The YUASA battery I have in front of me has the following
instructions (applicable at 20 degrees Celcius ) :
Standby Use : Voltage regulation 13.50 -13.80 V Initial current :
No Limit
Cyclic Use : voltage regulation 14.4 - 15.00 V Initial current:
1.75 Amperes max.

I also use a number of SLAs without such instructions , which I (safely)
charge at 0.1 C (for example a 7Ah battery is charged at 700 mA ) and
limiting the Voltage to 13.5 V ,bearing in mind that 12 V lead acid
batteries are still 70 -80 % charged when voltage has dropped to 12.6 V
To test (charged )12 V lead acid batteries I discharge them at a constant
0.1C current and check the time until the voltage has dropped to 11.9 V
(at that voltage the battery might not as yet be fully discharged ,but below
that voltage they are of no use to me )

Frank GM0CSZ / KN6WH

+++++++++++++++++++++++
So my question... If it measures 13.8-14v after charging, it should be
fully charged, right? Is there something going on since it is only drawing
10's of milliamps while charging? I've read that they charge at several
hundred milli's. I'd like to use my QRP rig remotely, and at the rate its
dropping, I just don't think it will serve the purpose.