My bike AGM - 12.1~12.2V. (65% SOC)
Charged within less than 10 minutes, 14.4V.
Switched off voltage - 12.8V.
Overnight voltage - 12.4~12.5V. (80% SOC)
QUOTE(dwRK @ Feb 3 2021, 06:10 PM)
my agm after 2-3 wks not used... 12.2v
car idling now charging at... 15.15v
after 1hr and engine stop... 15.15 -> 12.8v
my new spare mf last charged in December... 12.7v
my 3-months dead & revived 3+ years after 4hr rest... 12.7v
everything looking good
May I know what car? Do you modify anything to charge at 15.15V? It's measured at battery terminal?
QUOTE(dwRK @ Feb 3 2021, 06:25 PM)
can pump out 5A does not mean it must or will at all times...
usually it starts maxed out...then auto switch to trickle charging...
smart chargers will have proper v/a parameters for the fast & trickle phases
5A is not capable of doing fast charging. The CTEK he mentioned has AGM mode. He charged it once a month.
Just sharing what I understand, AGM charging mode requires constant voltage with max current clipped at 20% of C (20% of 100A = 20A). The CTEK from this standpoint is very safe, since it will never reach the max charging current, but the issue is charge time. It will take more than 4x time to complete the 'bulk' and 'absorption' stage. Another issue is, CTEK may have a safety cut-off, when the duration of charging is limited, and switched to the next charging phase. This safety causes the AGM to charge inappropriately.
Another problem with all-in-one chargers, is that it should require a bigger power supply to meet the max current. For example, the CTEK specifies 5A, so it should have a power supply capable of supplying more than 5A. Otherwise, the power supply itself will keep 'clipping'.
From what I read, if I want to charge my 65Ah MF, or a 65Ah AGM, I would need to buy a charger capable of 6.5A or 13A charging, respectively. Moreover, best practice for AGM is a following float charge for at least 6 hours before disconnecting the charger to complete the last 5% top off, once every 6 months.