55 Amp Converter Charge Times
It it possible for a 55 amp converter (with a 14.4 volt quick-charge mode) to take a new Interstate SRM-24 series Marine/RV battery that's discharged to 11.90 volts and charge it to 90% (12.58 volts) ...
Forum Discussion
Some converters are rated at their 13.6v level in their specs. This means they give the watts at 13.6 x 55 = 748w Now add on for the 0.7 PF and you draw 1068w (VA actually) Now throw in what might happen at 14.4v and 55a. Some converters (PD) can't do their 55a at the higher voltage stage because there isn't enough power because they are rated at 13.6.
In other words, it can get complicated. Yes you can get high amps at first at the 13.6v level, but it tapers very soon because the battery voltage rises into the low 13s and the converter is only at the mid 13s. Not enough "spread" (voltage diff) to make many amps.
The 14.4 level is used because now there is more "spread" between the battery voltage and the converter voltage, so you get more amps. (Until the "battery acceptance rate" gets to where it can't take that many amps anymore at that voltage, so amps taper (like under battery control for that due to its chemistry etc.)
Look again at my ugly graph above and the drooping curves to the right side. That is the amps tapering due to battery acceptance rate falling as SOC rises.
In other words, it can get complicated. Yes you can get high amps at first at the 13.6v level, but it tapers very soon because the battery voltage rises into the low 13s and the converter is only at the mid 13s. Not enough "spread" (voltage diff) to make many amps.
The 14.4 level is used because now there is more "spread" between the battery voltage and the converter voltage, so you get more amps. (Until the "battery acceptance rate" gets to where it can't take that many amps anymore at that voltage, so amps taper (like under battery control for that due to its chemistry etc.)
Look again at my ugly graph above and the drooping curves to the right side. That is the amps tapering due to battery acceptance rate falling as SOC rises.
