upgrading power converter
My power converter has apparently bit the dust, lights flickering for past couple of years now no charge to batteries... Anyhoo, we do a lot of dry camping, where we need to daily boost the batteries...
Forum Discussion
ah64id wrote:
I am not sure how you can hold more amps and maintain the set voltage. I am sure there are graphs, but it doesn't make sense.
If the PD is holding the 14.4V the it's pushing the proper amps, whether that is 55 or 1.
We seem to be talking about different things here. Been several many threads about all this over the years and lots of graphs shown.
The idea is to have a charging profile that looks like these (scroll way down) two at the bottom where the rated amps go straight across left to right until voltage reaches "threshold", then amps taper while voltage is held at whatever Vabs is in that charger.
Unfortunately, the PD's graph during bulk stage looks more like the first graph's amps shown here where the amps taper from the start.
http://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdf
I don't have a plot for the new PowerMax PM4s. AFAIK they are similar to the PM3, but have a new feature that they go into bulk right away no matter what battery SOC is (no need to be down to 50% SOC anymore), then after 15 minutes they decide if the battery is already high enough it can go to Float or keep at Bulk for a while longer.
My older PowerMax PM3 did bulk ok at rated amps, but then dropped to 13.6 for its programmed Vabs. They went the "gentle" route.
I didn't like that at all, so I jacked up the voltage with its internal pot to 14.8. Now it does bulk the same, but then stays at 14.8 forever. That means I have to turn it off when the batteries are all done and then use a different charger for Float. (I use the trailer's original 7355 converter when on shore power)
