Thank you Charles. I agree with most of your analysis.
"This Blue Sea information and chart is very useful.
https://www.bluesea.com/resources/1437"
The chart is for
"Critical circuits, with 3% allowable voltage drop, include
Panel main feeders
Bilge blowers
Electronics
Navigation lights
Non-critical circuits, with 10% allowable voltage drop, include
General lighting
Windlasses
Bait pumps
General appliances"
It is not for home 120 volt AC wiring (1.5% voltage drop) or for lead acid battery charging. 14.4 fast charge voltage - 11.5 discharged battery voltage = 3 volts pushing current through the battery.
You would need remote voltage sensing for the battery charger to use such small wire. I have a 20 amp remote sensing marine battery charger. It works with smaller wire. I don't use it in my RV.
RV chargers usually sense voltage inside themselves and assume little or no voltage drop so short large capacity wires are required.
"My trailer had a WFCO multistage converter (WF-9845) installed in the place of the Parallax converter when I bought it, but after experimenting with it, I found it acted just as I had read that they do, and would not drop to the 13.2 volts and sometimes even stuck on the bulk charge mode long after it should have dropped."
Parallax converters are excellent converter/chargers. Some even come with an inverter and a transfer switch built in. An excellent choice.
I have a WFCO. It does work as advertised. WFCO makes a line of converter/chargers that all use the same microprocessor control program.
You must fully understand the logic to be able to interpret the results. "Bulk", "Absorption" and similar words are imprecise and sometimes redefined by various people, so I use actual terminal voltage.
WFCO has posted a very good description of how the microprocessor works. Check their web site. I tested mine. It does what WFCO says it does. However, imprecise testing can lead to false conclusions.
The WFCO will drop to 13.2 volts when output conditions are met. Current must be low for 4 days (poor memory?). Current must be constant. Turning on a light will cause it to jump up to 13.6 volts. An automatic "on" light when you open the battery bay door will cause the jump. An automatic device like a water heater control that uses 12 volts will turn "on" periodically and cause a current change. That will cause it to jump to 13.6 volts.
In any case 13.6 is a safe voltage for most AGM and flooded cell lead acid batteries. 13.2 is optimum for storage.
The WFCO will rise to 14.4 volts provided output meets processor criteria. Current must be high, but not above charger maximum capability. It will only continue at 14.4 volts for 4 hours.
If high current does not drop below maximum charger capability, it will not reach 14.4 volts in 4 hours and will stabilize at 13.6.
Mine does this because I am using a 30 amp WFCO intended for a 70 amp hour battery to charge a 200 amp hour battery bank. I would need a 50 or 60 amp capacity WFCO to get it to raise to 14.4 volts in the first 4 hours.
"The PD 9245-CV is the retail version of the 45 amp with the remote charge wizard pendant included. The charge wizard pendant allows you to force it into bulk charge mode when it doesn't normally want to, allowing charging in a shorter period of time while running on a generator."
Actually, forcing the charger to "bulk" mode will not charge lead acid batteries faster. It will increase the current into the batteries. But, lead acid batteries have a limited ability to absorb the current being forced into them.
Excess energy is used to turn water into hydrogen and oxygen gas. Some of it used to cause "grid corrosion". That is why the best chargers normally drop to 13.6 volts after an initial 14.4 volt "fast" charge phase.
I wish you good luck and happy trails ahead!
Linear Mode
