RV Power Converter Failure and Replacement

Our converter for the RV failed on our January 2014 Southern California trip so after the first couple of days the battery would not charge above 11.7 volts. On line there were lots of complaints about the Elexir Power Converter Charger model ELX-20 and I am unable to get the schematic. The converter is no longer made. After a physical inspection passed, no burnt resistors and such, I ordered a replacement converter that was rated high for $98 including shipping.

The new WFCO Ultra III Power Center model WF-8725P arrived in about a week. I was able to install this unit using the circuit breaker from the removed converter. The new Power Center can use a main breaker of 30 Amps however I have a 20 Amp in place. 20 Amps will likely be enough for our little Aliner trailer. This circuit just powers the 12 volt converter portion of the Power Center which can output 25 Amps 12 Vdc power. The unit uses two more 15 amp circuit breakers for 120 vac circuits in the trailer which power outlets, microwave, refrigerator at times and the air conditioner. There is also four 12 vdc circuits for refrigerator at times, furnace, radio, carbon monoxide detector, lights and water pump. The new unit uses aluminum wire which is hard for me to accept since the trailer uses copper wire. The crossover point is the weak link as I understand.

From Power Center 12 Vdc circuits -
     Green - water pump and furnace  (In USA Green is safety ground)
     Yellow - inside lights and radio
     Blue -
     Red - RV battery charge

The Operation modes of the Power Center are -
     Bulk mode: Puts out 14. 4 Vdc for maximum of 4 hours.
     Absorption mode: 13.6Vdc which is the normal mode.
     Float mode: 13.2 Vdc for a trickle charge of the battery.

I still may be able to repair the old converter I suppose, but without a schematic it might be a challenge and I see some of the parts do not have legible part numbers. Might just toss the bad one.

After two days of 120 Vac being off the RV battery reads 12.7 Vdc which is so much better than the 11.7 Vdc we had before.

Per several charts off the internet -
Volts --- Remaining Capacity
12.63 --- 100%
12.54 --- 90%
12.45 --- 80%   (75%)
12.36 --- 70%
12.27 --- 60%
12.18 --- 50%   (12.24 --- 50%)
12.09 --- 40%
12.00 --- 30%   (12.06 --- 25%)
11.91 --- 20%
11.82 --- 10%   (11.89 --- 0%)
11.80 --- 0%