My solar and the chassis batteries
Outside of Quartzsite boondocking for the last month. Very happy with the solar but have one last question i thought id throw out to the group. I can hear that Aux Start relay kicking in. Im thinki...
Forum Discussion
I'm on my 2nd Trombetta - the first one went about 7-8 years.
However, what my non-Trombetta original stock automotive-type solenoid (lastest about 2 years) and the 1st Trombetta did was to still latch IN and OUT OK when hit with 12 volts on their coils ... but NOT make a dead short connection between it's input terminal and output terminal like they were supposed to when the contacts were closed.
I'm guessing that their contacts gradually became corroded/eroded enough over time such that they went just a bit too resistive. Thus when charging low coach batteries via the engine alternator - due to heavy current flow - the voltage on the solenoids' output side was lower than the voltage on the solenoids' input side. I saw this happen as it occured with both solenoids because I have a four-place voltmeter constantly monitoring each side of the solenoid whenever the engine is running (the voltmeters are mounted on the cab dash) and charging low coach batteries. The alternator side of the solenoid might read, say, 14.3 volts but the coach battery side of the solenoid might read only 12.8 volts .... thus the coach batteries would not be getting charged anywhere near as fast as they should have. This voltage drop across the solenoids' contacts could only have been caused by the contacts going resistive.
The reason I switched to the first Trombetta solenoid after the OEM solenoid failure was the silver coated contacts on the Trombetta. The silver coating slows up corrosion/erosion of the contacts when carrying heavy currents over time, thus explaining the 2 years contact life of the OEM solenoid versus the 7-8 years contact life of the 1st Trombetta. I'm hoping to get at least another 7-8 years out of the 2nd Trombetta with it's silver coated contacts.
I wonder how many motorhome RVer's out there arrive at campsites with low coach batteries ... and either don't realize it or don't understand why ... merely because their alternator-to-coach-battery interconnect solenoid is "latchinig" but not permitting full available current flow to the coach batteries due to voltage drop across high resistance solenoid contacts?
However, what my non-Trombetta original stock automotive-type solenoid (lastest about 2 years) and the 1st Trombetta did was to still latch IN and OUT OK when hit with 12 volts on their coils ... but NOT make a dead short connection between it's input terminal and output terminal like they were supposed to when the contacts were closed.
I'm guessing that their contacts gradually became corroded/eroded enough over time such that they went just a bit too resistive. Thus when charging low coach batteries via the engine alternator - due to heavy current flow - the voltage on the solenoids' output side was lower than the voltage on the solenoids' input side. I saw this happen as it occured with both solenoids because I have a four-place voltmeter constantly monitoring each side of the solenoid whenever the engine is running (the voltmeters are mounted on the cab dash) and charging low coach batteries. The alternator side of the solenoid might read, say, 14.3 volts but the coach battery side of the solenoid might read only 12.8 volts .... thus the coach batteries would not be getting charged anywhere near as fast as they should have. This voltage drop across the solenoids' contacts could only have been caused by the contacts going resistive.
The reason I switched to the first Trombetta solenoid after the OEM solenoid failure was the silver coated contacts on the Trombetta. The silver coating slows up corrosion/erosion of the contacts when carrying heavy currents over time, thus explaining the 2 years contact life of the OEM solenoid versus the 7-8 years contact life of the 1st Trombetta. I'm hoping to get at least another 7-8 years out of the 2nd Trombetta with it's silver coated contacts.
I wonder how many motorhome RVer's out there arrive at campsites with low coach batteries ... and either don't realize it or don't understand why ... merely because their alternator-to-coach-battery interconnect solenoid is "latchinig" but not permitting full available current flow to the coach batteries due to voltage drop across high resistance solenoid contacts?
