I discovered that my AC to DC converter was not putting out any DC current. Gound that the fuses were blown and replaced them. Now I get 13.96 VDC with nothing connected. When I connect it to the coach leads, voltage drops to 1.6 VDC. The batteries were down to just over 11.0 VDC and I put a 6 amp charger on them and they are not at 11.6 VDC. There is only one thing running that would be using DC current and that is the refrigerator running on 120 VAC but uses the 12 VDC for the control circuit board. When the cables are connected and converter turned on there is no increase in voltage at the coach batteries. They still read 11.6 VDC. Any suggestions at what to check?
Vehicle Parts & Accessories - Camper - Rv Motorhome Dual Co & Lp Gas Alarm Detector
Answers & Comments
If the battery will not charge above 11.6 volts with your 6 amp charger after 24 hours, indicates that one cell has shorted or partially shorted. There is no cure for this other than replacement unfortunately. Your convertor trying to charge the battery would not be current limited like the 6 amp charger and hence would blow the fuse.
Each cell of a lead acid battery is 2.2 volts. 13.96 is the correct voltage for your coach charger. Connect an automobile head lamp bulb to your coach charger and see if it will maintain around the 13.9 volts under load. If it won't, then the coach charger has been damaged.
If you have a charging diode from the vehicle alternator for dual charge, that device may have failed allowing the load of the starter motor to be drawn from the auxilary battery and the voltage spike from the starter motor MAY have wiped out your coach charger IF it is electronically regulated.
In summation: Check that your battery will charge up to at least 12.5 volts with no load using your 6 amp charger. Check that your coach charger will light a head lamp when not connected to the battery.
If you have a charging splitter from your vehicle alternator, check both diodes in that unit are healthy.
I appreciate your offer but I have already solved the problem. The converter is still good. All it needed was the two 30 amp polarity fuses replaced.
The problem was in the wiring. The positive cable from the converter to the batteries would not conduct current. I replaced this cable and everything is working as it is suppposed to.
Great... However, PLEASE check for bad insulation or other possible shorts as an open wire to the convertor would NOT cause the fuses to blow! MOST wires that "won't conduct" are really problems at the terminals. For safety do check where the short occured UNLESS you know that a mistake was made by "jumping" the battery in reverse which would have blown the fuses. If this mistake happened, that could have blown the fuses AND destroyed the positive cable. Please note that some of these cables have fusible links in them as a last ditch fuse should a short occur to prevent the attached battery from literally exploding. Usually you can detect the cables that have a fusible link in them by a bulge along the length somewhere. These are VERY common in automobiles. If your cable had such a link MAKE SURE you replace it with an identical one for your own safety... A fire within an RV is very dangerous.