parallax power supply 7345ru parts PWM
My 7345 is not charging the coach batteries but does supply 12power to all accessories. The transformer, fan and relays work fine. Think i need a PWM circuit for it. Contacted PP tec support and th...
Forum Discussion
My Itasca (Winnebago) Class C motorhome came stock with a Parallax 7345 converter. A few months after owning the RV the 7345 began to fail by running only some of the 12V items in the RV and not charging the batteries. I found out by trial and error that the 7345 would only provide up to around 8 amps before it's voltage would begin dropping off real fast - hence it's failure to charge the batteries, while seeming to still power most other 12V items in the RV.
The fix for us was another new 7345 provided under warranty which still runs fine after 6-7 years.
Our 7345, combined with our battery types (AGM) and camping style (only a few days at a campsite before traveling) and along with the main engine alternator, does just fine taking care of our RV batteries. Winnebago installed 8 gage wiring between the batteries and the 7345. I checked the 7345's terminal capacity and determined that they could fit up to about 2 gage wiring ... so I should have upgraded the wiring but never did.
For regular wet cell RV batteries, probably a charger that starts out with voltages above 14 volts would be better than the 7345's fixed ~13.8 volts. The 7345 circuit schematic shown earlier in this discussion thread (provided by Salvo some time ago) "moves" the 7345's voltage sensing point from right at the 7345's terminals out to the RV battery bank's terminals to eliminate voltage drop in the cabling regardless of current flow ... plus, I think, raises up a bit the 7345's 13.8 fixed voltage set point. If so on raising the fixed voltage value, I'm not sure how Salvo's circuit would be as a longer-term bulk or float charger though ... maybe even harder on wet cell batteries than a stock 7345 with it's fixed 13.8 volt output.
For our AGM RV battery situation the batteries say right on their label to float them with 13.5 volts to 13.8 volts, so the 7345 is excellent for floating them. Since AGM batteries accept more charge current at any voltage you apply to their terminals, for our camping style the 7345 also charges the RV batteries quick enough. Hence in our situation the 7345 both charges and floats the RV batteries ... so far after over 7 years on the same set of AGM batteries. I made the choice years ago to put money into the better battery technology instead of replacing a perfectly good 7345 converter.
The fix for us was another new 7345 provided under warranty which still runs fine after 6-7 years.
Our 7345, combined with our battery types (AGM) and camping style (only a few days at a campsite before traveling) and along with the main engine alternator, does just fine taking care of our RV batteries. Winnebago installed 8 gage wiring between the batteries and the 7345. I checked the 7345's terminal capacity and determined that they could fit up to about 2 gage wiring ... so I should have upgraded the wiring but never did.
For regular wet cell RV batteries, probably a charger that starts out with voltages above 14 volts would be better than the 7345's fixed ~13.8 volts. The 7345 circuit schematic shown earlier in this discussion thread (provided by Salvo some time ago) "moves" the 7345's voltage sensing point from right at the 7345's terminals out to the RV battery bank's terminals to eliminate voltage drop in the cabling regardless of current flow ... plus, I think, raises up a bit the 7345's 13.8 fixed voltage set point. If so on raising the fixed voltage value, I'm not sure how Salvo's circuit would be as a longer-term bulk or float charger though ... maybe even harder on wet cell batteries than a stock 7345 with it's fixed 13.8 volt output.
For our AGM RV battery situation the batteries say right on their label to float them with 13.5 volts to 13.8 volts, so the 7345 is excellent for floating them. Since AGM batteries accept more charge current at any voltage you apply to their terminals, for our camping style the 7345 also charges the RV batteries quick enough. Hence in our situation the 7345 both charges and floats the RV batteries ... so far after over 7 years on the same set of AGM batteries. I made the choice years ago to put money into the better battery technology instead of replacing a perfectly good 7345 converter.
