PD4655 Charging Graph
I have been reading quite a bit about different converters and charge rates, specifically some claims that PD's seem to drop off earlier than other brands. That is not what I have noticed on my setup,...
Forum Discussion
This is the other case where the PD did ok, but in this case with Wets. The change here was fatter wiring--much fatter! with 9ft of #2 (which is fairly fat IMO--should have been ok) his tapered.
Notice that his did taper slightly too from 61 to 57 instead of going straight across left to right with constant current case as you see with other chargers.
IMO this indicates there is still something not quite right with the PD, but that can be largely overcome with improving the wiring as these two cases show, whether Wets or AGMs. Probably means only get a PD if you can deck mount it close to the batts and not as a replacement lower portion with longer wire from the location.
I now see that the PD could be good for my set-up if I ever needed a replacement, since I could get the almost constant amps plus it has the CW. It stays at the high Vabs for the four hours, so no "gentle" stuff by dropping to 14.2 or 13.6 for the Absorption Stage.
ktmrfs Portland, Oregon
Posted: 02/16/13 08:14pm Link | Quote | Print | Notify Moderator
I have a PD60A unit that previously was connected to a pair of GC with about 9 ft of #2 wire. PD would start at 55A or so at 50%SOC and start tapering fairly quickly, within 15 minutes or so. It would be down to 45A pretty quick. Don't recall how long.
Now to my new setup
1) Battery bank consisting of 4 Trojan T-125's. 490AH
2) ALL interconnect with #3/0 welding cable with one minor exception. 12V side is 9ft #3/0, ground side is 6ft #3/0.
The exception is that the PD converter is connected to the #3/0 at my inverter input with about 9" of #4 cable for the ground and positive lead.
From there the #3/0 goes to a perko disconnect switch and directly to the battery. Battery is protected at the battery terminal with 150A MRBP fuse.
So to see how this performed, I discharged the battery bank to 50% per my trimetric, then started charging. Initial current was 61.5A, and now after 2 hours, it has tapered down to 59.4A. Trimetric says 72% SOC. I'll keep checking for the next two hours to see how the output voltage holds up. At 60A, the trimetric shows a 0.1V drop along the cable run.
so I guess the PD Can be a constant current source for a long while IF you have low enough resistance in the leads, and a big enough battery bank.
2 1/2 hours, down to 57.5A and up to 80%SOC
The data are:
inital current 61.5A
after 1 hour 60.5A
after 2 hours 59.4A
after 2.5 hours 57.5A output voltage now up to 14.0V so I suspect it will taper faster now.
after 3 hours, 43.4A, and output voltage is at 14.3V and 84% SOC
after 3.5hours, 32A and 90% SOC
So it basically held the 60A output for 2.5 hours before beginning to taper.
Notice that his did taper slightly too from 61 to 57 instead of going straight across left to right with constant current case as you see with other chargers.
IMO this indicates there is still something not quite right with the PD, but that can be largely overcome with improving the wiring as these two cases show, whether Wets or AGMs. Probably means only get a PD if you can deck mount it close to the batts and not as a replacement lower portion with longer wire from the location.
I now see that the PD could be good for my set-up if I ever needed a replacement, since I could get the almost constant amps plus it has the CW. It stays at the high Vabs for the four hours, so no "gentle" stuff by dropping to 14.2 or 13.6 for the Absorption Stage.
ktmrfs Portland, Oregon
Posted: 02/16/13 08:14pm Link | Quote | Print | Notify Moderator
I have a PD60A unit that previously was connected to a pair of GC with about 9 ft of #2 wire. PD would start at 55A or so at 50%SOC and start tapering fairly quickly, within 15 minutes or so. It would be down to 45A pretty quick. Don't recall how long.
Now to my new setup
1) Battery bank consisting of 4 Trojan T-125's. 490AH
2) ALL interconnect with #3/0 welding cable with one minor exception. 12V side is 9ft #3/0, ground side is 6ft #3/0.
The exception is that the PD converter is connected to the #3/0 at my inverter input with about 9" of #4 cable for the ground and positive lead.
From there the #3/0 goes to a perko disconnect switch and directly to the battery. Battery is protected at the battery terminal with 150A MRBP fuse.
So to see how this performed, I discharged the battery bank to 50% per my trimetric, then started charging. Initial current was 61.5A, and now after 2 hours, it has tapered down to 59.4A. Trimetric says 72% SOC. I'll keep checking for the next two hours to see how the output voltage holds up. At 60A, the trimetric shows a 0.1V drop along the cable run.
so I guess the PD Can be a constant current source for a long while IF you have low enough resistance in the leads, and a big enough battery bank.
2 1/2 hours, down to 57.5A and up to 80%SOC
The data are:
inital current 61.5A
after 1 hour 60.5A
after 2 hours 59.4A
after 2.5 hours 57.5A output voltage now up to 14.0V so I suspect it will taper faster now.
after 3 hours, 43.4A, and output voltage is at 14.3V and 84% SOC
after 3.5hours, 32A and 90% SOC
So it basically held the 60A output for 2.5 hours before beginning to taper.
