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
BF,
Note I didn't mention a 20hr rate in my post. I said draw 20 amps out for 5 hours so 100 AH would be missing from the 200 AH battery bank. The last time I checked, 100 AH taken out of a 200 AH battery bank should leave it at 50% SOC. This in turn should leave "good batteries" at a terminal rest voltage of around 12.1 volts, give or take. This would be a good test - if my batteries' terminal voltage was way less than around 12.1 volts after 1/2 of their when-new energy was removed - then I figure they're getting near the end of their life. I should make this test one of these days ... perhaps only after drinking some strong java so I don't mess the test up.
BTW, whenever I think my batteries are full, it's based on them accepting no more current ... nada ... they just sit there drawing no charging current. They're up against what I call a "hard stop". If I hit them with 14.XX volts (from the Ford alternator - after many hours on the converter) to try and get them take some more current at the higher voltage, they won't ... still no current. I don't think wet cell batteries act this way. It's been my experience that wet cells will sit there always soaking up "some" current with some charging voltage placed on their terminals after their hydrometer readings show fully charged, since they have a liquid in them that is always conductive to electron flow.
We need a system in RVs that tells us definitively when AGM batteries need replacing so that AGM batteries don't keep us from sleeping at night. To bad we can't drill a hole in them and poke in a hydrometer.
Note I didn't mention a 20hr rate in my post. I said draw 20 amps out for 5 hours so 100 AH would be missing from the 200 AH battery bank. The last time I checked, 100 AH taken out of a 200 AH battery bank should leave it at 50% SOC. This in turn should leave "good batteries" at a terminal rest voltage of around 12.1 volts, give or take. This would be a good test - if my batteries' terminal voltage was way less than around 12.1 volts after 1/2 of their when-new energy was removed - then I figure they're getting near the end of their life. I should make this test one of these days ... perhaps only after drinking some strong java so I don't mess the test up.
BTW, whenever I think my batteries are full, it's based on them accepting no more current ... nada ... they just sit there drawing no charging current. They're up against what I call a "hard stop". If I hit them with 14.XX volts (from the Ford alternator - after many hours on the converter) to try and get them take some more current at the higher voltage, they won't ... still no current. I don't think wet cell batteries act this way. It's been my experience that wet cells will sit there always soaking up "some" current with some charging voltage placed on their terminals after their hydrometer readings show fully charged, since they have a liquid in them that is always conductive to electron flow.
We need a system in RVs that tells us definitively when AGM batteries need replacing so that AGM batteries don't keep us from sleeping at night. To bad we can't drill a hole in them and poke in a hydrometer.
