First, thanks to everyone for the excellent help in my previous thread about battery types.
Now, here's what I've got:
'07 Interstate with Varta flooded group 27 100Ah that didn't see a lot of shoreline charge time for the first 2 years (my own fault, lesson learned) getting the occasional charge by running the generator or the engine alternator. 7355 parallax converter, no timer option that I know of. (panel says "option B", not sure what that is... spec sheet says option T is the float charge timer). I have used a 400W inverter (and hope to do so again in the future) for running a 15" LCD without running the generator, but stopped when my uinverter started regularly giving me low-voltage warnings.
Here are the symptoms:
- Battery voltage (measured on the terminals, disconnected via solenoid) was steady at ~8V even after several nights plugged in to a 15A circuit via shoreline.
- I recently topped off the battery water level, and it was never below the plates.
- Converter output voltage (measured from the panel front when connected to a shore line with just cabin lights turned on) is around 13V, not 13.5-14 as expected for charging.
- After a weekend connected to a shoreline, folllowed by a few more hours at home connected to AC I got the disconnected battery to measure 10.5V, but could watch it drop by 10 mV per second or two, presumably headed back to the 8V I measured previously.
- All systems/appliances work fine when connected to shoreline, 12V
systems work fine off the engine alternator when the engine is running, but 12V
systems suffer under the low battery voltage when the engine is off and shoreline not connected.
Here's what I'm trying to figure out:
- Is the battery salvagable, or is it trashed already? My prior lack of understanding of proper charging has lead to this for sure, but is it too late to save it?
- Is the converter outputting a proper voltage for charging?
- Since the battery is (very inconveniently) mounted under the passenger's seat, and an AGM would eliminate PITA electrolyte level checks that can require removal of the seat, does the 7355 converter without the timer option provide the appropriate output for the AGM type batteries?
Thanks in advance, this forum is nothing short of amazing!