locked Re: Batteries starting to get weak - MMM - What to do -
Scott SV Tengah
Great that you took the plunge. Those Agm batteries aren't cheap so if you can keep your lithium alive, I'm certain it will save you money over the long term.
I'm a little confused on your air con runtime on battery. Not sure about the sm, but on our 54 we have a Climma 9 in the aft cabin, which draws 782watts/26.3v=29.7amps and the calpeda pump draws 14 amps. FYI the voltage is what my victron has calculated as the average voltage under draw during the last two years. The climma draw is per spec, but only when the compressor is running. So even assuming the extreme/unrealistic case of 100% duty cycle, that's 44 amps an hour or around 132 amp hours over 3 hours. With your 600amps at 24v, you should be able to run much longer than 3 hours. Perhaps your battery monitor is not calibrated correctly? Or perhaps you're talking about running all 3 air con units?
I'm always excited by a cheaper way to do the same thing. The victron / master volt setup is far more expensive but I guess two years ago when I installed it, I was so inexperienced with this lithium stuff and given the catastrophic battery failure and boat damage that can occur if you don't have the proper safety measures in place, I was too chicken to try it on my own.
Excited to see how you managed those risks for far less cost than we (Garulfo, Joerg, myself) did. Too late for me but perhaps it can help others.
2007 A54 #69