My last boat was very minimalist, with only a 27ah house battery and only lighting loads, and most of the places we went we had access to shore power if needed, so I don't have a lot of experience with power management.
Our new boat has significantly more than that! We have a 550ah bank of flooded cell batteries providing power for a Webasto heater, refrigeration, electronics, auto helm, audio system, and even a 200w inverter powering a 22" led TV, (although I doubt I will use the TV much).
This weekend was our first time taking the boat "off grid", so I was watching battery voltages carefully to get some idea how long we could go without recharging. Unfortunately the boat is not yet equipped with an ammeter, so I don't know how much we were drawing. We started with fully charged batteries at 12.8v. Our main loads were the refrigeration and the heater. I have already upgraded all lighting to led so that is a negligible load. After 24hrs I saw the voltage dropping as low as 12.3v, but that was when both the heater and the fridge were running. When both units cycled off, voltage recovered to 12.5v
So when judging how discharged the bank is, should I be referencing the voltage under load, or at rest? My understanding is that you don't want to discharge more than 50% or about 12.2v. It seems to me my batteries were already getting low. I would have expected to be able to go longer than 24hrs without charging with my relatively large bank.
What should I expect from my batteries?
Sent from my SM-G960W using Tapatalk
Our new boat has significantly more than that! We have a 550ah bank of flooded cell batteries providing power for a Webasto heater, refrigeration, electronics, auto helm, audio system, and even a 200w inverter powering a 22" led TV, (although I doubt I will use the TV much).
This weekend was our first time taking the boat "off grid", so I was watching battery voltages carefully to get some idea how long we could go without recharging. Unfortunately the boat is not yet equipped with an ammeter, so I don't know how much we were drawing. We started with fully charged batteries at 12.8v. Our main loads were the refrigeration and the heater. I have already upgraded all lighting to led so that is a negligible load. After 24hrs I saw the voltage dropping as low as 12.3v, but that was when both the heater and the fridge were running. When both units cycled off, voltage recovered to 12.5v
So when judging how discharged the bank is, should I be referencing the voltage under load, or at rest? My understanding is that you don't want to discharge more than 50% or about 12.2v. It seems to me my batteries were already getting low. I would have expected to be able to go longer than 24hrs without charging with my relatively large bank.
What should I expect from my batteries?
Sent from my SM-G960W using Tapatalk