cruiseoncraig
Member
- Joined
- Jul 30, 2015
- Messages
- 12
- Fluid Motion Model
- C-28
- Non-Fluid Motion Model
- Cutwater 28
- Vessel Name
- Cruise On
- MMSI Number
- 367495180
This was our second year of cruising with our Cutwater 28 and I finally found the formula for living on the batteries. First of all a Xantrex Link Pro or other battery monitoring device is essential. The Link measures every amp of power consumed and every amp of power generated by the alternator, solar panels, or shore power battery charger and tells you how full the batteries are. It's like a fuel gauge for your batteries. It also does some other cool things like telling you how much amperage a particular device on your boat is consuming, but most importantly for us is the reserve percent.
The Volvo D4 we have has a 120 amp alternator....that is huge. We also have two solar panels and they help, but are not necessary in my opinion. This year we also packed a Honda 2000 watt generator along thinking it would be a big help. The DC charger built into the generator is almost useless, like 4 amps, so we are left to plug in the shorepower cord and run the onboard charger. The onboard charger is 40 amps meaning you are getting about 20 amps of continuous charge. That's okay when you are plugged in at the marina overnight, but it is not a good bang for the noise buck when trying to charge the batteries with a generator. The only time it made sense to use it was while trailering down the highway. You can't hear it then and I don't know of a way to charge the boat batteries with the pickup alternator.
So here is the bottom line. We keep the batteries between 53 and 78 percent by running the engine for one hour at 1140 rpm. 53% is arbitrary, I just know from reading that anything less than 50% deteriorates the batteries rapidly. After 78% (we have AGMS by the way) you can run it another hour and only achieve 83% of reserve because the regulator shifts the alternator to float charge and you get very little bang for the buck. So at 53% we run one hour and achieve 78% and call it good. I also know it is important to charge the batteries to 100% from time to time, but I believe even once per month is enough with AGM's. They don't have as much of a sulfonation problem that lead acid have. We found that motoring to a new anchorage for about five hours, coupled with the solar panels I assume, we get 100% charge on the batteries.
We have had a lot of boats and even lived full time on a sailing cat for a few years. Never have I been more happy and confident in my batteries than by using this method. In the late evening we check the Link and if we have over 60% reserve we know we will make it until morning. When we wake up in the morning the first thing we do is check the Link and when it gets close to 53% we run the engine for one hour unless we know we are moving the boat soon. I think there is even an alarm on the Link that you can set to go off at whatever percent you choose. We haven't done that yet because we get a weird kick out of babysitting the Link. Try it you'll like it.
The Axioms of Boating: Keep the boat in the water, keep the water out of the boat and keep the people in the boat.
The Volvo D4 we have has a 120 amp alternator....that is huge. We also have two solar panels and they help, but are not necessary in my opinion. This year we also packed a Honda 2000 watt generator along thinking it would be a big help. The DC charger built into the generator is almost useless, like 4 amps, so we are left to plug in the shorepower cord and run the onboard charger. The onboard charger is 40 amps meaning you are getting about 20 amps of continuous charge. That's okay when you are plugged in at the marina overnight, but it is not a good bang for the noise buck when trying to charge the batteries with a generator. The only time it made sense to use it was while trailering down the highway. You can't hear it then and I don't know of a way to charge the boat batteries with the pickup alternator.
So here is the bottom line. We keep the batteries between 53 and 78 percent by running the engine for one hour at 1140 rpm. 53% is arbitrary, I just know from reading that anything less than 50% deteriorates the batteries rapidly. After 78% (we have AGMS by the way) you can run it another hour and only achieve 83% of reserve because the regulator shifts the alternator to float charge and you get very little bang for the buck. So at 53% we run one hour and achieve 78% and call it good. I also know it is important to charge the batteries to 100% from time to time, but I believe even once per month is enough with AGM's. They don't have as much of a sulfonation problem that lead acid have. We found that motoring to a new anchorage for about five hours, coupled with the solar panels I assume, we get 100% charge on the batteries.
We have had a lot of boats and even lived full time on a sailing cat for a few years. Never have I been more happy and confident in my batteries than by using this method. In the late evening we check the Link and if we have over 60% reserve we know we will make it until morning. When we wake up in the morning the first thing we do is check the Link and when it gets close to 53% we run the engine for one hour unless we know we are moving the boat soon. I think there is even an alarm on the Link that you can set to go off at whatever percent you choose. We haven't done that yet because we get a weird kick out of babysitting the Link. Try it you'll like it.
The Axioms of Boating: Keep the boat in the water, keep the water out of the boat and keep the people in the boat.