What began as a reconnaissance mission to trace some wires to learn how my boat ticks and make sure I wasn’t sitting on a electrical fire waiting to happen has turned into the addition of a dedicated house battery, and an eventual all-out revamping of the entire 12v system on June Bug.
Whoever set up the electrical system and battery bank before I bought the boat did a decent job of joining two 58Ah lead acid “hybrid” starter/deep cell batteries from Costco in parallel, charged by a 3-stage Guest brand battery charger. There is a 100w solar panel mounted on the back of the boat that I haven’t really used yet, but it produces a fair amount of power when plugged in.
I mostly stay at the dock plugged into shore power and have yet to do a weekend excursion to Catalina, but this system has worked well and the batteries always have plenty of juice to fire up my Kubota diesel. However, I have always been skeptical about whether or not these batteries would hold up after a weekend unplugged from the dock.
I’ve watched many of Jeff Cote’s videos from Pacific Yacht Systems, looked at fellow EY.O’s Christian Williams’ posts on his electrical upgrades, watched the Dakota Lithium guy’s videos, and spoken to several boating friends about batteries. After consulting someone a lot smarter than me, I decided to keep my current battery setup intact as a starter battery bank, and go with an all-Victron LiFePO4 (Lithium Iron Phosphate) battery system to use as my house battery. It’s a small boat and we don’t have much to power except for a electric cooler, so one 100ah battery should be sufficient - for now.
I purchased everything from Northern Arizona Wind and Solar out of Flagstaff. It’s not cheap, but I follow the general rule of thumb of, “Will I be comfortable if my 82 year old mother in law comes onto this boat?” This keeps me from indulging my inner MacGyver too much, or doing anything too experimental, especially when electricity comes into play.
Victron has come out with a new BMS (battery management system) for 12v systems charged by an alternator - the Smart BMS CL 12/100. It looks like it was originally designed for camper vans, but it works really well for boats too. It works as a system, so you also have to use a Victron LiFePO4 battery and a Victron SBP (Smart BatteryProtect), which prevents the loads from draining your battery too low.
Basically, the BMS CL 12/100 works as a conduit through which you can charge your LiFePO4 battery from your alternator or starter battery. Whenever the voltage from your alternator, or any other connected source (charger, solar) goes above 13.1v, the BMS allows the current to flow to the LiFePO4 battery. It is limited by a fuse, depending on how many amps your alternator puts out, so that you don’t fry your alternator while charging, and the current is only allowed to flow in one direction, so it won’t flow backwards from the battery back to the alternator to damage it that way either.
To complete the indoctrination to all things Victron, I’ve added a BMV-712 Battery Monitor to my DC panel so I’ll know what’s going on with loads coming in and leaving my boat. You can add an additional charger to the system, but I don’t think I’ll have to. Time will tell, but so far it seems to be working well.
I’ve also added a Victron Galvanic Isolator because when I was following the wires around my boat I realized that the ground wire from the AC side which was attached to the fuel tank lead to nowhere. Upon further consultation with my Nigel Calder book, I learned that it needed to be connected to the boat’s ground and that I needed to put a galvanic isolator between the AC ground and DC ground.
Here’s everything tucked inside an old battery box I picked up at Minney’s in Newport Beach. Starting from the battery and going clockwise: Victron Smart LiFePO4 100 Ah battery, 100amp fuse, Smart Battery Protect 12/24 220, Smart BMS CL 12-100, Shunt for BMV-712, DC negative distribution bus bar.
Here’s a better look at the Smart BatteryProtect 12/24 220 (inside the box), the Smart BMS CL 12-100, the shunt and the negative distribution bus.
Here’s an old dagger board that I found stuck in a crevice of the boat which I have used as a mounting board for my galvanic isolator, DC positive distribution bus bars, and fuses.
DC positive switched and un-switched distribution bus bars, fuses, and Galvanic Isolator mounted alongside the starter batteries.
Another view of everything mounted.
My version of a schematic. Many apologies to any real electricians out there. This is the way it makes sense to me.
Again, my sketch of all of the components without wires.
Whoever set up the electrical system and battery bank before I bought the boat did a decent job of joining two 58Ah lead acid “hybrid” starter/deep cell batteries from Costco in parallel, charged by a 3-stage Guest brand battery charger. There is a 100w solar panel mounted on the back of the boat that I haven’t really used yet, but it produces a fair amount of power when plugged in.
I mostly stay at the dock plugged into shore power and have yet to do a weekend excursion to Catalina, but this system has worked well and the batteries always have plenty of juice to fire up my Kubota diesel. However, I have always been skeptical about whether or not these batteries would hold up after a weekend unplugged from the dock.
I’ve watched many of Jeff Cote’s videos from Pacific Yacht Systems, looked at fellow EY.O’s Christian Williams’ posts on his electrical upgrades, watched the Dakota Lithium guy’s videos, and spoken to several boating friends about batteries. After consulting someone a lot smarter than me, I decided to keep my current battery setup intact as a starter battery bank, and go with an all-Victron LiFePO4 (Lithium Iron Phosphate) battery system to use as my house battery. It’s a small boat and we don’t have much to power except for a electric cooler, so one 100ah battery should be sufficient - for now.
I purchased everything from Northern Arizona Wind and Solar out of Flagstaff. It’s not cheap, but I follow the general rule of thumb of, “Will I be comfortable if my 82 year old mother in law comes onto this boat?” This keeps me from indulging my inner MacGyver too much, or doing anything too experimental, especially when electricity comes into play.
Victron has come out with a new BMS (battery management system) for 12v systems charged by an alternator - the Smart BMS CL 12/100. It looks like it was originally designed for camper vans, but it works really well for boats too. It works as a system, so you also have to use a Victron LiFePO4 battery and a Victron SBP (Smart BatteryProtect), which prevents the loads from draining your battery too low.
Basically, the BMS CL 12/100 works as a conduit through which you can charge your LiFePO4 battery from your alternator or starter battery. Whenever the voltage from your alternator, or any other connected source (charger, solar) goes above 13.1v, the BMS allows the current to flow to the LiFePO4 battery. It is limited by a fuse, depending on how many amps your alternator puts out, so that you don’t fry your alternator while charging, and the current is only allowed to flow in one direction, so it won’t flow backwards from the battery back to the alternator to damage it that way either.
To complete the indoctrination to all things Victron, I’ve added a BMV-712 Battery Monitor to my DC panel so I’ll know what’s going on with loads coming in and leaving my boat. You can add an additional charger to the system, but I don’t think I’ll have to. Time will tell, but so far it seems to be working well.
I’ve also added a Victron Galvanic Isolator because when I was following the wires around my boat I realized that the ground wire from the AC side which was attached to the fuel tank lead to nowhere. Upon further consultation with my Nigel Calder book, I learned that it needed to be connected to the boat’s ground and that I needed to put a galvanic isolator between the AC ground and DC ground.
Here’s everything tucked inside an old battery box I picked up at Minney’s in Newport Beach. Starting from the battery and going clockwise: Victron Smart LiFePO4 100 Ah battery, 100amp fuse, Smart Battery Protect 12/24 220, Smart BMS CL 12-100, Shunt for BMV-712, DC negative distribution bus bar.
Here’s a better look at the Smart BatteryProtect 12/24 220 (inside the box), the Smart BMS CL 12-100, the shunt and the negative distribution bus.
Here’s an old dagger board that I found stuck in a crevice of the boat which I have used as a mounting board for my galvanic isolator, DC positive distribution bus bars, and fuses.
DC positive switched and un-switched distribution bus bars, fuses, and Galvanic Isolator mounted alongside the starter batteries.
Another view of everything mounted.
My version of a schematic. Many apologies to any real electricians out there. This is the way it makes sense to me.
Again, my sketch of all of the components without wires.
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