LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[ebaugh]

Originally Posted by Lagoon4us

Our 240 req's are as follows.
1) The planned respective 2 chargers. 1 for lead acids 1 for Lithium. In practice the lead acids will require minimal charging.

2) Hot plate only on shore power/paguro gen set/planned cruise alternator.

3) Air con on shore power/paguro gen set/ planned cruise alternator.

4) De-sal on any 240 source including existing inverter.

5) Small white goods usually on inverter so no engine start up is required.

Do i need a load share or do you think it complicates things? Cheers

I'm going to make some assumptions here...you will need to correct:

Hot Plate (2 burners?) : 2500 watts
AC (one system?) : 1500 watts
DeSal (240V motor): 1500 watts
Small white goods: 500 watts

That's probably maxed out or just overloaded the genset, not that you will run these all together often. Now add:

Battery Charger (only the new one): 1500 watts

Do you have:

Microwave: 1500 watts
Hot Water heater element: 1000-2000 watts
Oven/Convection Oven?: 1000-2000 watts
Electric Grill: 1000-1500 watts
Hair Drier: 1500 watts
Anything else I forgot?

I'm guessing you have 240V 30A or 32A shore power? Would you like to be able to use a 16A shoreside outlet when a bigger one is not available?

The incremental cost is inverter/charger instead of just a charger. In round numbers another what I call a boat unit or 1K. Given the project has to be over 10 boat units already, I'd probably do it.

[Lagoon4us]

The genset as it is now provides 240 volt power to the standard Lagoon board and from there we select generator as the source to the board as against shorepower.
we then switch on the Dolphin 80 Amp Charger to boost the batteries.
Is there a problem doing this when electronics are connected to outlets?
Sorry i don't think i understand?
Cheers Frank

[Lagoon4us]

Originally Posted by ebaugh

I'm going to make some assumptions here...you will need to correct:

Hot Plate (2 burners?) : 2500 watts
AC (one system?) : 1500 watts
DeSal (240V motor): 1500 watts
Small white goods: 500 watts

That's probably maxed out or just overloaded the genset, not that you will run these all together often. Now add:

Battery Charger (only the new one): 1500 watts

Do you have:

Microwave: 1500 watts
Hot Water heater element: 1000-2000 watts
Oven/Convection Oven?: 1000-2000 watts
Electric Grill: 1000-1500 watts
Hair Drier: 1500 watts
Anything else I forgot?

I'm guessing you have 240V 30A or 32A shore power? Would you like to be able to use a 16A shoreside outlet when a bigger one is not available?

The incremental cost is inverter/charger instead of just a charger. In round numbers another what I call a boat unit or 1K. Given the project has to be over 10 boat units already, I'd probably do it.

Not far off however we judiciously select what we run at any given time, we work the genset hard but don't go into overload.

No oven no grill no hairdryers.

Aircon is only on in marinas.

Shorepower here is around 10 amp no more than 15 unless you go into the expensive pens.

A normal usage in 24 hrs for us will be:-
Cook top runs 1.5 hrs. on gen or shore
Microwave three times. on gen or shore
Jug 6 times on inverter or other.
Toaster once on inverter.
Battery charger constantly on if connected to shorepower. genset started as needed.
DeSal ran every three days, on inverter or 240 by whatever source.
TV by any source three hours.

As i said we are careful as to what we run together the Lithium builds our inverter usage and the solar hopefully will cope 70% of time for nav/lighting/pumping/inverter.

[Lagoon4us]

Originally Posted by ebaugh

I'm going to make some assumptions here...you will need to correct:

Hot Plate (2 burners?) : 2500 watts
AC (one system?) : 1500 watts
DeSal (240V motor): 1500 watts
Small white goods: 500 watts

That's probably maxed out or just overloaded the genset, not that you will run these all together often. Now add:

Battery Charger (only the new one): 1500 watts

Do you have:

Microwave: 1500 watts
Hot Water heater element: 1000-2000 watts
Oven/Convection Oven?: 1000-2000 watts
Electric Grill: 1000-1500 watts
Hair Drier: 1500 watts
Anything else I forgot?

I'm guessing you have 240V 30A or 32A shore power? Would you like to be able to use a 16A shoreside outlet when a bigger one is not available?

The incremental cost is inverter/charger instead of just a charger. In round numbers another what I call a boat unit or 1K. Given the project has to be over 10 boat units already, I'd probably do it.

Lol i agree about the 'boat unit' should become standard terminology!!!!

[Hyprdrv]

Frank when a large load is placed on the system, like a genset starting, the draw on the battery(s) can be enough to damage some sensitive electronics like chart plotters. Add loads like mentioned above and start the genset and it can pull down the voltage enough to kick off the Sensitive Electronics for a few seconds and restart. Just not a good thing and kind of a side bar to the topic. You hadn't mentioned the Genset start battery and I was wondering if you had missed it in your system design.
It doesn't appear to be an issue in this case.

Steve in Solomons MD

[hellosailor]

"What is a BMS? If it includes"
I don't know what a BMS is, how long is a piece of string?
A battery management system (BMS) can include or exclude anything it wants. I suppose I could sell you a good tie-down strap and some bolts and say that's "battery management" it manages to keep them secured to the boat.

If proprietary lithium makers weren't so busy sniping at each other, they'd form a trade organisation, work up some standards, put on a uniform front and remember that a rising tide floats all ships. All the pissing fights and arguments about whether you really MUST double the battery price by adding charge controls...just makes a wet floor and encourages me to look elsewhere.

Surely the lithium battery makers can't all be newbies with no real marketing or battery experience? JCI, Lifeline, Varta, Deak/East Penn...all have no dog in the fight, do they? Hmmm.

[Lagoon4us]

Ahh i understand, i'm dedicating the two mains and thruster and genset "the lead-acid family" to just starting and thrusting, me-thinks with all the spare cable i'll have leftover from removing the 'house' acid family i should run a simple selector switch so in the event of a flat batt i can flick a switch.

The only heavy loads not accounted for in your heads up would be the anchor and sheet winches, i know the anchor winch requires the port side engine to be running (which is the dumbest thing LAGOON ever come up with) so i need to do a quick check as to where all winch power comes from house or start???

[ebaugh]

Originally Posted by hellosailor

"What is a BMS? If it includes"
I don't know what a BMS is, how long is a piece of string?
A battery management system (BMS) can include or exclude anything it wants. I suppose I could sell you a good tie-down strap and some bolts and say that's "battery management" it manages to keep them secured to the boat.

If proprietary lithium makers weren't so busy sniping at each other, they'd form a trade organisation, work up some standards, put on a uniform front and remember that a rising tide floats all ships. All the pissing fights and arguments about whether you really MUST double the battery price by adding charge controls...just makes a wet floor and encourages me to look elsewhere.

Surely the lithium battery makers can't all be newbies with no real marketing or battery experience? JCI, Lifeline, Varta, Deak/East Penn...all have no dog in the fight, do they? Hmmm.

The only ones selling to the DIY marine market are Chinese, and at the moment, it's a tiny fraction of their sales. I believe though in general, they will tell you some sort of BMS is needed. My supplier would not warranty the cells without one, but I don't know if that's universally true.

[ebaugh]

Originally Posted by Lagoon4us

Ahh i understand, i'm dedicating the two mains and thruster and genset "the lead-acid family" to just starting and thrusting, me-thinks with all the spare cable i'll have leftover from removing the 'house' acid family i should run a simple selector switch so in the event of a flat batt i can flick a switch.

The only heavy loads not accounted for in your heads up would be the anchor and sheet winches, i know the anchor winch requires the port side engine to be running (which is the dumbest thing LAGOON ever come up with) so i need to do a quick check as to where all winch power comes from house or start???

Yes...follow the breakers...that may be the easiest way to spot.

[Lagoon4us]

Originally Posted by ebaugh

Yes...follow the breakers...that may be the easiest way to spot.

Can you imagine having to start the port engine to pull the anchor up?
It must be running to do so not just switched on?

On a sailboat mind you, nothing said about if the motor is U/S at the time.

On our past boats we would sail off or on the anchor NEVER wanting or needing to start an engine to do so.....

The cabling on these boats is largely unmarked and heavily bundled, i think i'll disconnect power sources to figure it out, just haven't had the need to know as yet...

Cheers

[ebaugh]

Originally Posted by Lagoon4us

The genset as it is now provides 240 volt power to the standard Lagoon board and from there we select generator as the source to the board as against shorepower.
we then switch on the Dolphin 80 Amp Charger to boost the batteries.
Is there a problem doing this when electronics are connected to outlets?
Sorry i don't think i understand?
Cheers Frank

I don't know exactly how the existing inverter is wired. Can you run (or at least attempt to) run every AC load on it? If so, it probably looks something like the Victron in this picture. If not, there may be a sub panel for those loads. The MSP2012 has a transfer switch, but the manual does not identify its rating that I could find. I would be skeptical running the whole house through the MSP2012.

But the left side of this diagram shows one way to incorporate the Cruise gen, and the right side is how you would wire in the Victron Multi if you go that route. Otherwise, all that side remains the same.

[ebaugh]

Wrong version of picture....Updated here.

[ebaugh]

Originally Posted by Lagoon4us

Can you imagine having to start the port engine to pull the anchor up?
It must be running to do so not just switched on?

On a sailboat mind you, nothing said about if the motor is U/S at the time.

On our past boats we would sail off or on the anchor NEVER wanting or needing to start an engine to do so.....

The cabling on these boats is largely unmarked and heavily bundled, i think i'll disconnect power sources to figure it out, just haven't had the need to know as yet...

Cheers

Almost has to be an oil pressure switch on the port engine that closes a solenoid. Or possibly something that senses charge voltage sensed near the port alternator.

I guess they do it that way to maximize the voltage at the windlass motor. I've heard of this being done on some boats. If you had lots of chain out and a single weak battery you might not get the engine started. It also smells of a bareboat charter design...

[ebaugh]

Originally Posted by Lagoon4us

Not far off however we judiciously select what we run at any given time, we work the genset hard but don't go into overload.

No oven no grill no hairdryers.

Aircon is only on in marinas.

Shorepower here is around 10 amp no more than 15 unless you go into the expensive pens.

A normal usage in 24 hrs for us will be:-
Cook top runs 1.5 hrs. on gen or shore
Microwave three times. on gen or shore
Jug 6 times on inverter or other.
Toaster once on inverter.
Battery charger constantly on if connected to shorepower. genset started as needed.
DeSal ran every three days, on inverter or 240 by whatever source.
TV by any source three hours.

As i said we are careful as to what we run together the Lithium builds our inverter usage and the solar hopefully will cope 70% of time for nav/lighting/pumping/inverter.

I'm almost afraid to ask what a Jug is...shows I'm a Yank....we use that term for other things...

I'm not sure how often you go to the pens (marina), but if you normally can only get the 10 or 12A circuit, the Victron will help. Run most anything you want and it will keep the shore power usage limited to what's available. You will also end up with a spare inverter in a box for emergencies.

I'm not sure what size cruise generator you are buying, but the Victron might allow you to buy a smaller size, unless you are already buying the smallest one. You probably won't notice the smaller cruise generator much underway, but if the main genset was broken and the cruise gen became the primary, it would cause longer runtimes.

You need to price both...100A+ 12V chargers are not inexpensive. And you need a fancier one where you can set custom voltages. I think that might limit the market to Victron and Mastervolt, I'm not sure. Without the Victron load sharing, in the US a Magnum inverter charger is about the same price as a Victron charger only.

It's all a trade off in boat units versus capability. Only you can decide.

[Cotemar]

Originally Posted by Lagoon4us

Can you imagine having to start the port engine to pull the anchor up?
It must be running to do so not just switched on?

On a sailboat mind you, nothing said about if the motor is U/S at the time.

On our past boats we would sail off or on the anchor NEVER wanting or needing to start an engine to do so.....

The cabling on these boats is largely unmarked and heavily bundled, i think i'll disconnect power sources to figure it out, just haven't had the need to know as yet...

Cheers

Lots of Cats require the port engine to be running to use the windless.
Lagoon & Foutaine Pajot are the two big ones