What are the best Lithium Marine Batteries for house and engine batteries

[florin]

Hi Bert
I'm also curios to see how the sugar "battery" story unfolds. Sugars are the energy carriers just about anything living uses so off to a good start. Not sure why they call it a battery though as it's clearly a fuel cell. The competition, if any will be with hydrogen, methanol or other synthetic compound fuel cells, not lithium or other batteries.

 

[BertKu]

Hi Bert
I'm also curios to see how the sugar "battery" story unfolds. Sugars are the energy carriers just about anything living uses so off to a good start. Not sure why they call it a battery though as it's clearly a fuel cell. The competition, if any will be with hydrogen, methanol or other synthetic compound fuel cells, not lithium or other batteries.

I basically agree with you.
Bert

 

[John Perry]

John, all Honda and Yamaha portable generators make and have outputs for 12v, they also turn that 12v into 120v. I am working on plans for an outboard cruiser that has a pair mounted in cabinets in the cockpit with access doors that open in the transom to the swim step. All the noise and exhaust goes overboard since it is never in the boat. The Hondas and Yamahas can be paired to double their output and the larger ones are remote start with fuel pumps for direct connection the boats tanks. The larger of my own gensets is 2.4kw and weighs 60lbs. Not to be confused with the cheap contractor generators available at Home Depot or Lowes, those are like an old-fashioned marine genset in that they run at high rpm all the time. At light loads like you describe, either of my gensets just purrs and is barely audible if in a sound shield.

I am not sure you understand my point. Sure, Honda and Yamaha both make small petrol generators that have 12v outputs, but these low voltage outputs dont seem to be suitable to take full advantage of the high charge rate possible with lithium batteries. Taking the Yamaha EF1000iS as typical of the small end of the range, this generator has close to 1kW maximum 230V AC output but only 8amps maximum output at 12V. Say you have a nominal 100amp-hour lead acid battery, or alternatively a nominal 62 amp-hour lithium battery, these being about equivalent in their effective capacity. Its going to take several hours to fully charge either type of battery from the DC output of this generator, whereas if you had a generator that could put the full power of the same petrol prime mover into generating at low voltage you could charge the lithium option in about one hour. This would reduce the time that you have to put up with the noise and reduce the fuel usage. Of course, you could alternatively put the AC output of the generator through a battery charger, but that would seem to be a more roundabout way to do it and it would need to be a big battery charger, battery chargers carried on small boats normally only being intended for overnight charging at fairly low current from shore power.

 

[groper]

Wouldn't hard to make up a home made gizmo I would think... First a transformer to bring down the 240v down to 14v, then a bridge rectifier with high current diodes and then some capacitors to even out the voltage bumps. Probably need some means of governing the load as the internal resistance of the lithium battery is very low. Plug this into the 240v outlet of the genny and bingo?

 

[pdwiley]

Wouldn't hard to make up a home made gizmo I would think... First a transformer to bring down the 240v down to 14v, then a bridge rectifier with high current diodes and then some capacitors to even out the voltage bumps. Probably need some means of governing the load as the internal resistance of the lithium battery is very low. Plug this into the 240v outlet of the genny and bingo?

Funnily enough I have one of those big rectifiers. Long time ago before the advent of cheap DC welders CIG sold a big AC-DC box you could attach to your stick welder. You could then do a scratch start TIG job (not aluminium though) if you had to, or run DC rods.

Mine has been sitting under a bench in search of a purpose for years now. Perhaps I should think about selling it. I'll never use it again (famous last words).

PDW