Ideas for the Simplest Lithium Retrofit?

[CaptainMarkS]

I completely agree with segregating the starter battery for only starting the engine. Compromising this is a safety risk.

I also agree with using Orion / Zeus to charge the LFP house from the alternator. DC to DC is easier, though why not harness the engine’s power to more efficiently charge the LFP bank? Another benefit is being able to run the engine at RPMs with appropriate (higher) loads. Lastly, one doesn’t have to run the engine as long to charge batteries, if that’s the primary use occassion.

For those who still think LFP is a “drop-in” solution, check out this video from Ryan and Sophie sailing: https://youtu.be/vraRhNpEWcE?si=fsKLX-KFkGIQm8Mj. 09:20 “Myth #2: I can buy ‘drop in’ lithium batteries.” As the title implies, “drop in” is a myth. Even “only” changing the charging profile means adaptations specifically for lithium batteries.

[newhaul]

Originally Posted by CaptainMarkS

For those who still think LFP is a “drop-in” solution, check out this video from Ryan and Sophie sailing: https://youtu.be/vraRhNpEWcE?si=fsKLX-KFkGIQm8Mj. 09:20 “Myth #2: I can buy ‘drop in’ lithium batteries.” As the title implies, “drop in” is a myth. Even “only” changing the charging profile means adaptations specifically for lithium batteries.

You can say the same about lead based batteries as well.
FLA charging profile is different than AGM and they both are different than GEL. so it doesn't matter what Drop in you purchase you have to set charge profile to match it.

" You have to change the charge profile" is an excuse thrown out by people that want to discourage changing to a better battery Chemestry.

[Pete7]

Originally Posted by NorthCoastJoe

One Lead Gel battery for starting charged from a DC-DC charger from the house bank.

Joe, why have you chosen a gel battery to use as a start battery? An AGM would be far more cost effective surely?

Pete

[senormechanico]

[newhaul]

Originally Posted by Pete7

Joe, why have you chosen a gel battery to use as a start battery? An AGM would be far more cost effective surely?

Pete

Bet it's what he already has on his boat.

[newhaul]

https://www.amazon.com/gp/product/B0...2NBJ69QL&psc=1

Minghong 12.8V 100Ah LiFePO4 Battery Built-in 100A BMS, Deep Cycle Lithium Battery Up to 15000 Cycles,

Considering purchase of this one just to open it up and see how it's built.

[jcapo]

Originally Posted by newhaul

https://www.amazon.com/gp/product/B0...2NBJ69QL&psc=1

Minghong 12.8V 100Ah LiFePO4 Battery Built-in 100A BMS, Deep Cycle Lithium Battery Up to 15000 Cycles,

Considering purchase of this one just to open it up and see how it's built.

$104 delivery Friday, December 20. Details

[newhaul]

Just opened up these boxes .
https://www.amazon.com/dp/B0DBH2KJP3...sin_title&th=1
$200 each delivered
Fired up the Bluetooth and here is what I see
Two batteries not installed yet but putting a charge on them to check top balance

[knutmi]

Originally Posted by newhaul

Please video your alternator as it runs at max for 2+ hours to recharge your depleted house bank.

My VP D-1 have Mitsubishi 115A alternatior charges at max when cold. When warm Amps drop to 80A. It get hot, and it should, cause alternators produce heat when running and producing energy. I have run this setup for 5 years, same Alternator,

[CaptainRivet]

Originally Posted by knutmi

My VP D-1 have Mitsubishi 115A alternatior charges at max when cold. When warm Amps drop to 80A. It get hot, and it should, cause alternators produce heat when running and producing energy. I have run this setup for 5 years, same Alternator,

Yes the Mitsubishi has internal temp protection and doesn't need a DC2DC to limit current.
The AGM regulator gets to 14.2V so you can charge directly lifepo4 with it.
All D1,2 and most D4 Volvos with serpentine belt from 2017 on have this Mitsubishi alternator.
Starts with 100A and slowly scales back to around 80A when the alternator heats up, steering is conservative and alternator doesn't go above 100 degrees celcius.

I cut it off when 13.6V or 3.4V cell voltage reached which you can easily do by just interrupting the sense wire with a little 5 or 10A automotive relay.
Alternative use a victron argofet together with a lead or LTO starter and simple cut the output of the argofet to house with a battery protect 100A. This way the lead starter and LTO gets charged higher and floated by the alternator.
My BMS is steering that.