Advice Requested re Conversion to LFP House Bank

[john61ct]

Or consider, just a reminder that just fitting a Sterling B2B DCDC charger eliminates the need to make any changes at all to your alternator setup, just keep everything stock.

Then use the LFP for a while see how that works for you with your usage patterns, combination of other energy inputs, you may well have plenty of Ah per day and maybe never need to upgrade your alt or VR.

The DCDC stays with your LFP when you want to use it elsewhere, e.g. go to another boat.

And can be used to condition any DC source input, not just your alt's.

Not saying this alternative is necessarily "better" than messing with your alt setup, just that it is an alternative, worth considering.

[newhaul]

Originally Posted by john61ct

Or consider, just a reminder that just fitting a Sterling B2B DCDC charger eliminates the need to make any changes at all to your alternator setup, just keep everything stock.

Then use the LFP for a while see how that works for you with your usage patterns, combination of other energy inputs, you may well have plenty of Ah per day and maybe never need to upgrade your alt or VR.

The DCDC stays with your LFP when you want to use it elsewhere, e.g. go to another boat.

And can be used to condition any DC source input, not just your alt's.

Not saying this alternative is necessarily "better" than messing with your alt setup, just that it is an alternative, worth considering.

yea that is a valid option however why do you want to throttle down your alternator output like that .
If you do want to go that route renogy makes a similar unit but at about half the cost and yes its considered good for a marine environment .
Now as to your Lfp bank and associated charging systems once on a boat don't usually get removed and reinstalled on another boat.
You sell your boat . When you get a new boat you want to put new bank and new chargers on it not the old stuff that is/ was part of the installed system on the previous boat.

( would love to hear that conversation . " when you buy the boat it will need batteries and a new charging system because I'm taking the current system with me "

[john61ct]

Not advocating for one context, just laying out the options. Alternator may not even be the main energy input in many cases.

The power systems could be worth more than the boat.

Designing for portability is easy with LFP, and can be very useful for many off-grid living scenarios, even if you never sell the boat.

Smaller packs for powering the dink is another.

Going for a huge alt setup and also having uses for a DCDC is possible too.

wrt the new Renogy, that's 40A right? Did that turn out to have user-custom setpoints? I forget.

To me that last is a deal-breaker for LFP.

[newhaul]

Originally Posted by john61ct

Not advocating for one context, just laying out the options. Alternator may not even be the main energy input in many cases.

The power systems could be worth more than the boat.

Designing for portability is easy with LFP, and can be very useful for many off-grid living scenarios, even if you never sell the boat.

Smaller packs for powering the dink is another.

Going for a huge alt setup and also having uses for a DCDC is possible too.

wrt the new Renogy, that's 40A right? Did that turn out to have user-custom setpoints? I forget.

To me that last is a deal-breaker for LFP.

actually the 60 amp unit is expected to be available by the end of summer .
Yes it is user wearable I posted the pages of the manual on another thread .

[john61ct]

User wearable?

Found my notes:

New Renogy DCDC

Definitely not allowing custom setpoints, only a limited set of canned profiles.

Uniquely requires an external switch, really designed for Alt-only charging tied to IGN,

in other contexts, by default will run down the bank on the source side when no charge source is active, not auto voltage sensing.

No mention in writing of any IP water resistance rating.

Only warranty mentioned is the "statutory" minimum, great if you're in Australia, stateside not so much.

But may turn out to be very reliable, they do have great CS attitude and a good reputation to uphold.

[newhaul]

Originally Posted by john61ct

User wearable?

Found my notes:

New Renogy DCDC

Definitely not allowing custom setpoints, only a limited set of canned profiles.

Uniquely requires an external switch, really designed for Alt-only charging tied to IGN,

in other contexts, by default will run down the bank on the source side when no charge source is active, not auto voltage sensing.

No mention in writing of any IP water resistance rating.

Only warranty mentioned is the "statutory" minimum, great if you're in Australia, stateside not so much.

But may turn out to be very reliable, they do have great CS attitude and a good reputation to uphold.

some day you ought to actually do any of the stuff you post about so you can get practical experience.

[Delfin]

Originally Posted by newhaul

some day you ought to actually do any of the stuff you post about so you can get practical experience.

Perhaps, bit think how much cheaper it is to not actually own any of the equipment you pose as a user expert in.

[Q Xopa]

Originally Posted by jmardiat

Thanks again for all of your considered input.

Xopa has nicely restated my current setup. I am leaning towards purchasing a small case Balmar 6 series alternator w/regulator kit. The 70 Amp and 100 Amp versions are the two most reasonable choices. I suspect that I will be better off with the 100 Amp unit but is there a price to pay beyond cost, such as power loss from increased alternator drag? Or, is that insignificant?

Yes agreed with doing an External Regulation conversion.

Along those lines, you mentioned buy a Balmar 6 alternator. They are certainly good, but not cheap. If it were me I would simply buy another the same as comes standard but with a higher output. A quick google has small case 140A alts for $230. Im sure there any number to be found.

Extra drag on your Engine. Yes sure, although as others have said most people get LFPs because they dont have to charge them to full and the charge fast and efficiently. As you say that takes some engine power. To most people thats a desirable trait. Ie it loads your engine so it doesnt coke up or glaze bores and better fuel efficiency etc.

[Q Xopa]

Originally Posted by john61ct

Or consider, just a reminder that just fitting a Sterling B2B DCDC charger eliminates the need to make any changes at all to your alternator setup, just keep everything stock.

Then use the LFP for a while see how that works for you with your usage patterns, combination of other energy inputs, you may well have plenty of Ah per day and maybe never need to upgrade your alt or VR.

The DCDC stays with your LFP when you want to use it elsewhere, e.g. go to another boat.

And can be used to condition any DC source input, not just your alt's.

Not saying this alternative is necessarily "better" than messing with your alt setup, just that it is an alternative, worth considering.

A B2B doesnt address the possible overheating of an Alternator. Which is what the OP is rightly worried about.

[john61ct]

Yes it absolutely does.

How can you think it doesn't? Just like a VR upgrade, derating the current demanded by the LFP. That's the whole point of buying one in this use case.

Yes, it only has the stepwise preventing in advance part, not dynamically after the fact, based on the overheating happening.

Is that what you mean?

[Q Xopa]

Originally Posted by john61ct

Yes it absolutely does.

How can you think it doesn't? Just like a VR upgrade, derating the current demanded by the LFP. That's the whole point of buying one in this use case.

Yes, it only has the stepwise preventing in advance part, not dynamically after the fact, based on the overheating happening.

Is that what you mean?

I think its like buying a turbo charged car but putting a block under the gas pedal to save your gas and tires.

To me the logical answer is save money and buy a Camry.

You obviously like the idea. Your dime you spend how you like.

But if you can report back with all your findings please.

[john61ct]

Again, you misunderstand, see my #63

[Stu Jackson]

Originally Posted by john61ct

Again, you misunderstand, see my #63

Which was mostly about portability of putting in a new bank.


What does this have to do with what Q Xopa asked?


Or have anything to do with the OP's question?


Temp sensors or smart manual management is necessary to deal with alternator operation, output and heat should always be before the damage-inducing conditions occur.


Ruining alternators is not on my list of preferred options.


For the OP, sorry about the diversion. It happens here and almost everywhere.


I hope you've been reading up and can get back to us on the question about your existing alternator's method of regulation.

[john61ct]

Not advocating for one context, just laying out the options.

But if you find your existing setup is just fine with say 45A continuous output, you just set the DCDC to pull that current and no more, and you're done.

Where that is sufficient, or the alternator is not even the main energy input, that is a simple and maybe more flexible option.

Again, not saying B2B is **the** solution here, just pointing out it is indeed a valid one in some situations..

[weavis]

Side note.

when you sort out the choices before you.. and if you want to use some sub-2-kilowatt appliances that might be a little much for for your bank and inverter, consider buying a Honda generator 2000. In the UK I got on a deal for about £780. It's quiet, powers 230 volts and I think I get about 5 hours run time... So I put petrol in about every 3 weeks. I keep a 2-gallon container of petrol and it seems to last forever. Did I mention it is quiet..?

I have mine set up in a breathable locker in the cockpit, and cable run into the boat to fire up different kitchen appliances as required. I use for the coffee maker, microwave, induction hob, Instant Pot cooker etc. I have a gas hob and oven. Some days I use for up to one hour, and many days I don't use at all... There is a soft start unit on it (extra)so will even fire up an A/C unit if is hot.

A lot cheaper than changing your power system. If I had to make a choice, Id fix the alternator with external regulation and if your batteries are OK.. look at upgrading your solar system and find a good place to put it..

I'm no boat electric wizard, but I like to keep costs to a minimum. Seems to me for the usage you require, what you have is perfectly adequate with a bit of tweaking.

A lot of excellent advice here.