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

[john61ct]

My reference to a Primary/Reserve bank design has nothing to do with the usual idea of a "starter" batt.

Which of course you've been around long enough to know very well already.

[newhaul]

Originally Posted by john61ct

My reference to a Primary/Reserve bank design has nothing to do with the usual idea of a "starter" batt.

Which of course you've been around long enough to know very well already.

you also know that the majority of us that are actually running Lfp house banks any lead is regulated to starting and buffering for alternator output diode protection . IOW an automotive type starting battery, not a deep cycle type battery which is not optimized for starting use.
Myself I will only be using a small 500 +/- cca Fla battery to start my diesel and protect my alternator in the event of an unlikely HVD situation .

[john61ct]

I believe this might be relevant? Gibbo is one smart fellow.

http://www.smartgauge.co.uk/batt_con.html

How far is it necessary to go to get the matching equal?

Well, the better the quality of the batteries, the more important it becomes. The lower the internal resistance of the batteries, the more important it is to get them properly balanced.

[john61ct]

Originally Posted by newhaul

automotive type starting battery, not a deep cycle type battery which is not optimized for starting use

Again, nothing to do with a proper Reserve bank, was not even thinking of lead.

But, never mind for now.

[Q Xopa]

Originally Posted by john61ct

Common as chips, but good stuff not as cheap.

Seems to me you should go 24V throughout.

Little low-watt for specific PoL circuits are IMO better than multiple backbones.

eBay is a great source for industrial quality NOS but recently discontinued, get the datasheets off Mouser or Digikey.

Seen no-reserve auctions of pallet loads of say TDK-Lambda converters end up going for under a dollar each, sellers just clearing the warehouse eat most of the shipping too.

Yes agreed I'd like to go all 24V. We almost, some things just dont come in 24V. Thats fine I can use 24-12v convertors for these.

You are obviously a better online searcher than me because I couldnt find any 24V Yanmar 4JH4 compatable Starter motors.

Any links?

[john61ct]

No, I interpreted this

Originally Posted by Q Xopa

with my 24v house/ windlass and 12v start arrangement its not so simple.

to mean already in place.

Find a junked 12V one and get a clever shop to rewind the guts? Really outside my wheelhouse though.

So why did you go 24V House?

[Q Xopa]

Originally Posted by john61ct

No, I interpreted thisto mean already in place.

Find a junked 12V one and get a clever shop to rewind the guts? Really outside my wheelhouse though.

So why did you go 24V House?

Yes asked some shops about doing Starter motor rewinds. I cant find guys that do this these days. Many used to but doesnt seem to be done as much any more.

Gone 24v mostly for 2x 3,000W Inverters and a 1,200W Windlass on the bow. This is 50A CB and 4AWG upto 140ft cable run (3/0 for 12v) for a max 10% voltage
drop.

I assumed you would understand the reasons to go 24v over 12v.

[newhaul]

Originally Posted by john61ct

Again, nothing to do with a proper Reserve bank, was not even thinking of lead.

But, never mind for now.

ok I see you are thinking of doing similar to what I am except not using a lead based starter battery so you are thinking Lfp throughout?

Personally I want lead in the start position to serve as a buffer for the alternator if nothing else

[newhaul]

Originally Posted by Q Xopa

Yes agreed I'd like to go all 24V. We almost, some things just dont come in 24V. Thats fine I can use 24-12v convertors for these.

You are obviously a better online searcher than me because I couldnt find any 24V Yanmar 4JH4 compatable Starter motors.

Any links?

here is a possible
https://m.go2marine.com/controller?f...anmar+Starters

[Q Xopa]

Originally Posted by newhaul

here is a possible
https://m.go2marine.com/controller?f...anmar+Starters

Ive actually asked them previously. They didnt have the right ones then. Not sure if your link is the same
I'll ask again.

Many Thanks.

[newhaul]

Originally Posted by Q Xopa

Ive actually asked them previously. They didnt have the right ones then. Not sure if your link is the same
I'll ask again.

Many Thanks.

worst case talk to a heavy equipment repair shop they are almost always 24 volt starters .
They may have an idea for you to pursue.

[john61ct]

Originally Posted by Q Xopa

I assumed you would understand the reasons to go 24v over 12v.

Sure but there are always trade-offs.

A pre-existing 24V engine setup would be a big push in that direction.

[Q Xopa]

Originally Posted by john61ct

Sure but there are always trade-offs.

A pre-existing 24V engine setup would be a big push in that direction.

Im not sure what you mean by 'pre existing' ?

My Yanmar 4JH4-TE is 12v. Most motors, that Im aware of, in our HP category, are 12v.

Yes I agree having my Starter batt 24v would be my preference. If/when, I can find a Starter or get them rewound I will do just that.

[john61ct]

I misunderstood, inferred that you already had that in place, and the current project was figuring out the few remaining islands of 12V required.

[Dockhead]

Originally Posted by newhaul

ok I see you are thinking of doing similar to what I am except not using a lead based starter battery so you are thinking Lfp throughout?

Personally I want lead in the start position to serve as a buffer for the alternator if nothing else

I have dual alternators on the main engine, and my main and gen start systems are 12v.



So I can't "buffer" the second alternator with a start batt, nor would I want to eliminate the desirable total separation of these systems.


So I am planning to use one of these to protect the alternator:


https://sterling-power.com/products/...tection-device


Do you see any reason why this wouldn't work?