Start battery charging

[Simi 60]

I think that's your problem. Trying to recharge a pretty hefty bank with a small, not-configured-correctly alternator...

Obviously you don't want to spend a ton of money (we ALL get that)... Balmar reg's/alt's are out of the price range... What about a Wakespeed regulator?

Like I said, still going to be $1000 or more including cables for a wakespeed landed here plus $500+ for a yum cha alternator.
And then, it only does something when the engine is running

I'd rather add 2kw of solar to the 2.5kw we have now , far more efficient and far better bang for $$

 

[catalinajack]

Like I said, still going to be $1000 or more including cables for a wakespeed landed here plus $500+ for a yum cha alternator.
And then, it only does something when the engine is running

I'd rather add 2kw of solar to the 2.5kw we have now , far more efficient and far better bang for $$

We get that you don't want to spend money on a component that will not be used often. But, you have thrown good money away on THREE internally-regulated alternators so you must see some value of having an alternator that charges your batteries. You either must spend the coin on a good externally-regulated alternator or continue to burn up alternators. So, go ahead, install another dumb alternator and report back to us how long it lasted. You have a large battery bank. Your dumb alternators will mindlessly put out max amps trying to charge that bank until it burns itself up, AGAIN. Seems a waste to me but it's your money. You can't have it both ways.

 

[Simi 60]

Am I missing something here? Multiple alternators blew up charging the house bank. This is a role that they are not rated for (undersized) and not needed (solar and/or genset) are sufficient. This is only going to get worse once LA are swapped for LFP.
.

When we got her there was a 45 amp alt on connected to VSR and house.
That worked well but looking back, died when doing a night passage when batteries were drained.

I never cottoned on as to the why and replaced the alt with a bigger unit and it to worked fine during the day, but died again on a night passage when batts were down

This alt claimed to be continuous rated
Clearly continuous means something different

Isn't the answer just to disconnect the alt charging of the house bank. One assumes that just charging the start bank it lives a happy life.

Yes, ......now that is obvious and what I have been saying
I have no want or need to charge house bank with an alt.
But the alt is dead and this post was about do I get another alt or am I better off with a victron smart charger

I have now purchased the Victron.

 

[Simi 60]

We get that you don't want to spend money on a component that will not be used often. But, you have thrown good money away on THREE internally-regulated alternators so you must see some value of having an alternator that charges your batteries.

No
At this stage I haven't spent a cent on alternators
1 was on the boat when we got it
2 was purchased and refunded under warranty as not fit for purpose
And I was here debating if 3 was worth doing

Clearly it is not
.

You either must spend the coin on a good externally-regulated alternator or continue to burn up alternators. So, go ahead, install another dumb alternator and report back to us how long it lasted. You have a large battery bank. Your dumb alternators will mindlessly put out max amps trying to charge that bank until it burns itself up, AGAIN. Seems a waste to me but it's your money. You can't have it both ways

.

Maybe go back and read the thread again

 

[FF]

" $1000 plus
I don't need that expenditure to charge a 24v batt."

The problem is underway at night you need more amps than the existing alt is able to produce.

A 135A large frame truck alt ($150 US) MIGHT be enough for the power draw, the suggested DN 50 at about 250A will surely be enough.

Since the DN 50 would be purchased used and rebuilt it is the lowest cost option for really big amps.

Lower cost plan B might just to run the genset for a 4 hour trip.

 

[Simi 60]

The problem is underway at night you need more amps than the existing alt is able to produce..

Does it matter as long as I have battery sufficient to get me through till the sun comes up?
Or I hit the button on the genset if needed
With the lifepo4 I am installing I could probably go several days before needing a top up

A 135A large frame truck alt ($150 US) MIGHT be enough for the power draw, the suggested DN 50 at about 250A will surely be enough.

Its a $1000 alt in Australia
Has it the same mount as needed for my motor? (No it has not)
How much to modify? (probably $500 if paying someone)
And I bet ill still need a $1000 wakespeed or similar eh?
So $2500?

And it still only generates power for the few hours a week that the main engine is running - ECONOMICAL FAIL

Since the DN 50 would be purchased used and rebuilt it is the lowest cost option for really big amps.

No, the existing genset is by far the cheapest source of power in the dark
The existing 2500 watts of solar is by far the cheapest source of power in the light

Lower cost plan B might just to run the genset for a 4 hour trip

Hallelujah
$10 in diesel Vs $2000 in "smart" alternators - no contest

 

[OldDan1943]

Push start the boat?

He asked for suggestions and ideas, he got them.
Sounds like he has made up his mind so no use trying to change it. SHRUG

 

[Simi 60]

Push start the boat?

He asked for suggestions and ideas, he got them.

Why would I need to push start the boat with fully charged 24/7 starts?

You haven't come up with a logical solution that betters a smart charger
If you have one, that is economically viable, please continue

Sounds like he has made up his mind

As stated several posts ago.
Smart charger is purchased.

 

[OldDan1943]

Why would I need to push start the boat with fully charged 24/7 starts?

You haven't come up with a logical solution that betters a smart charger
If you have one, that is economically viable, please continue



As stated several posts ago.
Smart charger is purchased.

I guess you are waiting for all of us to come to with the same logical conclusion as you. SHRUG
I wish you well with your SmartCharger.

 

[Simi 60]

I guess you are waiting for all of us to come to with the same logical conclusion as you. SHRUG
I wish you well with your SmartCharger.

Have you any explanation why it wont work?

Please, educate me

 

[OldDan1943]

Have you any explanation why it wont work?

Please, educate me

None what so ever.
I still recommend putting an alternator on the engine to charge the start battery.
Per the house batteries, the smart charger should do well.
Your generator has isolated (from the rest of the charging system) so why not your start battery and your house batteries?
We all have the parallel switch that will cover the unusual times.

 

[Simi 60]

None what so ever.
I still recommend putting an alternator on the engine to charge the start battery.
Per the house batteries, the smart charger should do well.

Yeah, I dont think you get it.

No, the house batteries wont do well at all with that small victron smart charger

The house batteries are 800+ ah
The victron smart charger is 12 amp
It'd take weeks to charge the house bank

That's why we have a real charger
2500 watts of solar
95 amp mppt
120 amp charger on the Victron inverter charger
and a 7.5 kva genset as backup

 

[OldDan1943]

Guess I dont get it.
I have 800 amp worth of batteries, 3X200amp house and 1x200amp start battery
I have a totally isolated start battery for my generator.
I have the parallel switch of last resort.
A 150amp engine driven alternator.
2X130amp of solar panels.d
Works fine for me.
As I said, I wish you good luck and fortune. SMILE

 

[mahal]

The OP stated clearly that he was considering either replacing his alternator to feed just the start bank or do away with the alternator and instead install a dedicated charger for said bank. He also mentioned that he was leaning towards option 2 and added that an expensive alternator set up wasn't a consideration.

I believe he (I as well) was looking for a compelling reason against his plan and found none, therefore he is proceeding. Post #2 from OC Diver proves that his intended set up will work. How can you argue with having your start bank charged/monitored 24/7 by a smart charger vs. a traditional alternator that will do its job only when underway and cost him more. Of course having both would be nice for redundancy but that can also be achieved by having a spare charger for simplicity and economics. If you really desire a back-up.

For what it's worth, I operated my boat for almost 2 years with a dead alternator with no ill effects. It has been rebuilt since but since we run our generator for 3 hours a day, I doubt it made a difference. Is it possible that there are boats that don't really need alternators?

 

[mvweebles]

Guess I dont get it.
I have 800 amp worth of batteries, 3X200amp house and 1x200amp start battery
I have a totally isolated start battery for my generator.
I have the parallel switch of last resort.
A 150amp engine driven alternator.
2X130amp of solar panels.d
Works fine for me.
As I said, I wish you good luck and fortune. SMILE

Not to be an interloper during a lovers quarrel, but will point out that Simi has 800ah battery bank @24v, so 2x size.

Simi - question: I totally get that a giant alternator with regulator to charge massive house bank is expensive. And that cabling a dc-dc charger is expensive. Maybe I missed it, but isolating the start batteries and replacing with a basic alternator just to starter bank wouldn't work? 240vac charger obviously works fine, just trying to understand the options.

Good luck. Sounds frustrating.

Peter

 

[ranger58sb]

Maybe I missed it, but isolating the start batteries and replacing with a basic alternator just to starter bank wouldn't work? 240vac charger obviously works fine, just trying to understand the options.

I think that was my post #8 and his post #11.

-Chris

 

[Iggy]

I still think is worthwhile to determine why three alternator have failed.

A 70 amp Alt sounds too small. My own boat has a 125 amp alt but what do I know? Which chargers the house 540 ah and the starting which is 8D size. Can't remember the amp hours. But if your house batteries are low a 70 amp alt will burn up very quickly.

Because of this, I start my genset and let the charger do some of the bulk charging. So for 20 minutes or so. Than start the engine and let the Alt take over putting less stress on the Alt.

 

[OldDan1943]

A 70 amp Alt sounds too small. My own boat has a 125 amp alt but what do I know? Which chargers the house 540 ah and the starting which is 8D size. Can't remember the amp hours. But if your house batteries are low a 70 amp alt will burn up very quickly.

Because of this, I start my genset and let the charger do some of the bulk charging. So for 20 minutes or so. Than start the engine and let the Alt take over putting less stress on the Alt.

On my Cummins 5.9 the alternator is 150amps. So far, I have not experienced any problem.
My start battery stays charged when at the dock.
Underway, the main and the house batteries seem to remain charge. The 2X130amp solar panels seem to help topping off the batteries too.
The generator battery is totally divorced from all charging circuits. I am thinking about adding a circuit to parallel the gen battery to the house just in case the gen battery goes flat and cant start.

 

[Simi 60]

The OP stated clearly that he was considering either replacing his alternator to feed just the start bank or do away with the alternator and instead install a dedicated charger for said bank. He also mentioned that he was leaning towards option 2 and added that an expensive alternator set up wasn't a consideration.

I believe he (I as well) was looking for a compelling reason against his plan and found none, therefore he is proceeding. Post #2 from OC Diver proves that his intended set up will work. How can you argue with having your start bank charged/monitored 24/7 by a smart charger vs. a traditional alternator that will do its job only when underway and cost him more. Of course having both would be nice for redundancy but that can also be achieved by having a spare charger for simplicity and economics. If you really desire a back-up.

For what it's worth, I operated my boat for almost 2 years with a dead alternator with no ill effects. It has been rebuilt since but since we run our generator for 3 hours a day, I doubt it made a difference. Is it possible that there are boats that don't really need alternators?

Glad someone understands

 

[OldDan1943]

My Cummins 5.9 QSB needs 'electricity' to run. Without it, the engine does shut down. I know!!
I can start the gen to keep the house and start batteries charged.

 

[mvweebles]

I think that was my post #8 and his post #11.



-Chris

Thanks. I don't see a problem with a charger of some sort, but I also don't see a problem with an alternator isolated to just start/windlass bank - I would think it solves problem of alternator burnt-out due to charging a relatively large house bank. I understand alternator only charges while engine is running, but the connected batteries (start/windlass) only discharge when engine is running so mass-balance equals out.

Just trying to understand.

Peter

 

[Simi 60]

Thanks. I don't see a problem with a charger of some sort, but I also don't see a problem with an alternator isolated to just start/windlass bank - I would think it solves problem of alternator burnt-out due to charging a relatively large house bank. I understand alternator only charges while engine is running, but the connected batteries (start/windlass) only discharge when engine is running so mass-balance equals out.

Just trying to understand.

Peter

If you already have a working alternator great
If you don't here is the explanation again courtesy of mahal

.

I believe he (I as well) was looking for a compelling reason against his plan and found none, therefore he is proceeding. Post #2 from OC Diver proves that his intended set up will work. How can you argue with having your start bank charged/monitored 24/7 by a smart charger vs. a traditional alternator that will do its job only when underway and cost him more. Of course having both would be nice for redundancy but that can also be achieved by having a spare charger for simplicity and economics. If you really desire a back-up.

 

[mahal]

Glad someone understands

Simi, I’ve watched all episodes of Kath and Kim as well as Rake. So I might understand Australian a little better than others here

 

[BruceK]

Push start the boat?

Not as odd as it sounds, there was a cruise ferry on Sydney Harbour with a start issue, they used to tow it out of gear,and drop it into gear,to get it started.

 

[OldDan1943]

Not as odd as it sounds, there was a cruise ferry on Sydney Harbour with a start issue, they used to tow it out of gear,and drop it into gear,to get it started.

They only had to do it once, if they never shut off the engines

 

[ranger58sb]

Thanks. I don't see a problem with a charger of some sort, but I also don't see a problem with an alternator isolated to just start/windlass bank - I would think it solves problem of alternator burnt-out due to charging a relatively large house bank. I understand alternator only charges while engine is running, but the connected batteries (start/windlass) only discharge when engine is running so mass-balance equals out.

Just trying to understand.

My similar suggestion was only because I want an alternator charging its engine's battery regardless, just general principles.... and because I like redundancy to the extent practical.

I think Simi is more interested in the best of the potential "least expensive" solutions, entirely reasonable.

-Chris

 

[GoneDiving]

They only had to do it once, if they never shut off the engines

You beat me to it.....In a past life, I may have left trucks running for days on end waiting for spare parts ?

 

[La Sirena]

Why can't you make it through the night with a 880A-hr 24V bank? That's like 8 4D 12V AGM batteries. What is your electrical load at night?