Start battery charging

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
Simi 60

Simi 60

Guru
Joined
Jul 1, 2016
Messages
5,482
Location
Australia
Vessel Make
Milkraft 60 converted timber prawn trawler
Our engine does not require an alternator to run and the alternator died a a few years ago ago and we happily kept things going on a 24v 4amp port off of our inverter charger

I replaced it earlier this year with a continuous rated large frame 70 amp alternator but alas, it to has now died as it didn't like charging the house bank, apparently continuous rated doesn't mean what I thought it did

So, as the anchor windlass also runs off of the starts I suspect that we could be undercharging them using the 4amp alone even though we do see 27+ v on the battery monitor at times, if disconnecting the 4amp in batts drop back to 24+v

Question here is, if deciding to add a better charge source what would be better?
Spending $300 again on a dumb large frame alt but only have it doing starts and only doing its thing when engine is running?

Or spending a bit less on a dedicated smart charger like this Victron 24v 16amp which will do its thing 24/7?

https://www.springers.com.au/shop/product/bpc241642012-blue-smart-ip22-charger-24-16-1-607

I tend to think option 2 is the better way to go as it's conditioning the battery but thoughts from others more knowledgeable appreciated.

Adding one of those $1000 plus smart balmar alts is never going to happen so forget that. ;)
 
Last edited:
My bow thruster is 24 volts. To charge it, I have a 2 bank 12 volt 6 amp charger that is 120 VAC powered off my inverter, generator, or shore power. It's simple and works perfectly.

If you don't need to charge the house battery bank with it, why make it complicated.

16322669049154811890249160414251.jpg

Ted
 
My opinion?
Put it back to factory specs. It will be easier to trouble shoot for you and the next owner.
Start by replacing the dead alternator and work backwards through the system, replacing the dead parts as you go.
 
OldDan1943 said:
My opinion?
Put it back to factory specs. It will be easier to trouble shoot for you and the next owner.
Start by replacing the dead alternator and work backwards through the system, replacing the dead parts as you go.
Click to expand...
It's not a factory built boat so no factory specs

The dead part IS the alternator, twice now, loathed to go a 3rd.
 
Simi 60 said:
It's not a factory built boat so no factory specs

The dead part IS the alternator, twice now, loathed to go a 3rd.
Click to expand...

Look up the engine specs and see which alternator is standard then buy two.
While you are ordering, order a starter too. I assume you have a good supply of belts. LOL
(I have a spare alternator but still need the spare starter.)
Any idea how/why the alternators have failed?
Send it in for a rebuild and ask they 'why'.
 
Last edited:
OldDan1943 said:
Look up the engine specs and see which alternator is standard then buy two.
Click to expand...

So spend $1000 on alts to charge batteries when a $200 battery charge will do the same job?
Seems a bit wasteful of funds

While you are ordering, order a starter too. I assume you have a good supply of belts. LOL
(I have a spare alternator but still need the spare starter.)
Click to expand...
Already have


Any idea how/why the alternators have failed?
Click to expand...
As mentioned in the original post, charging the house battery bank

Send it in for a rebuild and ask they 'why'.
Click to expand...
Nah, sent it back and got my money back instead.
 
Simi 60 said:
I replaced it earlier this year with a continuous rated large frame 70 amp alternator but alas, it to has now died as it didn't like charging the house bank, apparently continuous rated doesn't mean what I thought it did

Question here is, if deciding to add a better charge source what would be better?
Spending $300 again on a dumb large frame alt but only have it doing starts and only doing its thing when engine is running?

Or spending a bit less on a dedicated smart charger like this Victron 24v 16amp which will do its thing 24/7?
Click to expand...


Do you mean the main engine alternator was your only charging source for the house bank?

I think I'd want a working alternator on the engine, at minimum for the start battery, no matter what else I put in place.

And then I'd probably also want a dedicated house bank charger. Something like that Victron, maybe, or perhaps Sterling offers something useful in your neck of the woods. Maybe an alternative for charging your windlass bank, too, if you look at 2-bank versions...

-Chris
 
"I replaced it earlier this year with a continuous rated large frame 70 amp alternator but alas, it to has now died as it didn't like charging the house bank, apparently continuous rated doesn't mean what I thought it did"

A better genuine continuous rated large frame alt is common on large trucks , $135 - $150 in USA.

If you have found a way to charge the house batts a tiny 24V car sized alt would be enough to recharge the engine start , if it can handle engine pumps and blowers that are engine powered.

If your engine has a PTO or you have room for double belts , I would guess the big 24V bus alts (DN 50) could be sourced from local rebuilders?

Here is one for a PTO, there are many other styles belt or HYD driven.
These put out real amps not BS amps.
https://www.ebay.com/itm/2840206498...1291&msclkid=da61eec6e9a11a8f70058f8dfd36c7eb
 
Last edited:
ranger42c said:
Do you mean the main engine alternator was your only charging source for the house bank?
Click to expand...
No
Main charge is 2500 watts of solar
Next is 7.5 kVA of Genset, rarely used
Then, as we like doing night passages we tried to use the alt to charge house when there was no sun.
FAIL

I think I'd want a working alternator on the engine, at minimum for the start battery, no matter what else I put in place.
Click to expand...
Yeah, not convinced
Alt only works when engine is running and has a 12 mths warranty
Smart charger works 24/7 and has a 5 year warranty.

And then I'd probably also want a dedicated house bank charger. Something like that Victron, maybe, or perhaps Sterling offers something useful in your neck of the woods. Maybe an alternative for charging your windlass bank, too, if you look at 2-bank versions...

-Chris
Click to expand...

We have a victron 24v 5000 va/120amp charge multiplus on house
Plus a midnite classic 150 mppt to do solar charge @ 96 amps
Just need something to keep two 12v linked as 24v tickled up.
 
Last edited:
Simi 60 said:
Yeah, not convinced
Alt only works when engine is running and has a 12 mths warranty
Smart charger works 24/7 and has a 5 year warranty.
Click to expand...


Not to worry. What I'd probably do doesn't have to be what you choose. :)

A smart charger only works until it doesn't, though, and that's why I'd be thinking of some sort of redundancy.

-Chris
 
I still think is worthwhile to determine why three alternator have failed.
 
OldDan1943 said:
I still think is worthwhile to determine why three alternator have failed.
Click to expand...

Simi 60 said:
Our engine does not require an alternator to run and the alternator died a a few years ago ago and we happily kept things going on a 24v 4amp port off of our inverter charger

I replaced it earlier this year with a continuous rated large frame 70 amp alternator but alas, it to has now died as it didn't like charging the house bank, apparently continuous rated doesn't mean what I thought it did

So, as the anchor windlass also runs off of the starts I suspect that we could be undercharging them using the 4amp alone even though we do see 27+ v on the battery monitor at times, if disconnecting the 4amp in batts drop back to 24+v

Question here is, if deciding to add a better charge source what would be better?
Spending $300 again on a dumb large frame alt but only have it doing starts and only doing its thing when engine is running?

Or spending a bit less on a dedicated smart charger like this Victron 24v 16amp which will do its thing 24/7?

Victron Blue Smart IP22 Charger 24/16 (1) | Shop AC Chargers Online

I tend to think option 2 is the better way to go as it's conditioning the battery but thoughts from others more knowledgeable appreciated.

Adding one of those $1000 plus smart balmar alts is never going to happen so forget that. ;)
Click to expand...

It's likely you are killing the alternators with oveheating if they are internally regulated. If you're not already using it a smart external regulator with alt temp sensing may be the solution. Balmar gear is on the spendy side. I had been planning on marinehowto's CMS alternators, I have twins, plus WakeSpeed smart regulators. But his store is down due to health problems. https://www.trawlerforum.com/forums/showthread.php?t=60069 As much as I appreciate Rod's contriubtions to the boating community in general and his unparalleled support of the gear he sells I need to get this upgrade done.

I'd much rather buy from and deal with Rod but I'm now looking at electromaax gear. Electromaax
 
I use GM CS-144, 12v, 140 amp, car alternators. In the US they're cheap and I've never had one fail. Parts are available online and you can buy a replacement internal regulator that's a single wire hookup. I use 8d Dyno batteries that last 8-10 years, so I guess the charging is ok. You can make them produce other voltages by changing the regulator or changing some parts in the regulator. I have a couple that produce 48v, 35 amps. Both my mains have 2 alternators, 12v & 48v for the house bank and inverter.
 
ranger42c said:
A smart charger only works until it doesn't, though, and that's why I'd be thinking of some sort of redundancy.

-Chris
Click to expand...

And an alternator only works untill I doesn't as well
What redundancy have you got after it fails?

The redundancy we have is the 4 amp wire off of the main inverter charger
 
Portage_Bay said:
It's likely you are killing the alternators with oveheating if they are internally regulated. If you're not already using it a smart external regulator with alt temp sensing may be the solution. Balmar gear is on the spendy side. I had been planning on marinehowto's CMS alternators, I have twins, plus WakeSpeed smart regulators. But his store is down due to health problems. https://www.trawlerforum.com/forums/showthread.php?t=60069 As much as I appreciate Rod's contriubtions to the boating community in general and his unparalleled support of the gear he sells I need to get this upgrade done.

I'd much rather buy from and deal with Rod but I'm now looking at electromaax gear. Electromaax
Click to expand...

Exactly right
And I know that is "A" solution
But like I said, I am not spending well over $1000 fixing something that doesn't really need fixing.

Existing 2500 watts of solar is more than capable of keeping house bank topped up
Then there is Genset if needed.
 
Last edited:
Lepke said:
I use GM CS-144, 12v, 140 amp, car alternators. In the US they're cheap and I've never had one fail.
Click to expand...

Unfortunately in Australia, best price I could get through a mate's account was $300 for a 24v 75 amp large frame Chinese clone.

They don't have that model anymore so the replacement they have is genuine Delco @ $700+

Not worth it to me for charging start batteries
 
Any thoughts on why you keep blowing alternators? Is this a matter if getting an external regulator to limit current, especially with your soon-to-be lithium setup?

This topic is a weakness for me, so following with interest.

Best success with whatever you decide.

Peter
 
Perhaps a misalignment between the alternator pulley and the driving pulley?
Doesn't take much to wear out the alternator bearing prematurely resulting canting the rotor causing touching and rubbing.
I have seen it happen on a Mercedes
 
OldDan1943 said:
Perhaps a misalignment between the alternator pulley and the driving pulley?
Doesn't take much to wear out the alternator bearing prematurely resulting canting the rotor causing touching and rubbing.
I have seen it happen on a Mercedes
Click to expand...

Nope

It's simply trying to charge too big a bank
 
mvweebles said:
Any thoughts on why you keep blowing alternators? Is this a matter if getting an external regulator to limit current, especially with your soon-to-be lithium setup?

This topic is a weakness for me, so following with interest.

Best success with whatever you decide.

Peter
Click to expand...

If I decided to use the alternator to charge house bank I would have to go the Wakefield or Balmar or similar
$850 for the reg plus similar for a decent alt
And then it only works when motoring
Some weeks that's as little as 4 hours

Solar on the other hand smashes in big amps for several hours a day, every day without burning fuel
For the cost of the big alt and regulator I could buy another 2kw of solar and really smash in the amps.

$200 24 volt charger gas been purchased to maintain starts
24/7 smart charging.
 
Simi 60 said:
And an alternator only works untill I doesn't as well
What redundancy have you got after it fails?
Click to expand...


Sure, but hopefully a charger and an alternator wouldn't both crap out at the same time.

I'm not particularly trying to convince you of anything.

-Chris
 
Last edited:
Based on your boat's electrical set-up, I vote for option #2 (dedicated smart charger for the start bank). It has too many advantages to not go with it.

I know that the battery bank discussed here isn't lifepo4 but here's an interesting video.
 
Simi 60 said:
880ah @ 24v of AGM
Soon to be
840ah @ 24v of LFP
Click to expand...

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? I personally went from Balmar to Wakespeed (WS500) and LOVE it!!! In fact, I just ordered another one for my other engine so I can have both alt's charging the house and the starts would get their charge (topped off starts in 10-15 mins)...
UGH!!! :( As I was going to paste in the link to Wakespeed I just realized the one I was going to show you is only a 12v version (WS100)... So if you did want to go this route the WS500 would be the one you would need for your 24v system...

Well, either way, STILL highly recommend them! EASY setup, no more stupid magnetic tip pens for programming and HOPING you got the right "tap" in the right sequence... ;)

Wakespeed Products

Off Grid also includes software to really dial in your performance needs... :)
https://www.offgridsoftwaresolutions.com/product/ws500-smart-regulator/
 
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.

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.

Do you have enough battery storage to enable a night's cruising before solar recharges the house bank the next morning?

Yes? Then just use the cheap vac or dcdc charger for the start bank. No, you need alt charging? Just charge the start bank with the alt and the LFP house bank from there. You will need a surge bank anyway to prevent the alt from self destructing when the house bank is full and cannot receive charge. A thermal cutout between the two banks could be used to prevent alt over temp ie break the parallel connection if the alt overheats.
 
Last edited:
You must log in or register to reply here.

Similar threads

Dougcole
Lithium House bank/FLA start/Twins
Replies
8
Views
1K
SteveK
SteveK
REO
multiple charging source problem
2
Replies
32
Views
2K
luna
L
H
House battery system too low to charge
Replies
13
Views
2K
hickleyboy
H
markpj23
Mastervolt Charger Issue
Replies
7
Views
834
markpj23
markpj23
Action
Charging batteries and 12 V system underway
Replies
24
Views
2K
ranger58sb
ranger58sb

Latest posts

Back
Top Bottom