Smoke from the alternator! Fried?

[NPMR]

Arrived at the boat yesterday having not seen it for 2 weeks and found that I had not switched the batteries off (or shut the engine water!!!)

Result, completely flat new 80Ah battery. Started the engine (No 2 battery) and switched back to No 1 battery to put some charge in it - we have Sterling battery manager etc.

28 amps were pulled and after about 3 minutes, there was smoke and 'hot smells' from engine bay. Dropped revs, switched back to No 2 battery and all seemed to cool down.

Later same day ran engine and again 27 amps were pulled and smoke soon reappeared!

Terminal damage or a lucky escape?

PS Took the dead battery home and this morning after about 15 hours on 'Battery charger' it won't take any more charge. Is this likely? It's only a car cattery 'trickle charger' type thing from Halfords?

 

[[2574]]

Depends where the smoke is coming from. It sounds as thought the alternator is still producing power ok so no reason to think it's dead. The smoke is worrying though - could be undersized cabling? Watch out that the whole lot doesn't catch fire; if you're feeling out of your depth I'd get a teccy to look at it - you don't need a fire on board!

It's possible that the Halfords charger has largely recharged the battery (they're generally 4A chargers so 15hrs would theoretically be 60AH).

rob

 

[steve6367]

I had the Sterling alternator regulator on my last boat (with 1GM) and although never got to the point of smoke I did have problems with the alternator getting very hot and smelling hot when the house bank was heavily discharged. After speaking to Sterling I fitted a switch in the "boost" circuit so that I could control when it was used. This seemed to solve the problem. The slightly more expensive version of their alternator regulator has alternator temperature sensing to avoid this problem.

Not sure if this is what is happening to you as smoke sound more serious, but worth checking.

 

[mikemonty]

A burning rubber "hot smell" may just be a heavily loaded pulley belt.
A burning insulation "hot smell" is probably worse.

 

[William_H]

The alternator has possibly not really worked hard for many years during which time all sorts of crud which could produce lots of smoke when it got hot. Of course it might also have been the belt slipping making a bit of smoke. Or as suggested the wiring.
If you were really concerned about the alternator they are not that hard to dismantle to check for burnt wir in the coils but I really doubt it.
good lcuk olewill

 

[VicS]

[ QUOTE ]
found that I had not switched the batteries off
Result, completely flat new 80Ah battery.

[/ QUOTE ]

This needs investigating , unless you left lights or equipment switched on the battery should still have been OK. You don't switch the battery off if you leave your car for a couple of weeks (nor can you in any car i know of) yet still it is OK when you return. In this respect the boat is no different.

As far as charging the battery with a small charger goes, unless it is a very small one designed for a maintenance charge only, charge until the volts have risen to about 14.4 ish and been at that for about an hour . Then let it rest for 12 hours and check the battery volts. If its around 12.7 or 12.8 its fully charged, if its only 12.2 its only about half charged if is only about 11.7 it is still flat . if it is not sealed and you have a hydrometer check the electrolyte with that .