Alternator belt Slippage

[Q Xopa]

Originally Posted by john61ct

Bulk (CC) stage it's the battery that controls voltage anyway, it's the Absorb setpoint that gets held by the VR possibly for hours once the CV setpoint is reached.

OP does not even know if VR is adjustable, nor if it drops output to a lower Float voltage.

Voltage setpoint needs to match the needs of the battery anyway, if there's no DCDC charger in between.

Yes if the Voltage set point could be and was lowered to below the manufacturers recommendation than that would be undercharging the battery which would mean a shorter life due being in a PSOC (pattial state of charge) condition too much, which isnt good for them and leads to sulphidation etc.

The DCDC charger suggestion may work, However it is not addressing the source of the issue. It is akin to driving down a hill keeping your foot on the gas but also stepping on the brakes to slow down. Different ways to skin a cat but not how I would approach this.

Why not just take your foot off the gas?

I see a lot of very poor belt drive setups. Alignment, pulley incorrect, condition, good belts etc. This is where I would start. While the belt is off check all the bearings for pump and alternator. Get things to how they should be first.

If all this looks ok, Jims suggestion of some Belt grip spray is not so silly.

Then start looking at upgrading- like a nice external regulator, etc set up. Of course this option is not cheap.

[Fiftybucks]

Found this interesting tidbit on squeal:

V belt squeal. Spray water on the squealing belt. If the sound worsens you have a tension issue. If the sound goes away you have an alignment issue.

Quote is from 2016 issue of Passage Maker Magazine.

[a64pilot]

It’s sometimes a pain to do but if you can mount an idler pulley that causes the belt to wrap around the alternator pulley more that can greatly increase the friction and therefor the power transmission of the belt.
Belt dressing works, it’s usually temporary and has to be reapplied every so often but it works.
I just went to a serpentine belt, the kits are sort of hokey as a good serpentine system should have an idler that applies tension, then the belt never has to be adjusted, and it maintains correct tension even on a hot engine, as an engine gets hot, the diameter of the pulleys increases slightly, and tightens the belt further.

[akopac]

GATES GREEN STRIPE BELT

[Kokanee]

My 115A alternator is driven by a standard v-belt and I've yet to have any belt slippage problems.

If yours has been slipping for a while, the pulley could be worn/glazed or deformed from the heat buildup.

[Fiftybucks]

akopac - gates green stripe is the best of the gates belts and i plan on trying one but also the Dayco Top Cog... 15405. Westerbeke recommends the Dayco Top Cog. I will replace with slightly shorter belt than the one on it. I will try both to see which belt eliminates the squeal. I will also take a close look at the pulley surfaces for glazing there. I will report back but it may be a few weeks..

[model 10]

I had to put the spare alternator on this year (115a Delco Marine.) I thought the V belt groove was the same but it was even more narrow than the 1/2" Balmar pulley. Took the pulley to the local machine shop and he re-cut the groove, no big deal. Even with the wider Green Stripe belt, it squeals like crazy until I hose it down with belt dressing. I hate the stuff, it slings off and I can't find a solvent that cuts it.

I like the idea of an idler.

[DeepFrz]

Originally Posted by Ecos

I had to put the spare alternator on this year (115a Delco Marine.) I thought the V belt groove was the same but it was even more narrow than the 1/2" Balmar pulley. Took the pulley to the local machine shop and he re-cut the groove, no big deal. Even with the wider Green Stripe belt, it squeals like crazy until I hose it down with belt dressing. I hate the stuff, it slings off and I can't find a solvent that cuts it.

I like the idea of an idler.

Try rubbing a bar of soap on the sides of the belt. Just a little.

[wingssail]

Originally Posted by Ecos

I had to put the spare alternator on this year (115a Delco Marine.) I thought the V belt groove was the same but it was even more narrow than the 1/2" Balmar pulley. Took the pulley to the local machine shop and he re-cut the groove, no big deal. Even with the wider Green Stripe belt, it squeals like crazy until I hose it down with belt dressing. I hate the stuff, it slings off and I can't find a solvent that cuts it.

I like the idea of an idler.

I really think you need to very closely examine all the pulleys and their v's and especially the alignment and the tension you put on the belt. This should not be brain surgery.

We have, like I said, 110amp alt on a single belt, with a 6.6:1 pully diameter so that alternator is spinning like crazy, we're getting over 100amps at start up, and there is no squealing, no shredding of belts, and little powdered rubber around the front of the engine. AND we used whatever cheapo belt we got at an auto shop in Martinique which looked about right, for five years, and we just changed to one of the spares a few months ago.

If I can do it with my loose as a goose mechanical approach, anyone can. Check it all again!

[lateral]

Originally Posted by wingssail

I really think you need to very closely examine all the pulleys and their v's and especially the alignment and the tension you put on the belt. This should not be brain surgery.

We have, like I said, 110amp alt on a single belt, with a 6.6:1 pully diameter so that alternator is spinning like crazy, we're getting over 100amps at start up, and there is no squealing, no shredding of belts, and little powdered rubber around the front of the engine. AND we used whatever cheapo belt we got at an auto shop in Martinique which looked about right, for five years, and we just changed to one of the spares a few months ago.

If I can do it with my loose as a goose mechanical approach, anyone can. Check it all again!

Ditto- except for the ratio with <6.6:1.
Does 100+A just over idle.
Eats a green stripe belt every 100+ hrs. ($10)
Way cheaper than serpentine kit and not and option anyway with
compressor for refrig.

[wingssail]

Originally Posted by lateral

Ditto- except for the ratio with <6.6:1.
Does 100+A just over idle.
Eats a green stripe belt every 100+ hrs. ($10)
Way cheaper than serpentine kit and not and option anyway with
compressor for refrig.

Sorry, my mistake, a 5.25" crank pully (circ= 16.49) and a 2" (circ = 6.28) is 2.6 to 1.

And, the 100A is as soon as our reg finishes with ramp up stage, engine is at 2000rpm, alt output is 100A or more, tapering off quickly.

Eats shitty belt in 5 years.

No need for serpentine

[j.g.evans]

Been there with a 100A Balmar. Belts broke frequently. Balmar sent me a larger sheave and I have had the same belt for almost 10,000 miles.

[FuzzyFeat]

I am assuming that your engine is a Yanmar. If your alternator is being driven by a single belt that also drives the FW pump i came up with a solution when i experienced that same problem. It was published in Good Old Boat magazine some years back. Simply put: it involves an additional sheave on the PTO and reversing the drive sheave on the FW pump. You now have a single belt driving the alternator from the original PTO and a separate belt driving the FW pump from the added sheave. image attached. If you need to know more, let me know.

[belizesailor]

Originally Posted by wsmurdoch

...and if you spray the belt and the noise does not go away, it may not be the belt that is squealing. ...something else?



Like starting fluid (ether), belt dressing is useful for diagnosing problems.

A similiar trick I learned from a pro mechanic friend when belt dressing was not available is to spray it w WD40 or similiar. If its belt squeak then it will go away temporarily.

[sailorladd]

Yes, never isolate the running alternator from it's battery source, you will blow diodes...happened to me in Fiji...an expensive mistake.

I am not sure about your battery configuration, but I only had 2 batteries on my boat and would NEVER charge them simultaneously , buy always separately...consider trying that rather than charging all at one time, if indeed that is what you are doing... way too much load on the alternator and hence the squealing I am assuming...you might also examine the belt and pulleys for oily surface?? they should all be squeaky clean (pardon the pun)