Charging Batteries while in neutral

[AnegadaDave]

While racing in long events I need to charge the batteries with the engine. I have a Volvo D1-30 sail drive with folding propeller.

Can I sail and charge the engine in neutral without damaging the transmission? The manual says set the shaft in reverse while sailing to lock it.

Thanks!

AnegadaDave

[Captsteve53]

Thats Strange here's the page from the Yanmar operation manual Manuals SD50 / SD50-4T

NOTICE: When sailing, set the remote
control lever in neutral. Not doing so WILL
introduce slippage and void your warranty.

And from the SD20:

NOTICE: When sailing, set the remote
control lever in neutral. Not doing so WILL
introduce slippage and void your warranty

If running the engine in Neutral then the sail drive unit is dis-engaged so cant see why you have any issues or makes any difference,

Cheers Steve

[Captsteve53]

Whoops! Sorry thought it was Yanmar

[Captsteve53]

As you say following Quoted from my VOLVO manual (never bothered to look prior)As have always sailed and charged Batteries (obviously in NEUTRAL)

When sailing the control lever should be in the reverse position if a folding propeller is used and in neutral position if a fixed propeller is used.

The above just dosent make any sense in so many ways

1) Our Engine will not even start in gear it must be in Nuetral

2) Normally in Races the drive shaft or linkage is sealed in Nuetral

3) It states if fixed prop leave in NEUTRAL and if so there fore the drive shaft/sail drive is rotating

I can understand the reverse gear situation to help fold the prop and there fore reduce drag/noise (depending which school of thought you belong to!)- Dont want to go there-Again!!,

Cheers Steve

[AnegadaDave]

Thanks for the comments. I checked the Volvo manual and confirm it states " put in reverse with folding prop while sailing" .

But obviously going to be in neutral while engine charging while sailing. It doesn't cover that.

No other choice really....thanks again.

Dave

[CarstenWL]

... would be amazed if your alternator will put out any decent current at neutral RPM.

Also check if the races you sail actually allow this (engine on).

Regards,

Carsten

[Meacenas]

I would think that the rpms at idle and in neutral would be too low to do any charging. You would have to check that with a multi-meter. You may have to bump up the throttle to show any charge. Then there is the question a previous poster asked...is it allowed during a race?

[Lionelsole]

Originally Posted by CarstenWL

... would be amazed if your alternator will put out any decent current at neutral RPM.

Also check if the races you sail actually allow this (engine on).

Regards,

Carsten

Neutral, not idle. Volvo engines can be revved as required in neutral.

I have done just this and don't believe an occasional use will damage transmission. I'm told, however, that it is a perfect recipe for glazing the engine bores, so always give a few minutes under significant power to get it up to temperature. Obviously not an option when racing.

[AnegadaDave]

Yes my gear shift lever does have the disengage button to rev engine in neutral. The Lake Erie Solo race is 315 miles so need to charge a bunch to build amps for the auto helm. Totally encouraged in the rules.

[wcapital]

How about......add solar panels (and a wind generator - if night time or more charging capacity needed)? Alternators are inefficient - generally never charge battery completely), and running engines for extended periods without much load isn't so good for them....

[Jeffrey Oc]

The motor will definitely charge in neutral and you can increase the rpm also. Some will
say it's not good for the engine, but sometimes if you want charged batteries you don't have a lot of choice . We are just adding more solar to reduce engine hours. Here's hoping.

[DEAN2140]

I have chartered in many places and the standard advice is to run the engine @ 1200-1500 RPM.

[a64pilot]

It will work fine, you will not hurt anything.
However as a daily routine over long periods like out cruising, it's best not to run the engine in neutral for extended times as you can get bore glazing. However once in a while won't hurt anything, trucks used to idle overnight for years, but would run on the road the next day, if they just idled overnight and were turned off during the day, they would glaze.
Bore glazing is where combustion byproducts do not burn off and over time form a glaze on the cylinder walls filling in the cross hatching who's purpose is to hold a film of oil for the piston and rings to be lubricated.

[hellosailor]

Dave-
You might want to contact Volvo directly, and if you have a trusted Volvo mechanic, ask them as well. The recommendation to put the engine in reverse MIGHT have to do with whether the prop can turn the shaft, versus whether the shaft and transmission rely on the engine being on, in order to run an internal fluid pump for lubrication and cooling. In that case this is critical and it does vary between different transmissions.
Or, the transmission may not care, and the recommendation may just be in order to keep the prop blades folded, streamlined for less drag. In which case putting a couple of rubber bands over the folded blades before the race starts would do just as well. (They'd break off it you needed to use the prop.)
But I'd submit that this is nothing to guess at.

As to charging at idle speeds...it is indeed possible. I've done it, by having a custom alternator pulley made up that matched "idle" engine rpms to good alternator shaft rpms, so a particular alternator that we'd chosen was able to make something like 50% output AT IDLE while not being over-run at "battle speed".

There are some alternators that don't really wake up until 2500rpm, while other are putting out good power at just 1000. And some that will burn out if they run at 10,000 rpm for an hour, while others can exceed 15,000 rpm all day without a problem. (These are alternator shaft rpm's, not engine rpm's.)

The trick is, determine the ratio of engine speed at idle to engine speed at max. That may be 1:4 or 1:5, say 800rpm to 3000 rpm. Now find an alternator with the same range (1:4 or 1:5, etc.) and choose or machine the alternator pulley so it keeps the alternator in that range. The alternator pulley on your boat was chosen because it was a cheap stock size--designed for a CAR in all likelihood.

A properly spec'd pulley can cut your charging time IN HALF, especially if you charge during low speed runs. Might cost $100, but it is easy to burn that in fuel, too.

[Captdd]

Ahoy AG,

Just put it in gear to charge!
This will surely assist in the race outcome as well!

Cheers