Battery Charging - Yamaha 2-stroke

[Ronald_M]

Hi, all.

Does anyone know if it is possible to retro-fit some kind of battery-charging system to a Yamaha 4HP 2-stroke outboard?
I seem to recall that this may have been an option on new engines.

Cheers,

Ron.

 

[Talbot]

even if you did, the useable power would be so low as to be virtually useless, and it would degrade propulsion power at the same time. without details of what you want to do with the power, and what sort of boat, it is impossible to give you alternatives.

 

[Ronald_M]

My new trailer-sailer is fitted with an 85ah battery for powering log/depth, nav-lights and a couple of LED cabin lamps. It will be feasable to take the battery home for charging or to do so at the yard where the boat is based. It would, however, be convenient to be able to charge whilst cruising.

Ron

 

[Talbot]

Recommend that you change your nav lights to leds, then there are two simple choices, dependent on where you cruise to, and where you stay once you have arrived. If a marina, use a 240v connection and a battery charger, if anchor or otherwise, consider the use of a roll-up solar panel,

 

[moondancer]

If there is a kit for that model it is likely to be around 50 quid. The Mercury / Mariner 4HP s stroke gives out about 2 amps which is fine for topping up if you just want to run a sounder and a log. The solar panel suggestion is a good one to keep the battery topped up all the time.

 

[simonfraser]

prob is you are unlikely to be running the outboard for long enough to put any usefull charge into the battery

 

[VicS]

If your engine has a power output (AC) for nav lights then all that is required is a rectifier. It would be probably possible to use a suitably rated bridge rectifier from Maplin or similar but a charging lead, incorporating a rectifier, would almost certainly be available as an (expensive) accessory.

If you do not have such an output then the engine would have to be fitted with a coil within the flywheel. That may or may not be feasible. In either case it'll be even more expensive.

You have not told us exactly what engine it is so it is unlikely that anyone can give more detailed advice.

As others have said the amount of power you would get is very small, so small that unless you are running at high revs for long periods it is hardly worth the bother and expense.

A fixed solar panel of 5 or 10 watts will be a better bet. Mine is 5 watts but if you have the space 10 watts would be better. With an 85Ah battery you would not need a regulator with a 5watt panel but it would be advisable with a 10 watt panel.

A roll-away panel that is not connected permanently would have to be larger.

 

[dave_gibsea]

Why not get one of those £45 2-stroke generators as sold by B&Q?

 

[Ronald_M]

Thanks for all the advice. I'll probably try to keep it as simple as possible - a small 10 watt solar panel might be the best solution.

Ron.

 

[AngusMcDoon]

I don't know what you can get out of your Yam, but it is possible to run a small boat successfully on a low electrical power budget. I have a Yam outboard which produces 6 Amps, a 30W solar panel and shore power when available. On that I run log, depth, windy, GPS, autopilot, VHF, chart plotter (but not constantly), a Waeco compressor coolbox, LED nav lights, CD player, LED anchor light. Internal lights are used sparingly - I use oil lamps if away from mains.

Electrical stinginess helps, as does knowing what each item takes. I've never run out of Coulombs so far in 5 years of Ampere miserliness.

 

[graham]

Many years ago I retrofitted a charging rectifier to an 8 hp Yamaha 2 stroke.Unfortunately no longer have the details of where I got it from. It was sufficient to cope with normal nav lights cabin lights etc.The engine allreadyhad a "lighting coil"fitted .Check if your motor has ,if so it should be relatively simple to fit a rectifier .

My Suzuki 4 hp 4 stroke has a charging coil /rectifier fitted which gives me about 4 amps charge and seems to have no apparent effect on the power of the engine. I think Talbot is confusing belt driven alternators with small outboard lighting/charging coils.

I am frugal with lights etc but with the power output from the Suzuki I never need to use a battery charger.