Charging battery from outboard

[ShinyShoe]

The rectifier BTW is ~£77, kit is ~£133
That doesn't include any charge controller.
From what I can see from googling ( https://www.tohatsuoutboardparts.com...0221054-1).pdf ) you already have the alternator. You probably have a white and yellow wire that terminate at loose terminals. Alternator spec seems hard to find but looks like it would be 60-80W. About 5amps.

If you ran that into this: New 150-250 CC Engine Motor Voltage Regulator Rectifier 4Pin Female Plug | eBay

Pin in/outs:
Yellow - Connect to the yellow wire from the alternator
Red - Connect to 12V +ve of battery via a 3Amp fuse
Pink - Connect to the white wire from the alternator
Green - Earth Connect to engine body, and to 12V -ve of battery

Before connecting to a battery I'd suggest running and checking the voltage with a meter - expect 14.4V or thereabouts.

Secure the rectifier to something big and "metally" that will dissipate heat.

That unit is a rectifier (converts AC to DC and a regulator converts varying voltage to c12V. ) It doesn't manage the battery charging. There is a possibility you could over charge battery if you don't have any drain on the current ever running such as lights or radio etc. If thats a possibility you want a charge controller like you put on a solar panel too. BUT assuming you will have some drain running you will probably be fine, especially as you wont be motoring for 72 hours solid.

If I'm remembering right you said you have 34Ah of battery on board. That would discharge down to about 14Ah and then be 'dead'. Recharging that 20Ah drop will take about 7 hours with no draws on current. But assuming you head out with full batteries and have engine running while the electrics are on chances are you aren't draining anything... its the drifting that will discharge you. You'd need to know what your current draw is in "drift mode" and how long you drift vs motor. To be honest you need the drift mode current draw no matter what solution you adopt or its all guess work...

[ShinyShoe]

Originally Posted by Poly

Eh?

The actual pack Kaman links to is not a 21Ah jobby but a Li Battery. Type of thing you can charge your phone from 8000 times from an inbuilt USB port, but as this is the super powered model you can also start a car and fly to the moon. But for some reason, that I assume is technical rather than bad design, they don't let you charge while discharging, unlike with a Lead Acid where you can feed the battery from an alternator and either draw more than you are putting in or less and charge the battery up more... ...the Li power packs insist on switching between discharge and charge mode. (Or all the ones I looked at when trying to find a battery backup solution for a RasPi did)

[jeffstevens763@g]

Originally Posted by pilotwillie

Jeff, totally agree with all you've said.

Just not with your poor comment of Clyde Outboards (although you may have your reasons for this and that's your business) but was hoping it came from the simple misunderstanding I highlighted. I see Kaman has cleared this up also. IMO they're all 'brand new' that work there, but that would be for another thread !

I personally would also rather be charging up something electrical from a mechanical source giving good redundancy.

Total misunderstanding willie I worked years with scotch lads never heard the term brand new down hear it's no expearence I have apologised thanks for pointing it out no offence intended.

Cheers

[jeffstevens763@g]

Shiny

The kit I got for my Suzuki £106 is a rectifier & regulator assembly in one hope that helps

Cheers

[pilotwillie]

Originally Posted by jeffstevens763@g

total misunderstanding willie i worked years with scots lads never heard the term brand new down hear it's no expearence i have apologised thanks for pointing it out no offence intended.



Cheers

👍🏻👍🏻.

[9D280]

Originally Posted by ShinyShoe

Well I spent half my life in Glasgae

That's a festival..... I think you meant "Glesga"


I only read this thread now, so this comment might be too late - I got a used Suzuki Outboard Rectifier / regulator for something like £20. (replaced the "rectifier only" that toasted my first battery on the Clamshell). Granted I had a wiring diagram for both the engine and the new electrical bit to hand!

With my limited SIB experience, My thoughts would be that having something else to fill the boat usually just results in a trip hazard or pain as it meets you on the way past when you hit an unexpected wave!

[Poly]

Originally Posted by 9D280

With my limited SIB experience, My thoughts would be that having something else to fill the boat usually just results in a trip hazard or pain as it meets you on the way past when you hit an unexpected wave!

Kaman is a pro though with all his kit tied down and neatly stowed for reasonably long trips.

Originally Posted by ShinyShoe

Before connecting to a battery I'd suggest running and checking the voltage with a meter - expect 14.4V or thereabouts.

That could be an expensive mistake. Regulators tend to go pop with no load attached.

That unit is a rectifier (converts AC to DC and a regulator converts varying voltage to c12V. ) It doesn't manage the battery charging. There is a possibility you could over charge battery if you don't have any drain on the current ever running such as lights or radio etc. If thats a possibility you want a charge controller like you put on a solar panel too.

? There is no clever battery charging electrickerry circuits in a normal outboard arrangement, you don't boil the battery because the voltage is properly regulated.

[kaman]

Cheers guys for all of your input.
I'm still not decided how to address my electrical dilemmas but I will do in the new year once my fixed DSC radio is installed and ready for action.
I will have a chat with my local dealer whom I bought my Tohatsu outboard from before I make up my mind.
He's also "brand new" :sly:
Excellent input on here sure has given me a good starting block for next year.:thumbup:

[ShinyShoe]

I think we may need to set Myth Busters away on this one...

Myth One: An Expensive Mistake - its a £5 rectifier

Now apparently according to the science of Poly it can't boil your battery because the voltage is regulated... ...but what about the current? Boiling your battery is affected by both from my understanding.

But if thats the case the regulator must be capable of not putting any juice into a fully charged battery to avoid boiling it. On that basis the regulator must be able to cope with no battery connected?

But yes if running for any length of time or at any more than tickover or without the heatsink attached to plenty of heat disepating surface a load to take the power away from the heatsink would be good, that could be a 25W, 12V car side light bulb. If its not wired correctly you blow the bulb (£1) not the battery £30-100

[Poly]

Originally Posted by ShinyShoe

I think we may need to set Myth Busters away on this one...

Myth One: An Expensive Mistake - its a £5 rectifier

Now apparently according to the science of Poly it can't boil your battery because the voltage is regulated... ...but what about the current? Boiling your battery is affected by both from my understanding.

But if thats the case the regulator must be capable of not putting any juice into a fully charged battery to avoid boiling it. On that basis the regulator must be able to cope with no battery connected?

No. The "feedback" from the battery to the alternator is the voltage. No volts (disconnected battery) "tells" the alternator to supply more power which it does, but still gets no volt feedback and the process runs away eventually going pop (and if you are lucky only the regulator gets fried). In contrast a fully charged battery sends back a "good" voltage signal which reduces the current output.

I don't know how you'd get high current into a working battery without pushing the voltage above the normal charging range?

When you ruin the cheap rectifier you also risk damaging other stuff...

[kaman]

I think the technical discussions on here have sealed the deal for me chaps.
The rectifier / regulator route sounds I bit too technical (for me).
I'd be bricking it in case my handy work resulted in blowng up my battery, frying the electrics or knackering my outboard.
I think a deep cycle leisure battery will be the order of the day.
I'll make a little storage compartment in the bow box and run a cable to my vhf.
I can charge it in situ when I get home without having to remove it.
Keeping it very simple........
Another point to consider is my outboard is on and off the transom and in and out of my car boot when under tow.
Also adding a cable to the outboard to charge the battery slightly complicates removal / installation - not a major issue tho.
A mechanical failure of the outboard is going to result in a trip being cut short as my auxiliary won't be able to charge up my battery.
I'll carry enough juice in my battery assortment to last my 3-4 day trip or scale back if it's only a day trip.
When I say farewell to the Sib I'll be sure to buy a set up that is ready sorted with capability to charge a battery tho

[Poly]

Kaman, if you take the engine off each time I think you are probably making the best decision. Might be worth thinking about how 9d280 charged his from vehicle electrics when towing - might just extend your range?

[jeffstevens763@g]

Originally Posted by kaman

I think the technical discussions on here have sealed the deal for me chaps.
The rectifier / regulator route sounds I bit too technical (for me).
I'd be bricking it in case my handy work resulted in blowng up my battery, frying the electrics or knackering my outboard.
I think a deep cycle leisure battery will be the order of the day.
I'll make a little storage compartment in the bow box and run a cable to my vhf.
I can charge it in situ when I get home without having to remove it.
Keeping it very simple........
Another point to consider is my outboard is on and off the transom and in and out of my car boot when under tow.
Also adding a cable to the outboard to charge the battery slightly complicates removal / installation - not a major issue tho.
A mechanical failure of the outboard is going to result in a trip being cut short as my auxiliary won't be able to charge up my battery.
I'll carry enough juice in my battery assortment to last my 3-4 day trip or scale back if it's only a day trip.
When I say farewell to the Sib I'll be sure to buy a set up that is ready sorted with capability to charge a battery tho

Hi Kaman

I know it seems a bit technical but don't over think the fitting of the charging kit it is so easy my missus could do it, if you pm me your address I will copy the fitting instructions that came with my kit for you to have a gander at before you make your final decision.

Cheers

[kaman]

Cheers Jeff.
PM sent.

[9D280]

Originally Posted by Poly

Kaman, if you take the engine off each time I think you are probably making the best decision. Might be worth thinking about how 9d280 charged his from vehicle electrics when towing - might just extend your range?

Simples. (even more simple if you ghave an old school "N&S" pair of sockets......

I have a 13 pin socket, so on the trailer I put a breakout box with a 2 pin Bulgin Buccaneer socket (submersion proof). Wired the socket to the Caravan battery charge pins and then ran a lead to the console using another Buccaneer plug / socket, esentially treating the boat battery like a caravan battery. I just remove the lead before launch in the way you would the lighting board.

If you have the old twin 7 pin sockets it's even easier as your charging circuit is o nthe "white lid" plug, so it's literally a case of 23S plug one end, and something suitable to connect to the boat at the other.

If, however, you have a single 7 pin you'll need to retro - fit a white one alongside. (if you need, I have a spare split charge relay lying in a box in my garage - could probably hand it to you if you are in the Glasgow area!)

No worries about fuses as that should be done by the car.