Charging a 6v motorbike battery

[beerbeerbeerbeerbeer]

I need to charge a 6v bike battery. 

 

I have no 240v on the boat, so I can’t simply plug in my standard charger for the battery. 

I only have access to 12v. 

 

Is there a safe and simple way to trickle charge a single 6v battery from a 12v set up?

 

or does anyone know where I can get a battery charger with a 12v plug? 

 

Thanks. 

 

[Robbo]

If you have two 6v batteries just add them in series.

 

Or a redneck way : https://www.youtube.com/watch?v=UVkv_oVtG3w

 

[Alan de Enfield]

30 minutes ago, Goliath said:

I need to charge a 6v bike battery. 

 

I have no 240v on the boat, so I can’t simply plug in my standard charger for the battery. 

I only have access to 12v. 

 

Is there a safe and simple way to trickle charge a single 6v battery from a 12v set up?

 

or does anyone know where I can get a battery charger with a 12v plug? 

 

Thanks. 

 

There are a variety of 12 v ' step-down' on ebay - try one of those.

 

Or here :

https://www.amazon.co.uk/Yeeco-Converter-Regulator-Transformer-Automotive/dp/B01KFE0BK4

 

 

[Nickhlx]

To charge a 6V battery at say 1 amp, simply put a 6 volt 6 watt filament bulb in series with it - the bulb will pass 1 amp at six volts and slightly more if voltage slightly higher, and the battery will get the same current passing through it, thereby charging it

 

Nick

[beerbeerbeerbeerbeer]

Thanks for the ideas. 

I’ll try the 6v 6w bulb method. 

 

[stegra]

I think I'd favour a small inverter and a 6v mains battery charger.

[Tony Brooks]

I think for the bulb trick to work you will need the 12V battery on charge. The bulb and battery form a voltage divider so a fully charged 12V bate try would produce a charging voltage of about 6.3 ish but if on charge more like 7 + volts.

 

[beerbeerbeerbeerbeer]

59 minutes ago, Tony Brooks said:

I think for the bulb trick to work you will need the 12V battery on charge. The bulb and battery form a voltage divider so a fully charged 12V bate try would produce a charging voltage of about 6.3 ish but if on charge more like 7 + volts.

 

For my 12v battery to be on charge I would simply run my engine. 

Would that be safe? (There is a fuse already attached to the battery. )

 

 

[WotEver]

21 minutes ago, Goliath said:

For my 12v battery to be on charge I would simply run my engine. 

Would that be safe? (There is a fuse already attached to the battery. )

Yes, perfectly safe.