Jump start

[Graham Honnor]

My battery has just about given up but I'm reluctant to buy one this year as I'm not even sure that 
I'll be getting out in it but I need to move it around at home.
Is there a safe way of jump starting it off a 12 volt battery as it is only 6 volts please?
I'm sure that once she starts it will run okay as it's not completely dead but I'd rather drive it around
than try to push it.
Many thanks
Graham.

[Parazine]

You will need another 6V battery connected in series to jump from 12V.

Better to buy a 6V charger from eBay.

[Graham Honnor]

Thanks for the reply.
I've had her on an Aldi trickle charger all winter but she won't hold a charge 
for very long now.
I also tried given it a bit of a boost by putting her on a normal 6 volt charger 
for a couple of days but still no better.
Looks like it's a push around job then.
Thank you.

[Chris KC]

Starting handle? You don't need a lot of juice in the battery to run the ignition circuit.

[Peter Clayton]

I ran my RP on my 9 volt drill battery when my  battery died. hand start of course .

[Robert Leigh]

When I was a poverty stricken apprentice I used to handle start using a 4.5 volt hand lamp battery, and with the hand throttle set to a rather fast tickover it would continue running on the dynamo. I did this for 3 or 4 weeks until I had saved enough to buy a usable battery from a scrap yard.

[Bob Culver]

The dynamo should not be run without a battery, certainly not for long or at revs as the sytem voltage rises and may burn out the field coil as well as bulbs.
Odd though it seems and contrary to usual eletrical practice, connecting the F and D wire at the dynamo and both securely to earth stops  the dyanmo generating. Provided not a DEL 4 pole dynamo with the internal resistor intact, disconnecting the F wire at the output form the dyn body will also disrupt.
On the later RP and later cars,  assuming wiring is exactly original and not DEL dynamo, selecting Summer and removing the charging fuse will disable the dyanmo.

[Colin Wilks]

If you must use the starter I would isolate the 6v live from the starter, effectively taking the starter out of the 6v system altogether, but maintaining the 6v live continuity, and use the 12v leads directly onto the starter. I do not think you will do any permanent damage to it as a one off, but the starter will fairly kick.

[Nick Turley]

Why stuggle - treat yourself to a battery.
You are risking damaging the dynamo without.
We are all going to be driving around soon, hopefully.
The 80 amp hour Exide lasts for eight years if you look after it.
Cost £7.50 per year.
Personally I use a battery conditioner/charger (Optimate 5).
I have tried several others (a mixed bunch!) including CTEK and found the Optimate 5 gives good reliable performance on 6 volt systems.
My Austin Seven batteries had previously been lasting five years on average now they last eight on average.
Hope this is helpful.

[Tony Griffiths]

There's a slim chance that you might be able to bring the battery back to life.  A common cause of failure is a battery kept at less than 80% of full charge 9storage, short journeys, etc) the electrolyte concentrates at the bottom of the plates and this is where an Optimate or similar helps to prolong battery life, it keeps them topped up. 
Try shaking the battery or - taking precautions - tipping it over a few times. I remember decades ago draining the acid out of a dead MGB 6-volt battery, washing it our with distilled water and putting the acid back. After a charge, the battery worked.