Charging from the cigarette lighter?

[DomRC]

Had my first taste of racing outdoors on the weekend and was wondering if anybody had ever modified the 12v input on their charger to charge from the lighter socket in their car? (mine's a bantam bc6)

Are there adaptors for that? Will save needing to buy a generator or battery....

[Southwell]

Unless you have a huge battery in your car then a days racing could well drain it to the point that your car wont start. Believe me i did it to my dad many times
It's also worth pointing out that car batteries arn't designed to be used in this manner.

A leisure battery is your best way forward, you can get a 110amp one for about £40 if you know where to look.

[YZ~10]

yeah you really need a leisure battery, you can get away with charging a couple of 7.2v packs but otherwise be ready to bump start your car seen it happen many a time

[markwilliamson2001]

Other option is of course a generator, but the cheap ones are generally very noisy and smelly!
HTH
Mark

[Southwell]

The biggest problem with a geni is it's a continuous cost. Unless you want to run a laptop and lighting then i wouldn't bother. I only take mine to nationals.

[chb]

Originally Posted by BossCat_Works

yeah you really need a leisure battery, you can get away with charging a couple of 7.2v packs but otherwise be ready to bump start your car seen it happen many a time

Indeed... And remember that LeadAcid=realCar car batteries suffer when going flat. They are not designed for that.

Alternative is
==========
1) to get 2 or 3 old car batteries in your boot & charge off that. 1 fully charged real car battery is roughly 50AmpHour, so you should be able to do 10 Lipo charges with it before you reach the bottom 30% of the LeadAcid. (1 lipo charge=5Ah at 8V, so with modern chargers ~3Ah off the 12V LeadAcid battery).

2) charge off the cigarette lighter but do run the engine every so often to keep you car battery charged

[DomRC]

Ok cheers guys.. Next questions would be:

1) where would you recommend I find a good deal?

2) how do the plugs on the bantam attach to the battery? Do you need adaptors/clips or do they just plug in?

Cheers

[mark christopher]

trouble is most modern cars the cig lighter is only live with ignition on, and there not designed to power such as the chargers, best be is a 12 volt leisure battery from a caraven centre

just unplug the mains cable and plug the red croc clip to positive and black to negative

[Lee]

I also doubt the wiring would be able to cope with the constant current draw, i may be wrong but it would concern me, having said that i have driven to a race meeting with my charger lead out the door and under the bonnet and connected to the 12 v and a pack of nicads charging away on the dash

[mark christopher]

Originally Posted by Lee

I also doubt the wiring would be able to cope with the constant current draw, i may be wrong but it would concern me, having said that i have driven to a race meeting with my charger lead out the door and under the bonnet and connected to the 12 v and a pack of nicads charging away on the dash

think ford are rated 15 to 20 amps fuse dependent on car

[Lee]

Mine are just whatever i have left in the spare section

[chb]

car fuse and wiring should not be an issue

5A 8V charge is 3.5A 12V on the cigarette lighter. I often travel long journey with a 240V inverter attached to the cigarette lighter for my laptop (it's 100W consumed so twice as much as a lipo charger)

[DaveG28]

Plus start your car and run it for a few mins a couple of times during the day and you won't run your battery flat.

The car battery still won't like it though long term, so leisure battery is best!

[DomRC]

Originally Posted by chb

1 fully charged real car battery is roughly 50AmpHour, so you should be able to do 10 Lipo charges with it before you reach the bottom 30% of the LeadAcid. (1 lipo charge=5Ah at 8V, so with modern chargers ~3Ah off the 12V LeadAcid battery)

Just to clarify, do you always use 5ah with one lipo charge or does it depend on whether its a full charge or just a top up? 110ah batteries that I've seen are more than the £40 that Southwell suggested (unless I'm looking in the wrong place), so I'm wondering if an 85ah would last me a long time instead....

[Southwell]

Originally Posted by DomRC

Just to clarify, do you always use 5ah with one lipo charge or does it depend on whether its a full charge or just a top up? 110ah batteries that I've seen are more than the £40 that Southwell suggested (unless I'm looking in the wrong place), so I'm wondering if an 85ah would last me a long time instead....

I always charge at 4.2a with my lipos, no matter what. My 110a battery was more like £80 but ive heard of many people who got them around £40.

[stox217]

Yes you can charge thorough the cigarette lighter but you have to keep an eye out on the car battery or just start the car every now & then and let it idle charging up/ toping up the battery

[DomRC]

Originally Posted by Southwell

I always charge at 4.2a with my lipos, no matter what

I'll be charging off the battery at 5.0a for mine. My question is though, does the number of charges you get out of a leisure battery not depend on the length of each charge? How can people say exactly how many charges you'll get out of a 110ah battery?

Sorry if i'm being a bit dumb here

[Southwell]

I used to die after 1 and 3/4 days of charging at nationals on a 75ah battery at 5 amp. I would only go 110ah if you plan on doing more than one day.

[DomRC]

Originally Posted by Southwell

I used to die after 1 and 3/4 days of charging at nationals on a 75ah battery at 5 amp. I would only go 110ah if you plan on doing more than one day.

Ok so I'm likely to be doing a day of racing a month on average (regionals and practice/club meets)...so a lower ah should be fine.

And to charge the battery back up again it just plugs into the mains?

[Southwell]

Originally Posted by DomRC

Ok so I'm likely to be doing a day of racing a month on average (regionals and practice/club meets)...so a lower ah should be fine.

And to charge the battery back up again it just plugs into the mains?

Yeah, get a decent mains charger. Remember to unplug it from the mains before you disconnect from the battery or you could short it out and get bits of plastic and acid in your face.