battery in boot

[captain1]

Hi

i belive it is possable to recharge the leisure battery in the boot of the car when we are out touring solo as we like small fields with no hook up this would be very helpfull to keep the battery charged. any one know how this done thanks in advance

john

 

[ThePlotter]

You just need a split charge relay (readily available)and wire it into the alternator (you will be given instructions) then a heavy guage wire is fed to the boot and connected to the battery.

 

[RonD]

John,

A battery in the boot of your car is potentially very dangerous.

The wiring to it must have an inline fuse close to the battery to protect from any possible short circuits which has the potential of causing a fire. Bear in mind your fuel tank is probably underneath. How are you going to secure the battery which contains sulphuric acid?

I wouldn't even consider it.

 

[captain1]

The battery would be secure in a plastic battery box and lashed down so should not be a huge risk but i agree there is risk however small

Is there a split charge relay already on the car,can i take it off there i was hoping perhaps the s type plug on the tow bar

Ron d I do take your point about safty thanks for the reminder

john

 

[SirRogerFFS]

Hi John, here is my idea, a split charge relay you only get when you do a wire it yourself job for the grey plug.

So unless I am compltely wrong you should be able to do this job without coming off the alternator.

The relay fitted to your tow vehicle if fitted by a towbar fitter is far more complex than a split charge relay .

So .I hope this will will help you in some way.

Regards Sir Roger

 

[ProfJohnL]

Hello John,

I have done exactly what you have suggested. I not only use this for caravanning, but for other jobs I have.

I have used a plastic box to hold and secure the battery, It was held in position with a webbing strap to stop it toppling or moving about. It had a close fitting lid and I arranged for a ventilator pipe to the outside to get rid of any hydrogen gas from charging.

I used insulated clamp on terminal connectors (as used in many caravans) to make the connection to the battery, Both conductors were 2.5mm and fused at 10A and the cable was terminated with a 7S plug.

The cable was brought out of the boot space through the soft seal of the tailgate and plugged into the 7S socket. The charging relay in the car did all the switching that was necessary.

This worked well for me, but if you are only doing short runs (down to the beach etc) then it will only put a limited charge into the battery. - but it was certainly better than nothing.

 

[Guest]

I would point out that in certain cars, my Volvo for example, the battery is located in the boot as standard. It is secured under a plastic cover alonside the spare wheel, so i guess the engineers at Volvo have discounted the proximity of the fuel tank as being very low risk. When located at the front there is always the possibility of fuel hitting a hot engine/exhaust, so the risk is similar.

What you will have to do is ensure the battery is secured safely, with a metal frame, so it cannot break loose. The wiring, as mentioned will need to be a heavy duty cable from the existing battery at the front and linked through a relay. Remember, the system is designed so that the charging is biased heavily towards the car battery, as expected, so it will take a long run to get much of a charge into the leisure battery.

Have you thought about a secondary charging system such as a wind or solar powerd system that could trickle charge the battery while you are on site?

 

[DeliDave]

starting systems such as Maplins or Halfords just plug inot an auxiliary socket in the boot or dashboard.I would just start up first and with a decent run it should be fine.Securing it well is essential as it may not be sealed as the starting systems are.

 

[BigAl1]

John.

Assumming that your grey socket is connected correctly, you have everything allready in place.

I have done what you suggest before, all you need to do is make up a lead 2 cables connected to a grey plug.

connect pin 6 to your spare battery poss + terminal and pin 7 to the battery neg - terminal.

Run the lead from outside the car to inside via a suitable method.

Al

 

[BigAl1]

John,

A battery in the boot of your car is potentially very dangerous.

The wiring to it must have an inline fuse close to the battery to protect from any possible short circuits which has the potential of causing a fire. Bear in mind your fuel tank is probably underneath. How are you going to secure the battery which contains sulphuric acid?

I wouldn't even consider it.

Ron D

Many cars have the battery inside the car, usually beneath the driver's saat.

 

[BigAl1]

John,

A battery in the boot of your car is potentially very dangerous.

The wiring to it must have an inline fuse close to the battery to protect from any possible short circuits which has the potential of causing a fire. Bear in mind your fuel tank is probably underneath. How are you going to secure the battery which contains sulphuric acid?

I wouldn't even consider it.

Ron.

Many cars have their battery fitted inside the cab. Usually beneath the driver's seat.

 

[JTQ]

Charging from a "split charge relay" goes some way to recharging the "spare" battery. However its not that effective because the vehicle battery ought to be nearly fully charged, thus the regulatory circuit will quickly back off the available charge, limiting what gets put in the spare.

It can be more effective to use an inverter feeding a battery charger. By doing this the voltage driving the spare battery will be what the spare requires quite immune to what the regulatory circuit senses the vehicle battery requires. Typically the spare will be seeing 14.4 or more volts whilst the fully serviced vehicle battery could be seeing of the order of 13.5 volts.

This works fine and fully charges the spare as long as it is not too depleted. It is a technique best used to frequently top up the spare each time the vehicle is used rather that a major recovery method.

The split charge method can however give a higher current charge to a highly discharged spare, but you ought not be abusing the spare battery in that way.

My system is a 150 watt modified sine wave inverter plugged into the rear 12 volt socket and one of my trusty C-Tek 3600 chargers. Both these are useful very light weight bits of kit carried for other tasks anyway.

As others have stated the spare must be very firmly fixed in the vehicle. I find it best just to leave it there and use it by plugging a lead onto it institute, thus no hernia, it remains securely fixed and it's serviced without any further thought on my part.

 

[JTQ]

Charging from a "split charge relay" goes some way to recharging the "spare" battery. However its not that effective because the vehicle battery ought to be nearly fully charged, thus the regulatory circuit will quickly back off the available charge, limiting what gets put in the spare.

It can be more effective to use an inverter feeding a battery charger. By doing this the voltage driving the spare battery will be what the spare requires quite immune to what the regulatory circuit senses the vehicle battery requires. Typically the spare will be seeing 14.4 or more volts whilst the fully serviced vehicle battery could be seeing of the order of 13.5 volts.

This works fine and fully charges the spare as long as it is not too depleted. It is a technique best used to frequently top up the spare each time the vehicle is used rather that a major recovery method.

The split charge method can however give a higher current charge to a highly discharged spare, but you ought not be abusing the spare battery in that way.

My system is a 150 watt modified sine wave inverter plugged into the rear 12 volt socket and one of my trusty C-Tek 3600 chargers. Both these are useful very light weight bits of kit carried for other tasks anyway.

As others have stated the spare must be very firmly fixed in the vehicle. I find it best just to leave it there and use it by plugging a lead onto it institute, thus no hernia, it remains securely fixed and it's serviced without any further thought on my part.

PS; I should have pointed out that in my vehicle the 12 volt rear plug automatically gets isolated when the ignition is switched off so I don't even have to thick about plugging and unplugging that.

 

[JTQ]

Charging from a "split charge relay" goes some way to recharging the "spare" battery. However its not that effective because the vehicle battery ought to be nearly fully charged, thus the regulatory circuit will quickly back off the available charge, limiting what gets put in the spare.

It can be more effective to use an inverter feeding a battery charger. By doing this the voltage driving the spare battery will be what the spare requires quite immune to what the regulatory circuit senses the vehicle battery requires. Typically the spare will be seeing 14.4 or more volts whilst the fully serviced vehicle battery could be seeing of the order of 13.5 volts.

This works fine and fully charges the spare as long as it is not too depleted. It is a technique best used to frequently top up the spare each time the vehicle is used rather that a major recovery method.

The split charge method can however give a higher current charge to a highly discharged spare, but you ought not be abusing the spare battery in that way.

My system is a 150 watt modified sine wave inverter plugged into the rear 12 volt socket and one of my trusty C-Tek 3600 chargers. Both these are useful very light weight bits of kit carried for other tasks anyway.

As others have stated the spare must be very firmly fixed in the vehicle. I find it best just to leave it there and use it by plugging a lead onto it institute, thus no hernia, it remains securely fixed and it's serviced without any further thought on my part.

Ah spelling, of course I meant " in-situe", or however that's spelt.

 

[WatsonJohnG]

I used an 85 amp hour battery and a boot charging system for several years when we used to use CLs exclusively

I used heavy cables from the car battery(via a relay) to the 12S socket and connected into them in the boot

I then had a fused socket in the battery box (plastic bread bin)with a matching shielded plug in the car boot(belkin)

We had 2 such battery boxes and swapped them over every 3 or 4 days and if going for a long drive.

They were secured well in the car boot

 

[captain1]

Hi All thanks thats great what a nice bunch you are between you i have now got it sussed a special thanks to Big Al and JohnL.

I have a spare 85 amp battery and some 7 core white cable even a in line fuse holder so it looks like i need a 7 pin s plug and some red and blue terminals and not forgetting a 10 amp fuse

Scotch lad i like the idea of a solar panel but must save the pennies first i understand 20 to 30amp minimum is worth spending the pennies on

john

 

[captain1]

Hi All thanks thats great what a nice bunch you are between you i have now got it sussed a special thanks to Big Al and JohnL.

I have a spare 85 amp battery and some 7 core white cable even a in line fuse holder so it looks like i need a 7 pin s plug and some red and blue terminals and not forgetting a 10 amp fuse

Scotch lad i like the idea of a solar panel but must save the pennies first i understand 20 to 30amp minimum is worth spending the pennies on

john

Hi

i think i should heve said 20to 30 watt solar panel

i was having another senior moment

John

 

[captain1]

i ment so say 20 to 30 amp

thanks again

john

 

[RonD]

Ron.

Many cars have their battery fitted inside the cab. Usually beneath the driver's seat.

Big Al,

Yes, I'm aware of the many cars including Volvos that have their battery at the rear of the car...secured under the floor, in a specially designed compartment. My point was that a battery standing in the boot, even in a box, is not the same. In the event of a sudden stop, this would become a missile. A friend had a briefcase in the boot of his car which had to do an emergency stop. The briefcase came completely through the back seat!

 

[captain1]

thanks for all your help and advice

I have set system up as sugested had a 10 mile ride out and the spare battery was up to 12.7 volts

cant wait for our next long break

john

 

[KevinKTWO]

Big Al,

Yes, I'm aware of the many cars including Volvos that have their battery at the rear of the car...secured under the floor, in a specially designed compartment. My point was that a battery standing in the boot, even in a box, is not the same. In the event of a sudden stop, this would become a missile. A friend had a briefcase in the boot of his car which had to do an emergency stop. The briefcase came completely through the back seat!

Buy a battery box and attach the box to the luggage tie points -