Car battery + invertor to run an electric reclining sofa?

[MkGriff]

I'm looking at two sofa's to sit in the middle of a room, that have electric recliners.

I do not want cables running across the floor to the nearest plug socket and cannot bury the cables as I have a solid wooden floor that is glued to concrete.

So, could I power these by locating a car battery underneath with an inverter?

Each sofa has two motors and two separate power leads.

Apparently the motors are 24V and 2amp (I believe that equates to 48watts?!?).

Any advice welcomed.

[tribbles]

If you use two 12V batteries, no need for an invertor.

Or a single 24V battery...

ETA: Or are the motors AC motors (in which case you'd need an invertor)?

Edited by tribbles on Thursday 30th December 15:43

[GarryA]

If you want them to be slower you could run them straight off one battery at 12V but you will double the current so 4A

This would take some modifying of the circuit though.

Seems daft going 12v up to 240v then down to the 24v again.

Presumed DC motor

Edited by GarryA on Thursday 30th December 15:44

[MkGriff]

Thanks guys.

[oldcynic]

GarryA said:

If you want them to be slower you could run them straight off one battery at 12V but you will double the current so 4A

This would take some modifying of the circuit though.

Seems daft going 12v up to 240v then down to the 24v again.

Presumed DC motor

Surely if you drop to 12V the motor will still only draw 2A as it will be running at reduced power (hence running more slowly)

[98elise]

oldcynic said:

GarryA said:

If you want them to be slower you could run them straight off one battery at 12V but you will double the current so 4A

This would take some modifying of the circuit though.

Seems daft going 12v up to 240v then down to the 24v again.

Presumed DC motor

Surely if you drop to 12V the motor will still only draw 2A as it will be running at reduced power (hence running more slowly)

No it will draw 1 amp (I=V/R). R will be constant so as the V drops so will I.

[GarryA]

98elise said:

oldcynic said:

GarryA said:

If you want them to be slower you could run them straight off one battery at 12V but you will double the current so 4A

This would take some modifying of the circuit though.

Seems daft going 12v up to 240v then down to the 24v again.

Presumed DC motor

Surely if you drop to 12V the motor will still only draw 2A as it will be running at reduced power (hence running more slowly)

No it will draw 1 amp (I=V/R). R will be constant so as the V drops so will I.

What if a 20 stone man is sat on the chair at the time

[Pickled Piper]

You don't need a car battery for that sort of current draw. a couple of 12V house alarm batteries from Maplins will do the job for you. However, having to charge the batteries will be more of a ball ache than having mains leads running across your lounge floor. Also, more potential for a big spark and fire and or acid spillage with car batteries.

pp

[Fatboy]

Pickled Piper said:

You don't need a car battery for that sort of current draw. a couple of 12V house alarm batteries from Maplins will do the job for you. However, having to charge the batteries will be more of a ball ache than having mains leads running across your lounge floor. Also, more potential for a big spark and fire and or acid spillage with car batteries.

pp

How about some 24V power tool batteries - fast charge, easy change and no risk of acid spill etc...?

[oldcynic]

Sealed Lead Acid batteries would probably be the simplest solution - along with a dedicated charger. From what I remember they work in any orientation except upside down and no danger of spillage. Add a sensible fuse into the circuit to avoid unwanted seat-warming problems and you're sorted.

[MkGriff]

Thanks again for all the advice.

Does anyone know what kind of life I could expect out of the different batteries recommended, between charges?

If I use 2 12v batteries, then how do I connect those together and then how do I connect them to the 3pin sofa plugs?

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

[Simpo Two]

MkGriff said:

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

I'd suggest that they also contain the transformer, in which case your plans may be buggered...

[dave_s13]

Simpo Two said:

MkGriff said:

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

I'd suggest that they also contain the transformer, in which case your plans may be buggered...

From what he's describing the motors need a 230v AC feed then (mains).

You could probably do it with some dismantling of the motors and a bit of soldering but you're then in the position of having A). Chucked away any warranty and B). Potentially burning the house down given you're knowledge of how electricity works seems limited (not that I'd know what to do like!!).

Other option is a handle, and an arm/hand.

[oldcynic]

How about reclining sofas without motors? You know - those old fashioned lever things.

[MkGriff]

dave_s13 said:

Simpo Two said:

MkGriff said:

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

I'd suggest that they also contain the transformer, in which case your plans may be buggered...

From what he's describing the motors need a 230v AC feed then (mains).

You could probably do it with some dismantling of the motors and a bit of soldering but you're then in the position of having A). Chucked away any warranty and B). Potentially burning the house down given you're knowledge of how electricity works seems limited (not that I'd know what to do like!!).

Other option is a handle, and an arm/hand.

If the transformer is built into the motor, meaning that 240V is required, then would the inverter sort that out if connected to a car battery?

[GarryA]

Just wondered if the inverter has some form of current limiter too for the motor circuit.

OP how new is your house? It could be a lot easier to sort out a socket.

[ZesPak]

MkGriff said:

dave_s13 said:

Simpo Two said:

MkGriff said:

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

I'd suggest that they also contain the transformer, in which case your plans may be buggered...

From what he's describing the motors need a 230v AC feed then (mains).

You could probably do it with some dismantling of the motors and a bit of soldering but you're then in the position of having A). Chucked away any warranty and B). Potentially burning the house down given you're knowledge of how electricity works seems limited (not that I'd know what to do like!!).

Other option is a handle, and an arm/hand.

If the transformer is built into the motor, meaning that 240V is required, then would the inverter sort that out if connected to a car battery?

Mmm yes, but it would deem to me that it'd be less than ideal.
Dismantling/replacing the motors would be a better option then in my book.
Also, I'd be surprised that the transformer would be in the motor, is that common?

[MkGriff]

GarryA said:

Just wondered if the inverter has some form of current limiter too for the motor circuit.

OP how new is your house? It could be a lot easier to sort out a socket.

Hi Garry,

The sofa's will sit in the middle of a room with a wooden floor that is glued to concrete, so I am not about to start chasing cables!

Re the current limiter, of course I have no idea. If the motor is 24V and 2Amp, is it true to say that the wattage is 48, or is this not a simple calculation?

[MkGriff]

ZesPak said:

MkGriff said:

dave_s13 said:

Simpo Two said:

MkGriff said:

In my ignorance, I assume that the inverter will raise the 12v output of the battery to 240v and then between the plug and the motor, there will be a transformer that pars that back down to 24v. Can I bypass this?

Apparently, the motors are AC input and DC output - if that helps.

I'd suggest that they also contain the transformer, in which case your plans may be buggered...

From what he's describing the motors need a 230v AC feed then (mains).

You could probably do it with some dismantling of the motors and a bit of soldering but you're then in the position of having A). Chucked away any warranty and B). Potentially burning the house down given you're knowledge of how electricity works seems limited (not that I'd know what to do like!!).

Other option is a handle, and an arm/hand.

If the transformer is built into the motor, meaning that 240V is required, then would the inverter sort that out if connected to a car battery?

Mmm yes, but it would deem to me that it'd be less than ideal.
Dismantling/replacing the motors would be a better option then in my book.
Also, I'd be surprised that the transformer would be in the motor, is that common?

'Simpo Two' suggested that the transformer might be integrated with the motor.

I will get in touch with the manufacturer again and see what additional information I can get. It seems that until we know exactly what we are faced with, the solutions are variable.

In the words of Arnie "I'll be back".

[GarryA]

The motor will have different current demands depending what its doing.

Upon starting it will draw a higher current than when its running, same if you put a heavy load on it i.e fat b'stard on the chair or perhaps it jams up.

Your inverter is 240V / 24V

The 24V is 2A so the pull on the 240 is going to be 0.2A or the 48W you said earlier.

You can get a 150W 12v/240v inverter for £20 and you would need a battery, car batteries are not suitable really as they don't like being discharged then charged up all the time so you would need a maintenance free sealed battery and a charger.

The higher the Ah on the battery the longer its going to last.

I think it would be worth £50 trying it out.