Small pump 12V and 240 transformer

[MagicalArmchair]

This has all the hallmarks for me blowing myself up. So I have a small pump to empty my fresh water tank out when I treat it this year.

It says: DC6 - 12V 15W.

Now, I don't want to drain my 12V batteries to pump out the water, and want to plug it into a handy transformer I have from an old Internet router. This says:

OUTPUT: DC12V 1.0A

Now, at 12V, 15W is err about 1.25A. If I use the transformer above, with my little pump, will I set my face on fire? Should I just run a wire from my domestic batteries and stop buggering about with 240V? What could go wrong?

The pump:

The transformer:

 

[alahol2]

Well at 1.25A, if you run it for an hour you will use 1.25Ah from your battery. What's that? 1%, 5%, it shouldn't be running your battery flat. My guess is that the pump won't be powerful enough.

 

[lw395]

Running a 1A power supply at 1.25A is likely to cause it to shut down, or maybe fuse, possibly even catch fire. It might work for a few minutes until it heats up.
You might find a 2A rated 12V 'wall wart' from an older broadband router or something?
I would run the pump off the batteries and then charge them.

 

[RichardS]

It won't do any harm to try the PSU and keep an eye/hand on it to check that it's not overheating. However, it might not be a pure DC waveform so might drive the pump at a slower speed than you were expecting.

Richard

 

[VicS]

This has all the hallmarks for me blowing myself up. So I have a small pump to empty my fresh water tank out when I treat it this year.

It says: DC6 - 12V 15W.

Now, I don't want to drain my 12V batteries to pump out the water, and want to plug it into a handy transformer I have from an old Internet router. This says:

OUTPUT: DC12V 1.0A

Now, at 12V, 15W is err about 1.25A. If I use the transformer above, with my little pump, will I set my face on fire? Should I just run a wire from my domestic batteries and stop buggering about with 240V? What could go wrong?

The pump spec looks reasonable for the job but the power supply is not actually a transformer type . It is a switch mode power supply brick. It may not be up to the task but the only way to find out is to try it.

We always used to MT the water tank by running one of taps to waste while we took the boat from its mooring to the board yard thereby not draining any power from the battery. We probably should not have run the pressure pump continuously but it survived .

The battery drain would be quite small as pointed out and if you have power for the PSU then you have power for a battery charger to top them up again afterwards

 

[Graham376]

This has all the hallmarks for me blowing myself up. So I have a small pump to empty my fresh water tank out when I treat it this year.

Assuming you have a battery charger on board, why not just switch that on whilst pumping out?

 

[MagicalArmchair]

Assuming you have a battery charger on board, why not just switch that on whilst pumping out?

Thank you all, and yes, that's likely a better solution. Thanks all for the responses, sounds like I'm overthinking it as usual....!