Battery bank ventilation fan controller

[shadyocuk]

Hi all ,

I would like to construct a circuit that will switch on a fan when a battery bank is being charged and switch it off again after a delay period (say 10 mins) when charging has stopped.

The battery bank is 12 volts and the float charge is 13.6 volts and the max charge is 14.8 volts.

The fan I plan to use is a brushless 12 volt 0.06 amp pc fan.

I believe I need a schmitt trigger that would have an on trigger of >=13.6 volts and an off trigger of <= 13.2 volts , but I do not know how to design the said circuit.

Can any kind sole point me in the direction of a schematic that would do the trick ?

Many thanks

Shady

 

[rjvh]

why would you switch it only on the charge cycle it makes more sense that you let it swich on temparature of the battery bank housing as this is much more critical for your batterys as your charge voltages are fixted (assumtion)

the battery bank housing should already be ventilated enough for reliesing the produced gasses durring charging in the first place

another aproach could be that you make a charge voltages corection depending on the temparature of the battery

Robert-Jan

 

[shadyocuk]

why would you switch it only on the charge cycle it makes more sense that you let it swich on temparature of the battery bank housing as this is much more critical for your batterys as your charge voltages are fixted (assumtion)

the battery bank housing should already be ventilated enough for reliesing the produced gasses durring charging in the first place

another aproach could be that you make a charge voltages corection depending on the temparature of the battery

Robert-Jan

The battery bank is inside a caravan and I wont to force ventilate the gases produced during charging to the outside of the van , hense the desire to only run the fan whilst the batteries are actually charging.

Shady

 

[mneary]

Problem with a voltage triggered fan is that it wouldn't run until the battery bank is near full charge.

 

[saturn1bguy]

Problem with a voltage triggered fan is that it wouldn't run until the battery bank is near full charge.

That's only if the fan is running from the batteries that are being charged. The OP never said that that was the case. Since power is coming from somewhere to charge the batteries, that same power can run the fan. I think all the OP is looking for is an appropriately sized window discriminator to turn his fan on and off.

 

[mneary]

That's only if the fan is running from the batteries that are being charged. The OP never said that that was the case.

I believe I need a schmitt trigger that would have an on trigger of >=13.6 volts and an off trigger of <= 13.2 volts , but I do not know how to design the said circuit.

uhh, did we read the same thread?

 

[saturn1bguy]

uhh, did we read the same thread?

I think so. I wouldn't get too hung up on his advertised threshold levels, as one could make those adjustable. Once he has the circuit he might see that he wants to move them around a bit...