To remove spark from battery

hello every one,
I want to make a battery charger circuit which will totally intrinsically safe(free from any spark or surge). I have to charge a 24Volts battery (two [email protected] acid sealed Batteries connected in series). Here in the circuit i have connect a mechanical switch to on-off my load, but when i turn the switch on/off there is a spark generates near the switch and i want to remove this spark. How can i do this please suggest me by giving your valuable time. The circuit diagram is attached here.

Thank you

I always understood the term "intrinsically safe" to mean a circuit of such low power
that it can't create a spark hazard.
You can never do that with a battery charger.
I suppose a fully sealed relay would be safe in most situations, but why use a relay ?.

What are items D1,D2 and R3 for ?

Why have a regulator (LM2576) outputting 7.0 volts,
why not 5 volts ?

When the charger is on, the relay cuts the power to the output (bat_24)

Perhaps a rethink is needed.

@ ExperimentalUK
D2 is used here as a fly-back diode across relay's coil, R3 is for dropping some voltage and providing 20v-24v to relay to energies it and D1 is to protect the charger from reverse voltage if any coming. Also this circuit will works with battery mode only not with charger mode, that's why i disconnect the supply if while charger connected. there is my mistake with the 2576 to configure it for 7 volts, i have reconfigured it for volts.
One thing please clear me that if i have a load of 600mA-800mA @ 24Volts, then for back-uping it for 5-6 hours what rating of battery should i use?
I think to reduce these sparks, i will have to mention 2 switches to make and break both the vcc and ground simultaneusly. I will try it and let you know the status.
Thank you

@ ExperimentalUK
D2 is used here as a fly-back diode across relay's coil, R3 is for dropping some voltage and providing 20v-24v to relay to energies it and D1 is to protect the charger from reverse voltage if any coming.

diana1234

In this case you don't need a fly back diode and if you look carefully
D1 does nothing.
470 ohms seems a bit high.

Also this circuit will works with battery mode only not with charger mode

diana1234

Why bother disconnecting when charging ?

one thing please clear me that if i have a load of 600mA-800mA @ 24Volts, then for back-up it for 5-6 hours what rating of battery should i use?

diana1234

800mA * 6 hours is 4800 mAH @24 volts
= 4.8 amp hours.
Is it 600mA-800mA @ 24Volts or at 5 volts ?

Why are you using 24volt batteries ?

I think to reduce these sparks, i will have to mention 2 switches to make and break both the vcc and ground simultaneusly. I will try it and let you know the status.

diana1234

Using 2 switches will not prevent sparks.
Some kind of resister/capacitor filter across the switch will help a lot though.
Don't ask what values to use , I would just be guessing

Why do you need a super safe switch ?