Is there any way a battery can charge other battery through isolated Charging circuit powered by a battery?

Hi Uche,

I'm a master power electronics engineer and I specialize in DC-DC converters, solar charge converters, DC-AC Inverters, Power Supplies, and battery chargers. Yes, you can charge a battery from another battery, if that's what you're asking. I don't know why you need it isolated. However, I've got to agree with D2113F with reference to your other replies to this post. To me, it sounds like a perpetual motion machine wheras you have two batteries that are each connected to relays that can switch the individual batteries to either a load or to a a charging circuit fed by the other battery. Here is the problem. Battery-1 is connected to a load and is discharged to the point that you want to rechage it from the other battery that's been idle. Battery-2 recharges Battery-1 thru a dc-dc converter with a control to ensure that it's not overcharged. Now, Battery-2 is discharged and Battery-1 is charged, therefore, the relay or relays setup the circuit such that Battery-1 recharges Battery-2 and now Battery-1 is again discharged. Hopefully, you see where I'm going with this. It's an (almost) endless loop of the batteries charging and discharging each other. And if you powered a load first, discharging Battery-1, then recharged it with Battery-2, Battery-2 is now discharged and you can power the load only one more time with Battery-1. But now, you can no longer recharge Battery-1 with Battery-2 since Battery-2 is discharged, The only way around this is if you have some additional power from another Battery, or a Solar Cell, or from an AC-DC Power Supply to put the lost energy back into the system.

One of the first things you should have learned in physics is that there is no such thing as a perpetual motion machine. Since you used the energy in Battery-1 to power the load and the energy in Battery-2 to recharge Battery-1, and since you used-up the energy in Battery-1 again powering the load after the recharge, you are out of energy as both Battery-1 and Battery-2 are discharged. Does this make any sense to you? I hope so, but if not, please feel free to reply here or send me a message using the Element-14 internal messaging system.

Best regards,

Kamran Kazem

am thinking of connecting an AC powered rotating motor to a car alternator which will be used to charge the batteries and the AC powered rotating motor will be connected to an inverter which will be powered by same battery that is being charged by the alternator.

Austine,

Yes, of course a battery’s energy can be used to charge another battery thru an isolated or non-isolated charging circuit. But some of what I’m reading below is bordering on being a perpetual motion machine and that violates scientific principles. It simply will not work.  Your system described below with the ac motor, car alternator, & car battery will work initially assuming the battery is initially charged. But the losses in the inverter, from the IR drops in the motor and alternator, & from friction will cause the battery to eventually discharge and go dead. You would then have to re-charge the battery from another energy source (like the 120 VAC utility power line or another battery). Once re-charged, you could then re-start the system again until the battery went dead from the losses.

So what’s the point? There is no free energy here. If you have the parts, you can build this relatively inexpensively and see for yourself. Many others have had the same basic idea, but always with the same results. There is no such thing as perpetual motion. A better way to get almost limitless, renewable energy is to use the sun, wind, waves, geothermal, and other similar energy sources that are all around us and can easily be converted into useful electricity. 

Regards,

Kamran Kazem, V.P.

Magnetic Design Labs, Inc.

Austine,

Yes, of course a battery’s energy can be used to charge another battery thru an isolated or non-isolated charging circuit. But some of what I’m reading below is bordering on being a perpetual motion machine and that violates scientific principles. It simply will not work.  Your system described below with the ac motor, car alternator, & car battery will work initially assuming the battery is initially charged. But the losses in the inverter, from the IR drops in the motor and alternator, & from friction will cause the battery to eventually discharge and go dead. You would then have to re-charge the battery from another energy source (like the 120 VAC utility power line or another battery). Once re-charged, you could then re-start the system again until the battery went dead from the losses.

So what’s the point? There is no free energy here. If you have the parts, you can build this relatively inexpensively and see for yourself. Many others have had the same basic idea, but always with the same results. There is no such thing as perpetual motion. A better way to get almost limitless, renewable energy is to use the sun, wind, waves, geothermal, and other similar energy sources that are all around us and can easily be converted into useful electricity. 

Regards,

Kamran Kazem, V.P.

Magnetic Design Labs, Inc.