DIY Battery Backup for DC Return Pump

[Scrubber_steve]

I have a 24VDC return pump & need a battery backup to keep it running during power outages.
The diagram below shows the AC power entering the pumps Driver, & 24.18V DC leaving it.
My thought is to place two 12V batteries connected in series in between the pumps Driver & the pumps Controller. The Driver will keep the batteries charged, & when the AC power cuts out, the batteries take over & run the pump.

So (1), is there any possible problem with this design?
and (2), the output from the Driver is 24.18 volts, & the batteries Standby voltage is 27 - 27.8 volts (fully charged). Could the higher voltage of the batteries damage the controller (do I need a voltage regulator in line?).

Thanks for any feedback.

 

[P-Dub]

You are missing a charge controller. I'm no electrician though...

 

[Scrubber_steve]

You are missing a charge controller. I'm no electrician though...

Possibly a voltage regulator to bypass the battery when fully charged.

I need the advice of an electrician ;Nailbiting

 

[Dr. Dendrostein]

I have a 24VDC return pump & need a battery backup to keep it running during power outages.
The diagram below shows the AC power entering the pumps Driver, & 24.18V DC leaving it.
My thought is to place two 12V batteries connected in series in between the pumps Driver & the pumps Controller. The Driver will keep the batteries charged, & when the AC power cuts out, the batteries take over & run the pump.

So (1), is there any possible problem with this design?
and (2), the output from the Driver is 24.18 volts, & the batteries Standby voltage is 27 - 27.8 volts (fully charged). Could the higher voltage of the batteries damage the controller (do I need a voltage regulator in line?).

Thanks for any feedback.

I have a 24VDC return pump & need a battery backup to keep it running during power outages.
The diagram below shows the AC power entering the pumps Driver, & 24.18V DC leaving it.
My thought is to place two 12V batteries connected in series in between the pumps Driver & the pumps Controller. The Driver will keep the batteries charged, & when the AC power cuts out, the batteries take over & run the pump.

So (1), is there any possible problem with this design?
and (2), the output from the Driver is 24.18 volts, & the batteries Standby voltage is 27 - 27.8 volts (fully charged). Could the higher voltage of the batteries damage the controller (do I need a voltage regulator in line?).

Thanks for any feedback.

If my device add 120v coil, N.C. relay. Power relay coil with a cord, plug into same outlet as pump.
When there's power to pump, relay has power too. So relay breaks circuit to batteries so batteries and power from home not powering pump. When power out to outlet, the relay deactivates. Permitting power from batteries to pump.

 

[Dr. Dendrostein]

Also, buy two more batteries, all of them(4) deep cycle type. Use two, when batteries need charge change with other two.then charge the ones low on charge. But, personally, lithium batteries way to go. Smaller, lighter. Big investment, but worth it.

Batteries should need very little charge, because their mainly stand by.

If you could get 1000amp cca, batteries. Rare to have to charge them. Maybe in two years.

 

[Dr. Dendrostein]

Also about a regulator, no need. DC pumps forgiving on voltage running thru them

 

[Ratherbeflyen]

Also, buy two more batteries, all of them(4) deep cycle type. Use two, when batteries need charge change with other two.then charge the ones low on charge. But, personally, lithium batteries way to go. Smaller, lighter. Big investment, but worth it.

I guess I don't see the point of having two sets of batteries. If the power is out for an extended time, how are you going to charge up the first set of batteries? If you have a power source that can charge the batteries, why not just use that power source to run the pump or entire tank? I would, and did, get one battery backup to sustain the tank until I have the chance to connect a small generator.

 

[Dr. Dendrostein]

Right, good idea

 

[Scrubber_steve]

If my device add 120v coil, N.C. relay. Power relay coil with a cord, plug into same outlet as pump.
When there's power to pump, relay has power too. So relay breaks circuit to batteries so batteries and power from home not powering pump. When power out to outlet, the relay deactivates. Permitting power from batteries to pump.

That design would prevent the power from the driver charging the batteries (although the driver voltage isn't high enough to fully charge the batteries anyhow)

I understand how relays work, but what is the purpose of the 120v coil?

 

[Dr. Dendrostein]

That design would prevent the power from the driver charging the batteries (although the driver voltage isn't high enough to fully charge the batteries anyhow)

I understand how relays work, but what is the purpose of the 120v coil?

Relay is activated as long as main power of home on. When a black out occurs it deactivates and permits batteries to kick in. This is simplest design. MO

 

[Scrubber_steve]

Relay is activated as long as main power of home on. When a black out occurs it deactivates and permits batteries to kick in. This is simplest design. MO

Yes , but why is the 120v coil needed, what is its purpose in relation to the relay?

 

[Huskymaniac]

On a dc pump i would just get a good computer ups. The one i have can run my pump for close to 4 hours.

 

[Dr. Dendrostein]

Yes , but why is the 120v coil needed, what is its purpose in relation to the relay?

The coil is part of relay, coil activates relay contacts

 

[Scrubber_steve]

The coil is part of relay, coil activates relay contacts

Ok the coil is part of the relay, but why not a 24v rather than a 120v?

 

[Dr. Dendrostein]

Ok the coil is part of the relay, but why not a 24v rather than a 120v?

Just hit me, use a 24v dc relay, safer, much more simpler, two heads better than one

 

[Scrubber_steve]

Just hit me, use a 24v dc relay, safer, much more simpler, two heads better than one

I have 240V in any case

 

[Dr. Dendrostein]

I have 240V in any case

Huh? What you talk'in about Willis

 

[Dr. Dendrostein]

There is a problem with using 24v dc relay if powered by batteries. Or the power source from pump

 

[Scrubber_steve]

Huh? What you talk'in about Willis

Australia

 

[Scrubber_steve]

There is a problem with using 24v dc relay if powered by batteries. Or the power source from pump

yes then, tell me more?