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Aquarium Pump Backup

M

mjoconr

New Member
Joined
Dec 26, 2019
Messages
8
Hi All

We had a power outage to day which lasted a little too long and I had fish die. If I had been home I would have wired the generator.
The pump is powered by a 24V DC power supply, how could I put a LiFePO4 battery between this the power supply the the pump controller.

The issue for me is that the 24V supply is probably not the correct voltage to charge a battery.

Can anyone give me a pointers how I might arrange this ?

Thanks
Mike
 
Here is a start.
Some telecom and security gear could work also. Look up dc ups in the voltage you need.

8800mAh ?

Amazon.com: Mini UPS Battery Backup 8800mAH Uninterruptable Power Supply System with POE Function AC 100V-240V Input DC 5V/9V/12V/15V/24V Output for Webcam, Modem, IP Camera, Wireless Router (5V-24V POE): Home Audio & Theater

Amazon.com: Mini UPS Battery Backup 8800mAH Uninterruptable Power Supply System with POE Function AC 100V-240V Input DC 5V/9V/12V/15V/24V Output for Webcam, Modem, IP Camera, Wireless Router (5V-24V POE): Home Audio & Theater
www.amazon.com

This looked useful. Im sure smaller or larger is available.

MEAN-WELL-DR-UPS40-

Amazon.com: MEAN WELL DR-UPS40 40 Amp DC Uninterruptable Power Supply : Electronics

Buy MEAN WELL DR-UPS40 40 Amp DC Uninterruptable Power Supply: Uninterruptible Power Supply (UPS) - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
 
There are many pumps available with battery backup as a option. That will be the easiest. You likely only need one of your pumps running to keep the fish alive.

We would need to know the numbers of amps to size a battery and then an accurate measurement of both DC and AC values going to the pump to determine if it is feasible. What is the model number and brand of the pump?
 
You could also feed the battery transfer switch with a 12v-24v dc-dc converter switching power supply.
 
kernel said:
Here is a start.
Some telecom and security gear could work also. Look up dc ups in the voltage you need.

8800mAh ?

Amazon.com: Mini UPS Battery Backup 8800mAH Uninterruptable Power Supply System with POE Function AC 100V-240V Input DC 5V/9V/12V/15V/24V Output for Webcam, Modem, IP Camera, Wireless Router (5V-24V POE): Home Audio & Theater

Amazon.com: Mini UPS Battery Backup 8800mAH Uninterruptable Power Supply System with POE Function AC 100V-240V Input DC 5V/9V/12V/15V/24V Output for Webcam, Modem, IP Camera, Wireless Router (5V-24V POE): Home Audio & Theater
www.amazon.com

This looked useful. Im sure smaller or larger is available.

MEAN-WELL-DR-UPS40-

Amazon.com: MEAN WELL DR-UPS40 40 Amp DC Uninterruptable Power Supply : Electronics

Buy MEAN WELL DR-UPS40 40 Amp DC Uninterruptable Power Supply: Uninterruptible Power Supply (UPS) - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
Click to expand...
That's for this, interesting products.
I'm really wanting to understand the rules so I can create my own. Because I have more than one tank and want to keep the costs down.
 
newbostonconst said:
There are many pumps available with battery backup as a option. That will be the easiest. You likely only need one of your pumps running to keep the fish alive.

We would need to know the numbers of amps to size a battery and then an accurate measurement of both DC and AC values going to the pump to determine if it is feasible. What is the model number and brand of the pump?
Click to expand...
Correct, there are options to purchase battery packs for pumps but your paying for someone else's time and I really would like to understand the problem.
 
So the question for me is if I have a pack which can generate 24 volts what are the following.
1. what is its max voltage ?
2. what is the min voltage ?
3. what voltage would I need to charge / keep the battery charged ?
4. is the max voltage a problem for the pump ?
 
Maybe a double pole 24v relay, normally energized with the power supply...when the grid goes down the relay loses it's trigger and it switches over to battery power. Simple and very cheap. You'd still have to charge the battery after use though.
 
SolarRat said:
Maybe a double pole 24v relay, normally energized with the power supply...when the grid goes down the relay loses it's trigger and it switches over to battery power. Simple and very cheap.
Click to expand...
Good idea, its not as if I need the pump to have its power maintained during the switch over like you would for a computer.
 
The simplest solution I can think of would be to get an LiFePO4 battery large enough to power your
pumps directly for the maximum duration you "could be" without power.
Get an AC powered charger for your LiFePO4 battery and keep it plugged in and charging.

No switches or any complications.

The only downside I can imagine would be if your power outage ran longer than anticipated and you ran
your batteries down to the point of damage. Maybe you can manage that and/or make the time longer with
larger batteries.
 
MisterSandals said:
The simplest solution I can think of would be to get an LiFePO4 battery large enough to power your
pumps directly for the maximum duration you "could be" without power.
Get an AC powered charger for your LiFePO4 battery and keep it plugged in and charging.

No switches or any complications.

The only downside I can imagine would be if your power outage ran longer than anticipated and you ran
your batteries down to the point of damage. Maybe you can manage that and/or make the time longer with
larger batteries.
Click to expand...

This would work great with an AGM or Gel battery, but LFPs won't last floated at a high voltage like that...
 
MisterSandals said:
Aren't AC chargers smart enough to handle this? I don't know, i only charge with solar, so just asking.
Click to expand...

Good question, but I know the cheap ones don't have that adjustability. Most are pretty dumb, and even say don't charge and supply load at the same time. I'm sure a big RV shore charger would work, but $$$
 
mjoconr said:
So the question for me is if I have a pack which can generate 24 volts what are the following.
1. what is its max voltage ?
2. what is the min voltage ?
3. what voltage would I need to charge / keep the battery charged ?
4. is the max voltage a problem for the pump ?
Click to expand...
It still comes down for me at least I need these questions answered. I'm sure that these will lead to other questions.
 
For a 24v LiFePO4, you can expect a max voltage of 3.65v/cell which is 29.2v if fully charged to the limits.
The max safe discharge bandied about is 2.5v/cell which is 20v if fully discharged to the point of near disaster.
The normal operating range is 3.2v to 3.3v which is 25.6v to 26.4v.
The max voltage that your pump will handle depends upon the pump - it may say on the pump or on the manufacturers literature or documentation.

We are working with your description detailed as "the pump".
 
MisterSandals said:
For a 24v LiFePO4, you can expect a max voltage of 3.65v/cell which is 29.2v if fully charged to the limits.
The max safe discharge bandied about is 2.5v/cell which is 20v if fully discharged to the point of near disaster.
The normal operating range is 3.2v to 3.3v which is 25.6v to 26.4v.
The max voltage that your pump will handle depends upon the pump - it may say on the pump or on the manufacturers literature or documentation.
Click to expand...
So the pump has 24 volts supply, no details are given on its supported voltage range. Its one of these newer generation pumps where it uses DC and a PWM to generate 3 phases which rotate the integrated pump and fixed magnetic rotor.
Do I use a fix voltage power supply to charge the cells ?
Will a BMS disconnect the power at a set max voltage ?
 
mjoconr said:
So the question for me is if I have a pack which can generate 24 volts what are the following.
1. what is its max voltage ?
2. what is the min voltage ?
3. what voltage would I need to charge / keep the battery charged ?
4. is the max voltage a problem for the pump ?
Click to expand...


What is the model # of the pump? To answer those questions we need to look up it's specs, such as:

  • Operation Voltage: DC 12V- 24V
  • PowerConsumption: 5W@12V ~ 21.5W@24V
Which is for this one: https://www.amazon.com/12V-Brushless-Submersible-Fountain-Aquarium/dp/B01IAFCRF2
 
The pumps for the two tanks I want to put a backup on are not sold anymore so I do not have the specs.
There 24V only but not sure on there allowed range. The watts is something i'll need to get a direct reading with a shunt or a meter.
 
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