DIY 24V battery backup

[ConsummatePro]

I was looking for a 24v battery backup to run my Maxspect Jump gyre 4K but couldn’t find one. I tried 12v from a Belkin 12v DC UPS but it didn’t seem to run the gyre reliably towards the end of the charge (the gyre wouldn’t always actually spin). I decided to make my own DIY option.

It’s very easy and outlined in other places, but I thought a picture would help those wanting to make this.

Parts:
1. Tunze safety connector 6105.500 - this will automatically switch from your native DC power supply that come with the pump to the battery backup $65 USD
2. 2xLiFePO 12V 8Ah batteries - I bought this one since it had included patch wires to save me looking for them
$70 CAD each (~$52 USD each)
3. Battery charger capable of 24V and LiFePO compatible () $40 CAD ($30 USD)
Total ~ $200 USD

1. Connect the 2x batteries together in series to get 24v output.
2. Connect the red (+) and black (-) terminals to the Tunze wire harness.
3. Cut off the alligator clips from the battery charger
4. Connect the battery charger wires into the same Tunze wire harness, matching red+black wires
5. Plug the pump’s native AC adapter into the Tunze Safety Connector’s DC input (with AC adapter plugged into the wall outlet as normal).
6. Plug the Tunze’s male DC plug into the circulation pump’s DC input port.
7. Plug the battery charger into the wall.

With this setup, I was able to run my Gyre for about 38 hours in its normal mode with no need to step down the output (I have my Maxspect Gyre 4K set to run in a 30% forward / 50% reverse cycle). I was very happy with the result.

Compared to the $170 USD Icecap backup, I think this is a better option:
- 24V 8 Ah capacity vs 12V 2.5 Ah capacity — I got full normal operation for more than 30 hours.
- 24V output means it works with 24V DC pumps without need for slowing down or a special 12V mode - which many pumps don’t do. Works perfectly with Maxspect Jump Gyre 4K, and tested on my Jebao pumps that refused to even turn on with 12V input.
- If you just need 12V then just buy one battery, save $50 USD.
- easily replace battery size/capacity as needed.
- uses LiFePO batteries which have a much longer life and recharge capacity (claim 10y lifespan, 3000+ charges, lighter weight) vs SLA batteries in premade units.
- downside: it’s ugly and looks like a terrorist bomb kit.
- At least the battery charger gives a visual graphic of battery capacity and charging status.

 

[ConsummatePro]

Not sure why this forum makes Amazon links just show up as big unclickable “a” graphics (at least how it looks on my iPad and Mac).

Battery description is “ECO-WORTHY Lithium Battery 12V 8Ah LiFePO4 Battery 3000+ Deep Cycle Battery with BMS Protection for Kids Ride-On Car, Alarm System, Speaker, Gate Opener, Used as UPS Backup Battery”

and charger name is “10Amp Car Battery Charger, 12V/10A and 24V/5A Lifepo4,Lead-Acid(AGM/Gel/SLA) Automatic Smart Battery Charger,Trickle Charger,”

 

[wcharon]

Thanks for pointing this out. I actually use the Belkin Router Battery Backup which i have 2 of them with 2 Gyres XF-330.

Each battery reducing the power to 30% on both of them at the same time runs about 3 hours. If i have a long time shutdown i have to run to my house after the 3 hours to hook up the other battery or if i am in the house the Portable Generator.

So i will give this a try for the duration time it can run and also i can use the Return Pump which is also 24V Varios 2 RODC 5500.

I am with you that aesthetical will be a problem as i will have to put it in a corner in the Family but maybe i can search for a Battery Box to despite a little.

 

[wcharon]

Well went to put my order thru Amazon and they can't ship these specific items to Puerto Rico.

 

[Daniel@R2R]

This is really cool! Thanks for sharing!!

 

[Harpo]

Thanks, great info

 

[rgulrich]

Built a couple - they work great! With the addition of a couple of jacks I put mine into a couple of project boxes to keep things tidy, and I keep the chargers on top for status monitoring. One is used for a 24V return pump and it handles the load quite well (fully ops checked during a recent thunderstorm power outage). I may end up adding another battery pack (of two batteries) to this one to extend the run time. The other is connected to a 24V circulation pump as a "backup backup" for maintaining water circulation in the system if all else fails.
Thanks again for a great solution!
Cheers,
Ray

 

[apb03]

I'd add a DC fuse panel to this build. Will provide safety and you can scale to more devices. You can do in line fuses as well, but I prefer the panel because it's cleaner and easy to replace the fuses.

 

[rgulrich]

I'd add a DC fuse panel to this build. Will provide safety and you can scale to more devices. You can do in line fuses as well, but I prefer the panel because it's cleaner and easy to replace the fuses.

While I'm not really looking for adding devices to these, where would you recommend tapping in the fuse? The load side of the backup (between the Tunze and the pump)? Or the charger side (between the charger and the batteries/Tunze harness)?
Thanks!
Cheers,
Ray

 

[apb03]

You'll want to place the fuse where the load comes from the battery to the Tunze. That way if you had a short, the battery won't be shorted out.

 

[rgulrich]

You'll want to place the fuse where the load comes from the battery to the Tunze. That way if you had a short, the battery won't be shorted out.

Rog - thanks!
Cheers,
Ray

 

[theatrus]

While I'm not really looking for adding devices to these, where would you recommend tapping in the fuse? The load side of the backup (between the Tunze and the pump)? Or the charger side (between the charger and the batteries/Tunze harness)?
Thanks!
Cheers,
Ray

Remember, the fuse is to protect:
A) The battery
B) The wire

The reason breakers in your house are at the origin of the wiring run is to protect the wires. Hot wires melt things, and eventually cause things to combust. That wire can get very hot before it fails.

The thing with the largest current output potential is the battery.

So, as close to the battery terminals as reasonable is the place for the fuse.

 

[rgulrich]

Remember, the fuse is to protect:
A) The battery
B) The wire

The reason breakers in your house are at the origin of the wiring run is to protect the wires. Hot wires melt things, and eventually cause things to combust. That wire can get very hot before it fails.

The thing with the largest current output potential is the battery.

So, as close to the battery terminals as reasonable is the place for the fuse.

Thanks! I understand the basic concept of a breaker panel - had an education when I purchased a home built in the 70's with a Federal Pacific Electric panel. Had it replaced when the breakers, err, didn't "break" when they should have.
Appreciate the education on the DC circuits.
Cheers,
Ray

 

[Dukereefnz]

I have the same setup with Tunze safety connectors but have 2 x 80Ah batteries setup the same.
Using 4 x Tunze units.
2 are for return pumps on sump
2 are for Tunze streams

I have no - fuse setup so I need to add one.

Just to confirm - add fuse between Tunze safety switchs and positive battery terminal - as close to battery as possible.
What size fuse would you recommend?

Might add another for my Maxspect Gyres... such a great units these Tunze things.

OH - and to add - I had 15 fish - 4 tangs - in a 55G quarantine tank for ICK treatment, and fallow in DT, turned off the power to feed and forgot to turn on the power, went to work. Got home 8hrs later.... no pumps, no heaters, no air stone... nothing. Temp was 19deg, lucky aircon / heat pump was on in my office. I freaked out and turned on the power. No losses - so it does show how long fish can survive. Not recommended. lol

 

[apb03]

I have the same setup with Tunze safety connectors but have 2 x 80Ah batteries setup the same.
Using 4 x Tunze units.
2 are for return pumps on sump
2 are for Tunze streams

I have no - fuse setup so I need to add one.

Just to confirm - add fuse between Tunze safety switchs and positive battery terminal - as close to battery as possible.
What size fuse would you recommend?

Might add another for my Maxspect Gyres... such a great units these Tunze things.

OH - and to add - I had 15 fish - 4 tangs - in a 55G quarantine tank for ICK treatment, and fallow in DT, turned off the power to feed and forgot to turn on the power, went to work. Got home 8hrs later.... no pumps, no heaters, no air stone... nothing. Temp was 19deg, lucky aircon / heat pump was on in my office. I freaked out and turned on the power. No losses - so it does show how long fish can survive. Not recommended. lol

Watts = Volts X Amps is the formula to help you decide on the appropriate fuse. So if you are running a 12v wave pump on a 5amp fuse, you'll be good for about 60 watts. That should work well. I guess you can go down to 2.5watts for 30watts which should be sufficient for a Tunze, I think.

My Ecotech M2 Return Pump running at 80% consumes about 55 watts so a wave maker would be considerably less than that.

 

[theatrus]

I have the same setup with Tunze safety connectors but have 2 x 80Ah batteries setup the same.
Using 4 x Tunze units.
2 are for return pumps on sump
2 are for Tunze streams

I have no - fuse setup so I need to add one.

Just to confirm - add fuse between Tunze safety switchs and positive battery terminal - as close to battery as possible.
What size fuse would you recommend?

Might add another for my Maxspect Gyres... such a great units these Tunze things.

OH - and to add - I had 15 fish - 4 tangs - in a 55G quarantine tank for ICK treatment, and fallow in DT, turned off the power to feed and forgot to turn on the power, went to work. Got home 8hrs later.... no pumps, no heaters, no air stone... nothing. Temp was 19deg, lucky aircon / heat pump was on in my office. I freaked out and turned on the power. No losses - so it does show how long fish can survive. Not recommended. lol

Assume the wire is somewhere around 18-20 gauge? For "chassis wiring" (not building wiring) thats 11-15A or so. Motors starting can consume much higher peak currents (even with DC BLDC motors). You can probably put a 10A fuse in there, and it will do its job to protect against faults. Could go as low as 5A.

Automotive style blade fuses are fine here