Battery backup

Motivations and inspiration

Keeping some fishes quite special, complicated to get or even expensive, you'll always be looking for the best life support system for them. Such setup will be often an high teck tank with filter, UV, heater, air pump and other dosing pump.
One situation, bit stressful but hopefully quite rare, is what's going in case of power outage?

Different options:

• Equipment directly on battery, e.g. air pump

• UPS (uninterruptible power source) or inverter for the complete system

• Some extra battery e.g. EcoTech Marine VorTech Battery Backup

• …. or a DIY budget friendly version of such battery as I do have in my sump a DC pump (Aqua Medic DC runner 5.3), I'll give a try to it!

As usual, to do your research before to start is part of the project. I would suggest a video from Australian Youtuber Parkers Reef on this topic, well done!

Checking quickly on Aqua Medic DC runner 5.3, you see:

• 24V -> you'll need a DC boost 12V -> 24V since cost-effective battery are more 12V

• 50W max-> the DC converter need to stand > 2A

So now, let's do bit (sepcialized) shooping!

Equipment

You can do your own custom build based on e.g. 18650 batteries. Keep in mind some consideration and risks as properly mentioned in video of Teaching Tech.
I'll pick this time LiFePO4 batterie with integrated BMS and even a bluetooth connectivity for a remote monitoring of the charge status (prices from 2022.Q3).
Battery directly of 24V exists, but it seems more cost effective to go for a 12V with DC booster module to 24V instead. A DC switch should later do the job between grid or battery power.

• LiFePO4 battery 12,8V 40Ah + charger 8A -> 300€

• DC converter 12V -> 24V 5A 120W with fuse waterproof -> 21€
  (or this one with passive cooling housing -> 25€)

• Battery Controller Automatic Switching Module DC 24V 10A -> 5€

• DC Power Pigtail Cable, 10 Pairs 2A 12V to 24V 22W AWG -> 8€

• (Junction box..)