Ecotech battery backup-- multiple batteries question

[TheReeferer]

I've 2 of the Ecotech battery backups that according to the manual you can daisy chain them to double the run time.
These are simple units with a lead acid battery. It does not have electronic controller what so ever... see picture.

My question is can I just use one charger and it will charge both batteries or do I need both chargers plugged into each battery? The ecotech rep told me I need both, also manual indicates both. However, look at how these units are wired, it's simple series wiring, I think it means I CAN use just one charger to keep both charged. See pic.
Can someone please confirm?

(not my pic, but my unit is exactly the same inside)

 

[cdemoss01]

Always be careful with electrical units. If it were me I'd just go with two chargers.

 

[n2585722]

I've 2 of the Ecotech battery backups that according to the manual you can daisy chain them to double the run time.
These are simple units with a lead acid battery. It does not have electronic controller what so ever... see picture.

My question is can I just use one charger and it will charge both batteries or do I need both chargers plugged into each battery? The ecotech rep told me I need both, also manual indicates both. However, look at how these units are wired, it's simple series wiring, I think it means I CAN use just one charger to keep both charged. See pic.
Can someone please confirm?

(not my pic, but my unit is exactly the same inside)

They cannot be wired in series since that would double your voltage output. It has to be parallel wiring. to keep the same voltage on batteries. ai only have the one EcoTech backup but I also only have 2 MP10's and their flow rate is set to 6% when on battery backup. Several years ago We had rolling blackouts that lasted a week. Whatever the off time was the power was on the same amount of time which was 50% on and 50% off. The minimum off time was one hour and on some days it was off 4 hours at a time. The MP10's ran the whole time during the off times without any issues. My return pump which is AC on the other hand was off during the off times and so was my heaters in the tank and the house. The outside temp that whole week was below 32 degrees so the tank did get to just under 70 degrees and took 2 days to get back up to 76 degrees. I did not loose any corals or fish during the event.

 

[Brian916]

On topic...you theoretically should be able to wire those batteries in parallel and double your storage capacity, but you will also increase the available amperage. This may or may not be a problem for your pump. Given the complete lack of safety charge/discharge circuitry in that backup, I wouldn't risk my powerhead (or a fire) by modifying this thing.


Slightly off-topic rant aimed at the industry and not OP (you bought one of the few products available out of best intentions)...

For the price, I was shocked at how little EcoTech put into that battery system!!! If your picture is correct, then there is no charge/discharge control circuit or attempt at a battery tender? This is a $30 battery (retail), a few wires, a plastic box, and a sticker. It cost them probably less than $10 to manufacture and probably another $10 to market and distribute. Maybe EcoTech stickers are worth $180, but it sure won't save my tank when the power goes out.

I have added a photo of the inside of my IceCap battery backup. You can see the circuit that theoretically works as a charge controller for the battery, regulates the output amperage, and auto switches to backup when the power goes out. I expected the EcoTech to be a more sophisticated system that would be better at maintaining the battery or perhaps extending the run-time... I guess not.

For my money, the IceCap is a better built system, but also deficient. A few features that we need are:

- A UPS that is purpose built for 12v and 24v DC aquarium pumps.

-Better battery cells. IME the small cheap Pb AGM style batteries rapidly degrade to the point where it will not supply sufficient voltage to run a powerhead. I just tested mine and it is putting out 8v and needs to be replaced again after 1 year.

- Better battery tending features. A battery tender/trickle charge system is super common for storing automotive batteries. If LiPo bateries are used the system should have smart battery management like most modern phones to avoid overcharge and deep discharge.

- The UPS should have a self test feature to alert you proactively when the cells are degraded and will not power your equipment. If the battery won't deliver ~12v at 1 amp then it won't run my MP10. I shouldn't have to test this monthly.

For $215 for the EcoTech battery (or $195 for IceCap), we ought to be getting a lot more for the money. We need to demand better backup systems. Power outages claim tanks every year driving people out of the hobby. Backup batteries can keep vital equipment running until you can get a generator or bigger battery setup.