Battery Backup for Neptune Systems DOS pumps

[RayKCMO]

I have a 24v / 100 Ah / 2560 Wh LiFePO4 deep cycle battery that I'm using as battery backup for an Ecotech Marine Vetra M2 return water pump. Neptune Systems DOSing pumps operate at 24v as well. Could I also use this battery to power the DOS pumps during a power outage? Wondering if it requires any special circuitry of can I just the DOS directly to the battery?

 

[theatrus]

Whats the highest voltage the battery at full charge/charging gets?

You can feed it power through a diode-OR bridge easily, just want to make sure its not going to exceed a reasonable voltage level. You'll also need to power up the APEX of course.

 

[RayKCMO]

Whats the highest voltage the battery at full charge/charging gets?

You can feed it power through a diode-OR bridge easily, just want to make sure its not going to exceed a reasonable voltage level. You'll also need to power up the APEX of course.

The 24v battery is rated for 25.6v. My voltage meter show 26.5v when running the Ecotech Marine Vectra M2 pump. I haven't checked the volts when charging. The charger is rated as 24v 10 or 18 amp selectable. I have it set to 10.

Thanks for your help and knowledge here.

 

[theatrus]

The 24v battery is rated for 25.6v. My voltage meter show 26.5v when running the Ecotech Marine Vectra M2 pump. I haven't checked the volts when charging. The charger is rated as 24v 10 or 18 amp selectable. I have it set to 10.

Thanks for your help and knowledge here.

Generally equipment should tolerate +/-20% supply variation and that’s within 10%, so from general engineering practice this seems fine. I can’t vouch for DOS specifics.

The simple way is to use two 40V (or higher) Schottky 2Amp (or higher) diodes - one from the power supply and one from the battery (fused at the wire leaving the battery) feeding the DOS, on the positive voltage wire (connect all the GND wires). This will drop the voltage by about 0.5-0.7V but the DOS doesn’t consume a lot of power so the power lost in the diodes isn’t big. This is a standard “diode-OR” configuration.

You can probably find little boards out there, often as ideal diodes (more efficient), usually marketed for solar stuff but applicable here.

I’m working on integrating batteries into the DCBuddy project I’m working on if you’re looking for something more plug and play.