12V to 24V Step up battery backup

[Globe182jp]

Hey everyone. I’ve got a technical question for anyone who knows some about electronics.

I am building a battery backup for my IM Nuvo with a Mighty jet. Its a 24V so I will need to use a Step Up converter or two 12V batteries is series.

I want to use one larger lithium battery with a step up Converter to make like easier and cheaper( larger battery, much cheaper lithium 12v Charger compared to a 24V)

I found Converters and they list Amps and watts and I have no idea how to size them for something like my situation.

Pump is about 22w max prob run about 10w and the battery is a 12V LiFePO4 between 18-100Ah largest I can get

Wondering if the Amps on the converters is a limit to the battery size in AH? I know I won’t hit the max Ws but not sure what the A rating is referring to.

Thanks Jake

 

[Reefering1]

The amperage rating on the device is the load capacity. The battery isnt pushing its power through the device, the load pulls it. I would favor the highest rated device. It will run cooler and leave room for future expansion.
That said, I suggest(and did myself) you find a nice high end APC UPS used with bad batteries. I got my APC smart ups 1500 for $60 and connected it to a bank of agm car batteries(@24v). I used 4(about to expand to 8), sounds like you will be fine with 2. Needs to be 24v. The ups will charge and maintain them just fine. That setup will run my entire 180g system(including lights) for about a day, 2.5 days without lighting.

 

[Reefering1]

Agm can be deep discharged safely, lithium- not so much. In a emergency situation I want the option to be able to use ALL the stored power, not just 70-80%, without any safety risks

 

[Globe182jp]

Ok so larger would be better for heat. I actually figured out the pump will be drawing about 8W.

I have to look deeper at AGM batteries, especially if they have small size compared to standard car/truck battery.

I am very limited in space since cabinet (21x14) needs to fit this, other controllers and the ATO reservoir. Need it all contained in one cabinet.

So being able to use one 12V battery is preferred compared to using 2 to get the 24V.