LiFePo4 Battery that always powers a DC water pump — Can this work?

TheLoneAquarist

New Member
I’m curious if this type of setup would work: 36ah LiFePo4 battery plugged into a charger that’s charging at 5amps. A 36 volt / 2amp DC pump is always attached to the battery using a small UCTronics DC 12v to 36v boost converter. Thinking that the charger will always be charging at a faster rate than the pump will draw. And if power goes out then there would be no change for the water pump.

Components:
  • Miady 36ah LiFePo4 Battery
  • ExperPower 12V 5A Smart charger
  • UCTronics DC 12V to 36V boost converter
  • Ecotech Marine Vectra M2 Circulation/Return pump
Note: The output for the Ecotech Vectra M2 is 36V and 2.66 amps


Any thoughts would be helpful and keep me thinking. I already have the Miady 36amp hour battery, new.

Best regards and happy sunday!!!
 

snoobler

Solar Honey Badger
No. Charge power is too low.

36V * 2.66A = 95.76W

Your smart charger is only putting out 12V * 5A = 60W. In reality the charger may put out as high as 14.4V * 5A = 72W at full charge, but that's still less than the pump is using.

You can only compare amps at the same voltage. You need at least 3X the amps at 12V as you're using at 36V.

A 10A charger should do it.
 

TheLoneAquarist

New Member
No. Charge power is too low.

36V * 2.66A = 95.76W

Your smart charger is only putting out 12V * 5A = 60W. In reality the charger may put out as high as 14.4V * 5A = 72W at full charge, but that's still less than the pump is using.

You can only compare amps at the same voltage. You need at least 3X the amps at 12V as you're using at 36V.

A 10A charger should do it.
Does this scenario cause any issues with a LiFePo4 battery? Will the battery not last as long if its never fully discharged?
 

TheLoneAquarist

New Member
charger consideration: Victron energy Blue Smart IP65 10amp or 15amp models

Or is this overkill? Is there a more cost effective charger that’s reliable?

Cheers!
 

snoobler

Solar Honey Badger
Love victron, but any cheap 10A 12V battery charger that charges at no more than 14.6V and floats at no more than 13.6V is fine.
 

GSXR1000

Solar Addict
I’m curious if this type of setup would work: 36ah LiFePo4 battery plugged into a charger that’s charging at 5amps. A 36 volt / 2amp DC pump is always attached to the battery using a small UCTronics DC 12v to 36v boost converter. Thinking that the charger will always be charging at a faster rate than the pump will draw. And if power goes out then there would be no change for the water pump.

Components:
  • Miady 36ah LiFePo4 Battery
  • ExperPower 12V 5A Smart charger
  • UCTronics DC 12V to 36V boost converter
  • Ecotech Marine Vectra M2 Circulation/Return pump
Note: The output for the Ecotech Vectra M2 is 36V and 2.66 amps


Any thoughts would be helpful and keep me thinking. I already have the Miady 36amp hour battery, new.

Best regards and happy sunday!!!
your pump will be using 7-8 amps at 12v... so your pump will run for 4 hours of battery is that enough?
 

GSXR1000

Solar Addict
watts=volts x amps
watts= 36v x 2.66A
95.8 watts

95.8 watts= 12v x amps
95.8 watts/12v= amps
8 amps
converter 90% so add another amp

9 amps draw at 12v
 

TheLoneAquarist

New Member
Questions about a LiFePO4 charger for this scenario. I'm looking at the ExpertPower 12V 20A Smart Charger for Lithium LiFePO4 Deep Cycle Rechargeable Batteries on Amazon.

Click here for the link to the product page

  1. Is this charger good for connecting it to the 12V 36Ah Deep Cycle LiFePO4 Battery, 2000 Cycles Miady Rechargeable Battery?
  2. What size wires can I get if I want to change out the alligator clips and replace with eyelits
  3. I was to cut the clips off should install an in line fuse and what rating fuse would be correct?

Thank you,
Isaac
 
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