Powerbank Advice with 12V Output and Passthrough Charging

FoxJump on 08/11/2023 - 16:38
Last edited 08/11/2023 - 16:39

I have a car with a rear cig socket. One which is powered on, only when the car is on.
The car has a big cranking battery that is also suitable for deep discharge (a fancy lithium one)
I have a camping fridge. It needs to keep the food cold.

I am looking for advice for a powerbank that will allow me to
a) plug the fridge to it
b) plug the powerbank into the car
Such that when travelling from A to B, and i stop for a toilet stop, or a grocery shop, it will have enough juice to keep the fridge running for say .. 4hrs. after which point i should be on my way again.
Such that when i'm driving again, the fridge runs and the power bank charges (happy for it to charge slowly/medium speed)
The rear cig socket is limited to 10A
The fridge uses about 1Ah @ 12vish per hour (averaged over 24hrs including night time and in-direct-sunlight at home).
Ive measured it (with a 240v to 12v dc) at home to use 46w at maximum when starting to chill. so let's round this up to 50w)

I dont need a solar panel with a big (expensive) another lithium or SLA battery.
I just want something to keep the food cold while the car is off for a few hours.

Once i arrive at the campsite, I can just clamp the fridge to the car battery directly to get my 12v juice
And the car battery can charge the next day when i go driving again.

Thank you for recommendations.

Electrical & Electronics Power Bank Power Station

Comments

  • pformag on 08/11/2023 - 16:48

    Look at ECOFLOW

    • FoxJump on 08/11/2023 - 16:50

      at $700 .. no thanks.
      i dont need to run the fridge off it for days
      just an hour or two, maybe 4 at worst

      i'm hoping for $300ish

    • FoxJump on 09/11/2023 - 23:04

      okay.. despite a lot of research .. i'm .. leaning .. to ecoflow or bluetti.

      others seem to suck at passthrough charging by either:
      "no" to
      "yes it does it, but not recommended" to
      "once it finishes charging, it cuts off the charging current until it is unplugged and plugged back in"

    • FoxJump on 04/12/2023 - 22:16
      +2

      I ended up with a river2 for $439 by stacking a $100 vendor discount on ebay with a 20% off ebay coupon code.
      for extra power, i've built something to charge the ecoflow from my lawnmower batteries.

      Thanks pformag.

  • geekcohen on 08/11/2023 - 16:55

    You essentially need a dual battery type system that would cover you even when you turn up to camp.

    You don't want to drain your primary battery and be stuck at camp.

    I've done this in my Ute. I didn't go with a fancy lithium for the 2nd battery, just a decent 100AH AGM and it works pretty well. Got an inverter hooked up to it was well with some 12V Cig Sockets as well and recently got a solar blanket for charging it as well when the car isn't running and I am in the same spot for a while.

  • wombat81 on 08/11/2023 - 16:59
    +1

    Running your fridge from your cranking battery, even overnight, is asking for trouble. Even if it's a deep discharge battery.

    What make/model of fridge do you have?

    I don't believe a product exists that does what you want. Something like this will be the closest https://www.bcf.com.au/p/waeco-coolpower-battery-pack-12v-44…

    You could also look at the Makita fridges that run from 18v drill batteries but you'd need an inverter and a Makita charger to charge the batteries while travelling.

    • FoxJump on 08/11/2023 - 17:01

      i thought fridges all had a voltage cut off?
      it's a 60Ah cranking deepcycle lithium battery from itechworld.

      i have a kings 30L escape fridge.

      • geekcohen on 08/11/2023 - 17:22

        So you need to take this into consideration when you looking at batteries and current draw etc.

      • wombat81 on 09/11/2023 - 12:32

        They do usually have a low voltage cut off, but it's to protect the battery from damage and won't ensure you have enough power to to start the car.

        As others have said, a Lithium jump starter might do the job but it won't have the pass through functionality you're after and it may only last an hour or two depending on conditions.

  • GordonD on 08/11/2023 - 18:34

    The car has a big cranking battery that is also suitable for deep discharge (a fancy lithium one)

    That is something I didn't believe exists. You can get a deep discharge lithium iron phosphate batteries. But they are generally not suited to be cranking batteries because they have maximum discharge limits way below what a starter motor needs. The way to get around that is to pair a lithium battery with a supercapacitor pack, so that the battery keeps the supercapacitor pack charged, and the supercapacitor pack cranks the engine when required.

    If someone has manufactured a lithium battery capable of both those uses, well, 60 amp hour isn't that big if you also want to use it to run things like fridges overnight. It isn't big enough to depend on it for starting and runing stuff overnight. I suspect you've made a poor decision to spend a lot of money on a battery claimed to do both things, rather than getting the cranking amps needed with a supercapacitor pack.

    If it really had the equivalent capacity to a 120 amp hour lead acid battery they sell it as a 120 amp hour battery, not a 60 amp hour battery. They're selling it as a 60 amp hour battery because it only has 60 amp hours capacity. Which is enough if all its being used to do is start the car and run the car's accessories while the engine is running.

  • nicktork on 08/11/2023 - 19:28
    +2

    This: https://www.4wdsupacentre.com.au/24ah-lithium-portable-power…

    It will charge from a USB-C adapter in your 12v socket while you're driving and give you several hours of fridge run time when you're parked.

    But don't pay full price. It often goes on sale with a second cheap item at around $250, just wait a few days for the next sale.

    Edit: It's on sale today for $248 including a bluetooth speaker: https://www.4wdsupacentre.com.au/24ah-lithium-portable-power…

    • FoxJump on 08/11/2023 - 20:14

      ah nice!

    • theoscat on 06/03/2024 - 11:48

      have you been using it charing and discharging at the same time and it worked out well?
      tried to look for this piece of info but not avail! thanks mate.

  • brentsbits on 08/11/2023 - 19:34

    Just leave sentry mode on and your Tesla will keep power going to the fridge when you are out of the car. If it's a decent car fridge it won't use much anyway and no power bank is going to compare to your 60kw battery

  • BuyoTheCat on 08/11/2023 - 23:53

    Gooloo jump start powerbanks have a 2.1mm cig socket adaptor. Can power your fridge for a while. Not sure how long. When the car is running you can power the fridge and charge the power bank.

Login or Join to leave a comment
Login Join