12 v or invertor?

[probb]

We are having issues with our engine driven compressor fridge. In the interim we are using an engel 40 l fridge freezer that can run on 12v or mains.
My question is are we better to run the engel on 12v through the cigarette lighter connection or on mains power through our inverter? Both are run off a 105 amp/r deep cycle battery.
Hope all this makes sense!

[more]

Originally Posted by probb

We are having issues with our engine driven compressor fridge. In the interim we are using an engel 40 l fridge freezer that can run on 12v or mains.
My question is are we better to run the engel on 12v through the cigarette lighter connection or on mains power through our invertor? Both are run off a 105 amp/r deep cycle battery.
Hope all this makes sense!

Best way is follow manufacture engel frige operational manual.
ask here
https://www.engelaustralia.com.au/en...ridge-freezer/

But is logical use inverter 12v- 220(110 v) maybe 70% efficiency ,fridge is 12V and fridge convert 220(110v) to 12V again maybe 80-90% efficiency.

Logical use Inverter,why easy when can very complicate.
What you think name is cigarette lighter connection.what is purpose cigarette lighter connection. why is not cooled frige connection.

Cigaret lighter is usually under 100W but not continius use,and like on continius use finish in fire.

[smac999]

the 12v will be more efficent then the inverter. espeicly if nothing else needs the inverter. because the inverter can be shut off when not used. it draws power just being on.

[dsteinfeld]

If you believe the manufacturer’s specifications (manual here (https://www.tentworld.com.au/assets/...s/MT-V60FC.pdf) then based on power consumption 12v is the way to go. On 12v, wattage is 12v x 3.1a= 37w, while on 220v (best AC case) it’s 220v x 0.42=92va. So DC wins without even considering power factor and inverter efficiency.

[probb]

Cool. Thank you all.

[mitiempo]

Originally Posted by more

Cigaret lighter is usually under 100W but not continius use,and like on continius use finish in fire.

12 volts is definitely better than using an inverter.

But I wouldn't use the cigarette lighter. I would get the hardwire cord from Engel and wire it appropriately.

[colinalleck]

Ditch the 12v and permanently connect via circuit breaker and appropriately sized wiring
Good luck

[moseriw]

Originally Posted by colinalleck

Ditch the 12v and permanently connect via circuit breaker and appropriately sized wiring
Good luck

Oh yes, just to find out that your inverter is a non sine wave and it won't work? Inverter? I have 2 on board. One 360W and one 1,5kW but I would never run a device on AC when 12VDC is possible. A usual fridge uses 2Ah that makes around 50Ah a day. So why skip the 10-20% loss through the inverter?


I switch my inverter to on when I use the microwave or my line cutter or... And immediadly off when it is done.

[Uncle Bob]

Originally Posted by colinalleck

Ditch the 12v and permanently connect via circuit breaker and appropriately sized wiring
Good luck

I'm guessing that you mean ditch the 12 volt flylead and hardwire with more robust wiring from the 12 volt supply. I would go one step further and include an anderson plug in the line so removal is relatively easy should the need arise.

[Boatyarddog]

Originally Posted by moseriw

Oh yes, just to find out that your inverter is a non sine wave and it won't work? Inverter? I have 2 on board. One 360W and one 1,5kW but I would never run a device on AC when 12VDC is possible. A usual fridge uses 2Ah that makes around 50Ah a day. So why skip the 10-20% loss through the inverter?


I switch my inverter to on when I use the microwave or my line cutter or... And immediadly off when it is done.

I believe all inverters are sine wave, some modified, some true. It's not a problem usually. Electronics need a Cleaner source of power.

A cooling unit need not be compressor run, some use thermal convection, using a heat source to run it as in a propane fridge.

Most types that don't use propane use a heat pile. The 12 vt. Heater used in portable coolers run on the principal that the food just needs a constant temp, and is all ready cooled. Not very good at removing heat, really just keep the food at lower temps.
Compressor run requires more energy, our Hailer refridgerator is just a room fridge, and works fine with a non true sinewave 1000watt inverter. 110 vt.

Charging system on engine keeps up with it under power.
We unplug it when we don't use the engine, keeps cool well.
Or run a 1000watt Honda genset if we want the battery topped up.
Boatyarddog

[MGRodems]

While the 12v direct wired solution makes the most sense for efficient power consumption, our new fridge freezer that was designed to run on either, had difficulty running off 12 volts without shutting itself down (presumably to protect the batteries) even though the 400 AH battery bank was at 100%. It ran fine through the inverter for 50 straight days off grid.

Just a consideration in case you run into the same problem.

[Brewgyver]

Originally Posted by MGRodems

While the 12v direct wired solution makes the most sense for efficient power consumption, our new fridge freezer that was designed to run on either, had difficulty running off 12 volts without shutting itself down (presumably to protect the batteries) even though the 400 AH battery bank was at 100%. It ran fine through the inverter for 50 straight days off grid.

Just a consideration in case you run into the same problem.

If the unit is shutting off on low voltage protection, and your battery bank is even close to full, the likely cause is undersized wiring. Consult the Circuit Wizard on Blue Sea Systems site. Remember that your circuit length is the total length of both conductors, and use the 3% allowable voltage drop option.

[Boatyarddog]

Originally Posted by MGRodems

While the 12v direct wired solution makes the most sense for efficient power consumption, our new fridge freezer that was designed to run on either, had difficulty running off 12 volts without shutting itself down (presumably to protect the batteries) even though the 400 AH battery bank was at 100%. It ran fine through the inverter for 50 straight days off grid.

Just a consideration in case you run into the same problem.

Hard to believe this statement of 50 days, on an inverter run fridge/freezer.

Without any other power. With a 400 amp hr. battery, on inverter pwr.
Even if you never opened it, it cant add up in power use.
It would be 110vts. If it needs a inverter to run.

What's you brand name of cooler, is it stand alone? and inverter?
Boatyarddog

[jamhass]

We ran our Engel for years on 12v while on the boat or in the car. Now, it runs on 120v 'cause we are at home. The refer is quite happy either way. So, IMHO, operating on 12v directly "likely" uses fewer amps than 120v/inverter, so go 12v.

Note "Likely" ... You can certainly test this with care and a decent ammeter. Should it turns out that your Engel uses more actual electrical power from 12v as opposed to 120v/inverter (for very weird reasons, as I believe internally it rectifies 120VAC to 12VDC) then your results may vary.

[jamhass]

Probb:

By the way, we purchased our Engel when our engine-driven refer started to go wonky also. Got us by for a couple more years...

In retrospect, I really wish we had immediately (if not 3 years sooner) replaced the engine driven system with a modern 12v system. Cannot tell you how many engine hours would have been saved, especially as we had (just) enough solar already.