Batteries gone ...

[themexicandoctor]

Next might be an extractor fan at the rear positioned as you said.

[GeorgeRa]

Originally Posted by themexicandoctor

Will present your idea, Thank You.

It appears Heat stvthe back of the fridge isn't an issue, there is plenty off upper air vebting, the critical factor was the fan was positioned too far away from the electronic modukle that it brings air over & extracts up into the very large 37inches x 21inches x 7 inches cavity behind the fridge.

Its very well vented below & has the same size Roadtrek Vents up top.

I moved the Temperature Sensor off the back "skin" of the Chevy body opposite the fridge & placed it against the upper vent baffles, the temperature dropped 12 degrees very quickly.

The other factor, this Heatwave, it feels like Hawwaii right now.

Great to see the progress. What is this apparently electronic module??? I think I asked that question earlier.

[themexicandoctor]

Originally Posted by GeorgeRa

Great to see the progress. What is this apparently electronic module??? I think I asked that question earlier.

I hope this explains the device accurately, will send a photo also


The block, is the electronic module.

This is what The Guru Rod Lambda explained by text when I sent him the photos;



It Looks like the wiring is large enough
Can't quite see what kind of condenser they're using , tho

Now I see
It's a vertical wire and tube
And It does not need any fan at all.*
The fan you see is only to keep air moving over the module.*

When the units running, just put a meter on the 12volts at the module .... it should be around11.8 to 12.3 v dc
And yes the module is where all the wires connect to



They tested the unit with a Clampmeter yesterday, was running 2.1amps.

As it is, nothing blows over the rear of the unit at all, it acts more like an extractor fan, bringing outside air in, across the module & them out & hopefully up.

With all your knowledge, do you think this is a good design?*

I think the issue is simply the volume of air I have available & the distance from the vent, module & fan.

I did on several occasions over the past couple of weeks & the compressor isn't hot at all, the Installer said sometimes these get so hot as to burn your hands

[themexicandoctor]

Here are two photos of the module.

One when the fan was horizontal & one when it was at a 45% angle.

The fan extracts more air & moves it across the module better than when using it in a horizontal fashion.

Its a small fan & so much air to move.

[booster]

Just a few general observations on the airflow to a compressor frig, particularly when vented to the outside with the huge vents installed for a previous absorption unit.


The vents are at least twice as big as they need to be for a gravity only, passive, ventilation system. The big deal is not vent size, IMO, is controlling the airflow to maximize draft in a gravity setup and air looping in a fan forced setup.


Tall, small, chimneys work best as you need the velocity to propel the air out effectively. A big chimney on your fireplace will be constantly backdrafting as the air is not properly handled to generate draft, same with the frig. A relatively small opening at the bottom, but bigger than the top probably, then to a sealed duct to the parts you want to cool. The duct connected to a sealed baffle setup around the cooled parts to the area above them to connect to another duct to the top vent with a sealed connection to the duct. The rest of the area around the ducts and baffles filled with something like fiberglass insulation to insulate from skin heat and prevent any stray airflow.


If you want/need to use a fan to improve performance, you can add it to either the inlet or outlet duct as it won't matter in the sealed setup which won't allow any looping to happen.



With a fan, the setup gets pretty immune to wind conditions or odd airflow from driving at speed, but the gravity system may be affected by either or both.


An alternate to sealing the inlet and outlet to the ductwork is to carefully seal the area between the upper and lower inlets, with the only open area directly over the cooled parts. If you put a fan on a setup like this, however, the fan has to be sealed to the baffle, chimney, areas or you will get looping in the large volume spaces at the inlet and outlet vents. This is how our unit is installed currently, and it works fine, but it is very critical on having the inlet and outlet areas separated from each other except for the desired airpath, which in our case is a sealed duct up to the fan that blows into the compressor and condenser assembled module.


The last method is how most of the internally vented compressor frigs are running, as the cabinet mounting effectively isolates the inlet from outlet if an exhaust fan is used cabinet rear to remove heat from the rear cavity. I do think there is still probably some chance of gravity looping in the rear cavity, but not much because the air comes in under the frig and gets heated and rises to the top of the cabinet before being taken out. The fan inlet and outlet are isolated from each other so the can be no fan forced looping.

[themexicandoctor]

Thank you Booster!

[GeorgeRa]

Originally Posted by themexicandoctor

Here are two photos of the module.

One when the fan was horizontal & one when it was at a 45% angle.

The fan extracts more air & moves it across the module better than when using it in a horizontal fashion.

Its a small fan & so much air to move.

The black rounded cylinder is the Danfoss compressor, it will generate some heat. Attached to it is the Danfoss controller, it should not generate any heat.

As far as I know most of marine compressors fridge keep compressor and condenser together so fan will move air across both. In your case condenser and compressor are separate and fan is blowing air on neither.

[Blazeman]

Just upgraded to 4 Lifeline Group GPL 4CT 6 volt 220ah AGMs, 2 in series., 2 in parallel. Gives me 220 12 volt amp/hrs discharging to 50 %. That’s almost 3 times my original 80 amp/hrs in my 2017 Airstream Interstate

[themexicandoctor]

Originally Posted by Blazeman

Just upgraded to 4 Lifeline Group GPL 4CT 6 volt 220ah AGMs, 2 in series., 2 in parallel. Gives me 220 12 volt amp/hrs discharging to 50 %. That’s almost 3 times my original 80 amp/hrs in my 2017 Airstream Interstate

I dont know if your original ahs are correct but you will love the Lifelines.

Were the other units on there way out?

What sort of Charging Systems do you have & what do you need the most?

[Blazeman]

Originally Posted by themexicandoctor

I dont know if your original ahs are correct but you will love the Lifelines.

Were the other units on there way out? Yes,

What sort of Charging Systems do you have & what do you need the most?

The originals were 2-12 volt lifelines 160 a/h 50%= 80a/h. Left the original Magnum inverter/charger but corrected it to the lifeline reps recommended settings. So far so good, with a whole lot more a/hrs. (Remember AGMs should only be discharged 50%) before recharging, for maximum life. Got my Lifelines from the Battery Guy great people. https://batteryguys.com/

[booster]

Originally Posted by Blazeman

The originals were 2-12 volt lifelines 160 a/h 50%= 80a/h. Left the original Magnum inverter/charger but corrected it to the lifeline reps recommended settings. So far so good, with a whole lot more a/hrs. (Remember AGMs should only be discharged 50%) before recharging, for maximum life. Got my Lifelines from the Battery Guy great people. https://batteryguys.com/

In reference to the 50% discharge "rule". While it is true you get more life at 50% discharge than at 80% discharge, it is nowhere near the "half the life" statement you always see thrown around. You get 50% of the cycles, but those cycles give you 60% more usable power. If you figure as power in and power out of the battery, the net difference is only about 15%. There are several discussions on this forum with all the data and calculations about this. It is an interesting read, you may want to look at them. Of real interest is that the cycles tend to average, so an 80% discharge, would balance out with a 20% discharge cycle and net out the same life as two 50% cycles. Especially for those of us that would only go deep some of the time, hauling a bunch of extra batteries isn't the best option, just to stay above 50%.



50% is also not the point were you get the most cycles as even shallower will give you more recharge cycles. 10% discharge gets lot of cycles, but it would take a lot of batteries to get any capacity that way.


IMO, the tradoff of losing 15% in battery life to get 60% more usable capacity and not have to buy or carry any extra batteries is well worth it.


We have the same batteries as you do and they have been in place for about 5 years and still test new. They have been to 20% without a second thought as long as we get a full charge regularly.


IMO, you are much more likely to shorten battery life from bad charging with less than stellar equipment. There are very few chargers that will always get the batteries full, and never overcharge. This includes nearly all OEM chargers in class b vans. Which Magnum inverter/charger do you have?

[themexicandoctor]

Originally Posted by Blazeman

The originals were 2-12 volt lifelines 160 a/h 50%= 80a/h. Left the original Magnum inverter/charger but corrected it to the lifeline reps recommended settings. So far so good, with a whole lot more a/hrs. (Remember AGMs should only be discharged 50%) before recharging, for maximum life. Got my Lifelines from the Battery Guy great people. https://batteryguys.com/

If you ever need to talk with the Horse's Mouth, call my Mate Andrew Finkelstein in the San Dimas HQs - family member of the family company & knows his stuff - he owns a huge Class C & knows our challenges firsthand - he has been a Godsend to me

[themexicandoctor]

I was just trying to figure out what model 12 volts they were?

I am going to 2 x 6 volt 4GPL 4CTS, I think they are 225ah ÷ 2.

Did you have to modify your battery area?

I chose the 6 volts because the physically fit better.

Mine are leaving the outside rear of the passenger side of the coach & going under the bed.

The Lifelines passed the capacity test perfectly,.

By the way, can I run a 12 vott or two along with the 6 volts? Its an extra 124 lbs of weight.

Just thinking out loud.

[themexicandoctor]

I posted & then saw Booster's explanation

Forget that I asked, I have 2 x perfectly good 12 volts Group 27's if someone needs them for a fraction of the price.

[themexicandoctor]

Some people do focus on amps* per penny & in that sense, lesser batteries make sense.

The retail cost of the Lifeline 27's/100ah is about $350 - thats a lot of money.

However the Peace of Mind that comes from Lifeline AGM Ownership is worth every penny to me ...

Now its just a matter of fine tuning the Victron Meter & Controller & putting the new batteries in under the bed & reconfiguring the set up.

What MAGNUM do you have?

Did Lifeline talk about 13.4 & 14.4 & 15.5 versus 13.3, 14.3 & 15.0?

[Blazeman]

Battery Guy. Shipped free, no taxes in Colorado
Order summary

Lifeline GPL-4CT × 4
$1,359.96
Discount
$-67.99
Subtotal
$1,291.97
Shipping
$0.00
Total
$1,291.97 USD

[Blazeman]

The batteries I replaced were : GPL-24T
https://batteryguys.com/collections/...feline-gpl-24t