What is killing all my walmart fridges?

[henboy1]

There's a bunch of what-if's here, bunch of unknowns. Is the inverter running off a dedicated house bank, or off the regular truck batteries? How many? Total amp hours? The compressor kicking on and off can be caused by two things, one is low or no refrigerant (freon), the other is low voltage (which over time will kill the compressor). It may be the inverter, as pure sine wave is better for motors, and that particular motor (in those refrigerators) really wants pure sine and not modified sine. If the inverter is a true sine wave inverter, it'll output a true sine wave whether the truck is running or not.

The fact that the fridge runs better (cools quicker, and colder) when driving, then doesn't stay cool when parked, that one screams low voltage. When the truck is running the alternator is supplying plenty of voltage, which the inverter can piggyback off of, but when parked the batteries must hold that 12.2 volt or higher, and it sounds like when the truck is running the batteries are giving he inverter 12.6 or 12.8 volts (maybe more), but when parked the fridge draws the batteries very quickly down to less than 12 volts, which will cause the compressor to run extremely hot and very inefficiently.

This can be bad batteries (or the wrong kind for this type of application), or it can be battery cables that are too small for the load (or too long between the batteries and the inverter). For a 3000 watt inverter (3000 watts divided by 12 volts = 250 amps), the cables between the inverter and the batteries should be 3 feet max, and AWG 2/0 in size. Even if you never use more than 1500 watts, it would still be 125 amps minimum cabling, so it would need to be 3 feet max and #4 AWG cable, but that still be too small for the nearly constant draw the fridge requires. #2 AWG would really be the absolute minimum to keep the cable from getting too hot. Properly crimped cable lugs is also a hot spot, literally, since an improperly crimped lug causes excessive resistance, and thus increased heat, and a voltage drop to the inverter.

FWIW, I have a 3000 watt pure sine wave inverter that needs repair, for a year and a half now. I'll get around to it eventually. In the meantime I'm using a POS Cobra 1500 watt modified sine wave inverter that I know can't be good for the refrigerator's compressor. I've got a house bank that consists of four 125-amp hour "hybrid" marine batteries (essentially the same as "truck" batteries), and have high dollar Cobra Cable Ultra-Flex cables, 2/0 in size, and even higher dollar Panduit cable lugs. I run a MicroFridge Combination Model 4.8MF-7TP (mine is a little older than the new ones with the "Dual Charging Station", which is two electrical outlets on the front of the microwave) and have had it in the van for a little over 3 years. Over these 3 years it's been unplugged and off power for perhaps a month in total. Still works great. Haven't had to change the temperature setting, freezer is till frost-free and it keeps ice cream frozen hard. It is sitting on top of a some carpet with a heavy carpet pad underneath, and it's bolted to the wall. It ain't movin'.

Batteries

MicroFridge

Turtle, my battery setup in the semi looks just like that.I think my uncle said it's a para series setup and I also had 4 blue top OPTIMA, and one generic I purchased from O reily a year ago.I went to the truck today after buying a MULTIMETER from walmart.
These are the results.
UNDER LOAD AND TRUCK IS IDLING(fridge,printer/scanner,tv and signal amplifier is all on)
checked measurment at surge protector for output voltage.
1.input-13.48/13.49Volts(truck was not fully warmed)
2.Output-106.7volts/107volts


Bumping the idle around 1400rpm made no changes in input and output voltages.


NO LOAD TEST AT BOTH THE POWER INVERTER'S(NO SURGE PROTECTOR CONNECTED)INPUT AND OUTPUT.
INPUT-13.5volts
OUTPUT-107.2VOLTS/107.3VOLTS


The volts are pretty consistent but why the heck am I only getting 107Volts at the output?

Turtle, my battery cables going into the sleeper looks a bit thicker than what you have going to the inverter.I forgot to check for the AWG measurements.
I also made some few changes, I replaced the generic Oreilly battery with another Optima battery.I also replaced the Surge Protector with a much bigger one.This last fridge do not have a freezer compartment and I am not turning the level to the coldest.Just some different changes I have made, if it really makes a difference.Now I am not sure if this inverter is a pure sine wave, but it is a 3000watt inverter.Mind you that my other Vector inverter killed 4 other fridges in about a 2year span.
Your other question about dedicated bank is that, the inverter is running off the truck batteries and nothing dedicated.I am not sure what amp hrs are.

 

[greg334]

That's really low.

Mine is right at 117Vac.

Humor me, go int he house and test the meter by checking the house voltage. I had a few meters that were kind of off to say the least, on AC setting.

 

[henboy1]

That's really low.

Mine is right at 117Vac.

Humor me, go int he house and test the meter by checking the house voltage. I had a few meters that were kind of off to say the least, on AC setting.

I did test the meter with my portable generator on the truck and I did recieve 116volts from the terminals.Can low voltage on the output of an inverter cause these killings?

 

[Turtle]

Turtle, my battery setup in the semi looks just like that.I think my uncle said it's a para series setup and I also had 4 blue top OPTIMA, and one generic I purchased from O reily a year ago.

OK, first, Optima batteries are a type of AGM battery, and a generic almost certainly isn't. It's a way bad idea to mix AGM and wet batteries in the same setup, mainly because they each require different charging parameters, and they will discharge at different rates. It's best to use the same type, and brand of batteries when they are hooked together. It's also best to buy all the batteries at the same time, and replace all of them at the same time. Hooked together, all of the batteries become essentially one great big battery. So, you want all of them to be the same kind, brand, age, everything.

I went to the truck today after buying a MULTIMETER from walmart.
These are the results.
UNDER LOAD AND TRUCK IS IDLING(fridge,printer/scanner,tv and signal amplifier is all on)
checked measurment at surge protector for output voltage.
1.input-13.48/13.49Volts(truck was not fully warmed)
2.Output-106.7volts/107volts

As Greg said, that's a little low. Should be 110-125 or thereabouts. Your inverter may be a 110 volt inverter, and if it is, then the voltage should be between 110-120. 106 volts is low. Over long periods of time, it's enough to burn out induction motors of the kind in air conditioners, refrigerators and microwaves.


[/quote]Bumping the idle around 1400rpm made no changes in input and output voltages.

NO LOAD TEST AT BOTH THE POWER INVERTER'S(NO SURGE PROTECTOR CONNECTED)INPUT AND OUTPUT.
INPUT-13.5volts
OUTPUT-107.2VOLTS/107.3VOLTS


The volts are pretty consistent but why the heck am I only getting 107Volts at the output?[/quote]

I dunno. I'm guessing a crappy inverter. There's a lot of them out there.

What are the voltages when the engine is turned off?

Turtle, my battery cables going into the sleeper looks a bit thicker than what you have going to the inverter.I forgot to check for the AWG measurements.

If you notice, my battery cables going into the sleeper looks a bit thicker than what I have going to the inverter, too. The one running into the sleeper (from the alternator) is the one that looks like it's coming from nowhere at the lower right of the picture, then connects to a big Class T fuse that you can't see because of the glare, and then has a short run to the main positive bus bar. The cable going into the sleeper, and all the interconnects, at 2/0 cable. The inverter is a 1500 watt inverter, which required #2 AWG cable, which is what I'm using.

I also made some few changes, I replaced the generic Oreilly battery with another Optima battery.I also replaced the Surge Protector with a much bigger one.This last fridge do not have a freezer compartment and I am not turning the level to the coldest.Just some different changes I have made, if it really makes a difference.

Well, it's good that you replaced the generic with the same type of battery as the other Optimas. As for surge protection, power surges and spikes generally aren't a problem with inverters, as inverters have those protections already built it. A surge protector in a truck is more for the convenience of a power strips than anything. No need to spend $100 on a surge protector for the truck.

Now I am not sure if this inverter is a pure sine wave, but it is a 3000watt inverter.

I'm willing to bet that if it was a pure sine wave inverter, you'd know it without any question at all. The ones from Aims are relatively cheap, about $900 for a pure sine wave at 3000 watts. Other brands of pure sine waves are 2-3 times that, i.e., Samlex is $1600, Xantrex is $2200, and the cream of the crop Outback Power is $2800.

Mind you that my other Vector inverter killed 4 other fridges in about a 2year span.

Vector, like my Cobra, is crap. But for most loads those kinds of inverters do fine.

Pure sine wave is far better conditioned electricity and is more pure than house current. And that's what you want for the type of induction motors found on electric fans and compressors, as well as sensitive electronics. Pure sine wave lets motors run cooler, cleaner and quieter, and as a result, far more efficiently than modified sine wave electricity. The clock on a microwave will not keep the correct time when plugged into a modified sine wave inverter. It's because the clock uses the regular pulses of a sine wave to time the clock, and modified sine wave doesn't have that. The clock on my microwave runs 1 hour fast per every 24 hours. All other electrical stuff is similarly affected, where they work harder than they should, because the wave of electricity isn't what they expect.

I do have a relatively high end compressor in this fridge, and it's designed specifically for old apartments and dorm rooms where the voltage might be iffy. I think that's the only reason that the modified sine wave inverter that I've been using for all this time hasn't killed it dead. (I really need to get that sine wave inverter repaired or replaced. Sheesh.)

Your other question about dedicated bank is that, the inverter is running off the truck batteries and nothing dedicated.

OK. It is better to have starting batteries for starting and running the truck, and then an isolated house bank for the house. That's not always practical in a truck, I know, so at minimum you really should have some kind of monitoring system to monitor the voltage of the batteries to make sure you don't run them down too low while parked. Best if it also monitors the amp hours (amps per hour) that get used, as well as those that get put back into the batteries (like the one from Xantrex). But at the very least a monitor that will monitor the voltage to alert you when the battery voltage gets below 12 volts (not 11.2 volts to where the lights dim, fans run slower and the inverter finally starts screaming when it falls to 10.8 volts). When the batteries fall below 12 volts, you can then at least crank the truck or the generator to recharge batteries.

I am not sure what amp hrs are.

Amp hours is the capacity of the battery in amps her hour. Most batteries are rated at the 20 hour rate. The Amp Hour rating tells you how much amperage is available when discharged at a constant rate over a 20 hour period. In order to know how many constant amps the battery will output for 20 hours, you have to divide the amp hour rating by 20. So, if a battery has an amp hour rating of 75 (like the blue top Optimas are), dividing by 20 = 3.75. Which means, a blue top Optima battery can carry a 3.75 amp load for 20 hours before dropping to 10.5 volts. (10.5 volts is the fully discharged level, at which point the battery needs to be recharged, but 12 volts is the 50% Depth of Discharge (DoD) level, a level that you should never go below.)

If you have 5 identical blue tops, then 5 times 75 gives you 375 amp hours of capacity (assuming brand new batteries that haven't yet lost any of their capacity, which all batteries will lose over time). 375 amp hours divided by 2 to get the 50% DoD level is 187.5 amp hours before you need to fully recharge the batteries (running the engine for 15 minutes to recharge them won't do it).

If your fridge is pulling, say, 2 amps AC at 110 volts off the inverter, then that's 20-22 amps off the batteries. Let's call it 22 to take into account the 10% or so lost to the inverter. At 22 amps from a 375 amp hour battery, that'll give you roughly 16 hours before the battery is dead, 8 hours before the battery reaches the 50% DoD mark and you need to recharge.

Now, with the engine turned off and the inverter on and the fridge running, what's the volts on the batteries? If it's anything less than 12 volts, then the batteries are bad and need to be replaced. If it's more than 12.2 volts, then it's the inverter that's not putting out the proper voltage. Or, it could be just as simple as the compressors in the refrigerators you keep buying do not like a modified sine wave and will run perfectly fine with a pure sine wave inverter.

For a few lights, a computer and a few other doodads, modified sine save is fine. But for everything else, pure sine wave is better. Electronics and motors will, absolutely, last longer and run better on pure sine wave. You just have to decide on the higher cost of a pure sine wave. I have that 3000 watt Aims that a nut came lose inside the box, rattled around and caused a short and it fried bit time. Smelled real nice in the van for weeks. But for nearly 2 years I've been using a quick and easy replacement in the Cobra 1500 watt inverter.

Check the voltage when the engine is off. Check the cabling. If everything checks out electronically, I'd get a pure sine wave. You almost certainly don't need 3000 watts, tho. 1500 watts should be fine, unless you're got a high wattage microwave, then 2000 watts should do it. I have that 3000 watt, but got it because it was on sale and at the time I was using a corded power saw and a few other tools out in a field with it, so I needed it at the time. Now it's overkill. I need to replace this one, but getting the 3000 watt inverter repaired is almost certainly going to be more than just buying a new 1500 watt pure sine save in the $429 range (Aims). But in all honesty, a modified sine wave inverter should run a small refrigerator just fine, so in your case I really don't think it's a pure sine versus modified sine problem. I think it's either the batteries, or you have a crappy inverter.

 

[Turtle]

I did test the meter with my portable generator on the truck and I did recieve 116volts from the terminals.Can low voltage on the output of an inverter cause these killings?

Absolutely. If you look at my original reply, you'll see where it says:

The compressor kicking on and off can be caused by two things, one is low or no refrigerant (freon), the other is low voltage (which over time will kill the compressor).

Borrow another inverter and check it out. Borrow a good one.

 

[henboy1]

OK, first, Optima batteries are a type of I think it's either the batteries, or you have a crappy inverter.

I think I have narrowed down my problem.
I went back to the truck this morning.The output voltage while the truck is off was 110volts most of the times but when idling, I was getting the usual 107/106.9 volts.
With no load, I am still getting 110v(truck not idling) and it only drops 1volt when the fridge is turned on.I believe 110 volts is even too low.
THE QUESTION IS , WHAT KILLED BOTH INVERTERS?
This inverter is not even 3000watt as I thought but rather a 1500watt ROAD PORO RPPI-1500 watt with 3000watt peak.

History behind this problem:
As I mentioned above, I went through 3-4 fridges with the 1000watt Vector I had.On my last fridge the fan inside the inverter was not coming on whenever I used high wattage items like the microwave.Previously, anytime I used the microwave, the internal inverter fan would be humming at it's highest peak.After using the micrawave to heat (the truck is always running and the cruise is bumped at around a 1100rpms)up certain frozen items,a good amount of heat will build up around the casing.If I am right , micrawaves run at around 1500 watts and 10 minutes of running a micrawave almost everyday on a 1000watt vector or 1500 Road Pro is too much.As the Vector fan stopped humming, the inverter would heat up soo much and just beep and cut off until it cooled down.The vector still works, but did you know I was only getting 97-103volts at it's output today?
To make a long story short, the inverter is the culprit but what kills it is the microwave.
I then tested a 400 watt inverter that I had stashed under the bunk and that gave me a consistent 120volts.
To fix this problem I will need to either buy another inverter and never use it on the microwave or get a DC/AC converter to use it directly on the batteries(cigarette lighter plug).The microwave is now plugged into the generator and not the inverter.
I hope my findings are right.

 

[greg334]

These are the specs I found for that inverter

RPPI-1500W

Operating Voltage 10 - 15 Volts DC

No Load Voltage: 109.25 - 120.75 Volts AC,

AC Output: 109.25 - 120.75 Volts AC

AC Output Frequency: 58Hz - 62Hz

Efficiency (Maximum): 87%

 

[henboy1]

These are the specs I found for that inverter

Greg, are you saying my readings are normal, and just not meant for a fridge?

 

[greg334]

Yep it looks like the problem is the application of the inverter.

 

[Turtle]

Check the microwave for how many watts it consumes. Microwave "cooking" power in watts is not the same as the wattage draw. There should be a label on the back of the microwave that tells either watts or amps, but they usually say watts.

On my Microfridge, because it is specifically designed for old apartments and dorm rooms that may have old substandard wiring, it is set up so that no matter what, it will never draw more than 10 amps at 110v AC. You plug the fridge part into an outlet on the rear of the microwave, and then you plug the microwave into the power outlet at the wall (or the inverter). When you start the microwave, it automatically cuts all power to the fridge/freezer part to ensure that no more than 10 amps get pulled. You could have a situation where the microwave is running and then the fridge's compressor decides to kick in, and the initial amps it takes to start the motor might be 20 or 30 amps, for a second or two, and that on top of the wattage the microwave is already pulling can really tax an inverter.

The microwave is not a full-sized, full-power microwave. It's a 900 watt microwave, so it draws less power (so it takes a lot longer than the cooking directions on the side of the food packages state). But if the microwave is running and pulling 10 amps and the fridge is running and pulling, say, 3 amps, and anything else you have running is also pulling amps, then you're at or near, or beyond, the "sustained" wattage of the inverter.

The inverter may be a 1500 watt inverter (12.5 amps), and that 3000 watt "peak" (25 amps) is for things like the initial whoomp of the compressor motor, which can be 20-30 amps. But it's almost certainly not rated for 1500 watts continuously. It's probably 1500 watts for a maximum of 5 minutes, and it's actually about 1250 watts for sustained draws of more than 5 minutes.

Also, it's efficiency at 87% max is pretty bad (my broken inverter is 86%, which is also pretty bad ). Most of the time yours probably between 80% and 85%. The standard for efficiency is at least 90% for full load, and 95% for half load or less.

If you have a 10 amp draw, you have to add 10% to that to take into account for the inverter loss due to it only being 90% efficient. So a 10 amp draw becomes an 11 amp draw. In the case of the RoadPro, it's more like 15% (or more), so that 10 amp draw becomes 11.5 amps. More to the point, a 12.5 amp draw at 1500 watts actually becomes a 14.375 amp draw, which is enough over time to severely weaken and kill an inverter, causing it to output too low a voltage on a regular basis.

Without knowing for sure how many watts your microwave draws, it sounds like you need a 2000 watt inverter. You can get an Aims pure sine wave inverter for less than $500 in the 2000 watt range. That would eliminate the problem of drawing too many watts, as well as give you pure sine wave that eliminates a whole lot of potential problems. Many (if not the vast majority) of refrigerators will run on a modified sine wave inverter, but there is no question that a pure sine wave will be better for everything connected to it. But if you would rather go cheaper with a modified sine wave, I'd highly recommend staying away from all of the truck stop inverters except the Cobra (while it's still crap, it's at least semi-well-made crap). Better is something like one by Tripp-Lite, who make state of the art inverters and surge protectors (ISOBAR).

If I were to buy a 2000 watt modified sine wave inverter today, I'd get the Trip-Lite PV2000FC, which is a 120 VAC output 2000 watt continuous inverter, with a 3000 watt output for one hour, and 4000 watts for 10 seconds (to start fridge compressor motors and stuff like the initial hit of a microwave induction motor). It's a heavy duty inverter designed for the bumps of the road. . Amazon has that for only $380, which is a really good price. There is also the PV2400FC which is a heavy duty 2400 watt inverter for about $450 at Amazon).

A lighter duty inverter is the PV1800HF (1800 watts for about $250 at Amazon), or the PV3000HF (3000 watts for about $425 at Amazon).

What I have that is broken and needs to be fixed or replaced is the Aims 3000 watt pure sine wave inverter (I think I paid about $900 for it, maybe $950). I think it's going to cost about $500 to repair, so I'll probably just replace it with either a 1500 or 2000 watt pure sine wave from Aims which will be $430 or $600 depending.

 

[aristotle]

Am I the only dinosaur still using an ice chest/Coleman cooler? It's primitive, practical and frugal.

 

[Turtle]

If all you need electricity for is to power a fridge, and don't do computers or lights and fans and a bunch of other stuff, then batteries would be expensive overkill. If all you need is to keep something cold, then those thermostatic coolers that run off the 12v volt cigarette lighter is fine. I have worn out a few Igloo Koomate coolers in my day. If all you need is something like one of those coolers and have otherwise minimal electrical needs, like maybe a laptop and a few other small things, an Espar heater, then just one aux battery should be fine.

I got the one I have because it's larger and can hold a week's worth of groceries, and it's got a frost-free freezer that actually keeps stuff frozen.

I don't know if I'd want to mess with an unpowered cooler and have to keep filling the thing with ice all the time, tho.

 

[are12]

Henboy1,

By any chance, do you shut your fridge down when you are home?

We would go through a fridge a year and could not figure out what the problem was. While we were at Camper World, Jim was talking with the owner and telling him how he could not understand why the fridge would die within a year, when it was not used while we were at home. That is when the owner told Jim that refrigerator's are not meant to be turned on and off and that is what was probably killing our fridge. He told Jim, just leave a couple of bottles of water in it and turn it way down, while we were at home. Since then, we have not had to replace our fridge for over 2 years now.

It may not be your problem but I thought I would throw it out there.

 

[henboy1]

Henboy1,

By any chance, do you shut your fridge down when you are home?

We would go through a fridge a year and could not figure out what the problem was. While we were at Camper World, Jim was talking with the owner and telling him how he could not understand why the fridge would die within a year, when it was not used while we were at home. That is when the owner told Jim that refrigerator's are not meant to be turned on and off and that is what was probably killing our fridge. He told Jim, just leave a couple of bottles of water in it and turn it way down, while we were at home. Since then, we have not had to replace our fridge for over 2 years now.

It may not be your problem but I thought I would throw it out there.

These are all the accessories plugged into the1500W inverter running off 1000cranking amps blue top OPTIMA batteries.All 4 in par-series and each battery displaying 12.72v volts when not idling.13.5/13.6Volts when idling.
1.Fridge(always turned off at night and after shutting down)
2.TV
3.signal amplifier for TV antenna
4.laptop
5.Fan(not always used)
6.bluetooth charger
7.portable vacum cleaner(truck must be idling to use)
8.3 in 1 flatbed printer/scanner/copier


Portable generator(3500watts)Every item is used independent and not 2 at a time.
1.Portable Ac unit(6000BTU)
2.Mechanics battery charger(10/40/100 amps)
3Microwave(not sure about the starting or running wattage)
4.walmart portable space heater
5.Rice cooker
6.Portable coiled stove

It takes about 24hrs to to completely drain the batteries and have the inverter screaming when the fridge is plugged in and set to it's coldest settings.
Not turning off the fridge may drain my batteries for the next mornings use.

I will take Shells advice and get a true sine wave Inverter and that will soley be for the fridge.At least I am not the only one having this fridge problems.
Hats off to you shell.You know some electronics.
I went to school for that but I don't know as much as you do.
I don't think it justifies buying an RV fridge for $450.
Thank you!

 

[Turtle]

I'll hit the highlights. I notice you use the term "cranking amps". That's a term which is meaningful in only two situations. One, when you are using them to crank the engine. It defines how many amp the battery can punch out very quickly to get the engine turned over, usually for about 10 second. The other time cranking amps means anything is when there is an unfused short where unlike AC current that will smother itself if positive and negative are crossed, DC current will happily pump out every last stinkin' cranking amp, all at once, until the battery is dead. With four 1000 amp cranking batteries connected together, it's effectively a 4000 cranking amp battery in a short-circuit situation, which is enough amps to blow a hole in the bottom of the truck, not to mention enough to make your hair keep on standin' after you're toast. Just something to keep in mind.

As Are12 noted, turning off the fridge at night will dramatically hasten the demise of the fridge. They really and truly are designed to be always on. When I go home for a couple or three of days, my fridge gets plugged into an extension cord from the house. If I'm going to be there for more than a week or so, I'll unplug it, but otherwise it's always on. Generally speaking, for the home, a fridge will be running, that is the compressor will be running, for about 1/3 of the time it's plugged in (depending on how many kids you have and how often the door is open). That's after it's gotten down to temp. In a truck, it will probably be running about 1/2 the time, perhaps a little more, over the course of a 24 hour day, because the ambient temperature in the truck will vary a great deal more than in the home. But, if you unplug it at night, then not only is the compressor running at full tilt boogie nearly all the time it's plugged in trying to get the thing cooled down, when it's unplugged there's no electricity to allow the fridge to do some internal housekeeping like circulating the freon and dealing with condensation at various places in the system. For example, those coils on the back of the fridge are sometimes hot, sometimes cool, and they don't necessarily coincide with whether or not the compressor is running. It takes several cycles, usually over a 24-48 hour period before the compressor and other things get settled in to where it will work efficiently. If you interrupt that by unplugging it every night, when you do plug it back in the entire system has to work much harder to get back to where it can even begin the cycle again.

Find the appropriate thermostat setting, not coldest, that's for sure, and set it there, and leave it set there, and leave the fridge running all the time. Another way to quickly kill a fridge it to play with the thermostat setting. It's not just a simple on/off thermostat. The colder you set it the harder the system has to work to do all those housekeeping things. Setting it to the coldest when you plug it back in will certainly get it colder quicker, but it's also making everything about it work much harder than it has to, and will relatively quickly kill it (as you have perhaps noticed).

"It takes about 24hrs to to completely drain the batteries and have the inverter screaming when the fridge is plugged in and set to it's coldest settings."

The deeper you discharge a battery the shorter the battery life will be. The farther down below 50% you go the faster that will happen. If you routinely drain AGM batteries down to where the inverter screams, then you are rapidly turning 6 or 7 year batteries into 2 year batteries.

"Not turning off the fridge may drain my batteries for the next mornings use."

Which is why it's not a good idea to run inverters off your cranking batteries. Use the cranking batteries to crank the truck, and to run the truck's electrical systems, and then have a separate, totally isolated house bank of batteries for inverter use.

I would not recommend running a 120 volt refrigerator, or anything else that requires a relative high amp draw over extended periods, off of your truck's cranking batteries. Truckers do it all the time, and then wonder why their refrigerator or their batteries won't last as long as they are supposed to. If you're going to run all that mess off your cranking batteries, then at the very least you need to be totally and completely happy with an Igloo Koolmate cooler for you fridge. It's cheaper than a fridge, it'll keep things cool, you can leave it running 24/7, and it's got a low amp draw that won't kill your batteries.

Another option is to keep the fridge plugged in always and at the times you'd normally unplug it, that's when you fire up the generator to power the fridge and recharge the batteries. If I had a generator, that would be the no-brainer option, as that would ensure your cranking batteries are never discharged below 50%.

Third option is to get 4 more batteries as a house bank and use them for the house stuff, keeping the house bank and the cranking bank totally separate. You can then keep the fridge plugged in all the time, and still use the alternator to recharge batteries when driving, and the generator to recharge them when sitting. This is the best, most cost efficient and energy efficient option, actually.

Getting the true sine wave inverter is a good thing, since pure sine wave is always better than a modified sine wave. But none of that will matter unless you reconcile the unplugging of the fridge and the battery bank problem.

"Hats off to you shell.You know some electronics."

Thanks. Actually, electronics in general I'm pretty stupid with. For example, I have no idea how and inverter works. Not a clue.

But I know my batteries. I know how they work and what makes them tick, what's good and what's bad for them.

 

[layoutshooter]

Oh Great Shelled One, has it ever occured to you that you might be able to make a WHOLE lot more money designing and installing battery systems for expediters than you make expediting? I am willing to bet that there is a market for your skills out there.

 

[Doggie Daddy]

Am I the only dinosaur still using an ice chest/Coleman cooler? It's primitive, practical and frugal.

You are not being frugal if you are paying for ice every day only to have it melt away.

As for paying for ice everyday,where do these t/s get off charging what they do for a bag of ice? Captive audience?

 

[Turtle]

On the big sign at the J here in beautiful downtown Ft Pierce, "Powerade - 2 for $4"
Like that's a good deal. They are 2 for $3 at Pilot, and 97 cents a pop at the grocery store. Walmart had 'em for 3 for $2 the other day in SC. Powerade Zero, same price, of course.

I bring this up because you can fill your fridge with Powerade (or Gatorade) and always be all electrolyted up.

 

[layoutshooter]

Electrolytes are good for your batteries!!!