Refrigerator and battery issue

[Metoo38411]

I have a new 2021 Transcend xploror and the refrigerator seems to stop working and then works. I’ve had repair people and even GD come and replace the whole fridge. Shortly after the fridge was replaced, the new fridge started doing the same thing, the gd guy told me to get the battery tested and the battery tested bad. The rv os connection to shore power. Fast forward 4 months and again fridge having issues, got the battery tested, came out bad, got it replaced. What could be doing this?

[howson]

I have a new 2021 Transcend xploror and the refrigerator seems to stop working and then works. I’ve had repair people and even GD come and replace the whole fridge. Shortly after the fridge was replaced, the new fridge started doing the same thing, the gd guy told me to get the battery tested and the battery tested bad. The rv os connection to shore power. Fast forward 4 months and again fridge having issues, got the battery tested, came out bad, got it replaced. What could be doing this?

Welcome to Grand Design's (Technical) Owners' Forum. When you get a chance, please check out the Welcome Letter to New Members: https://gdrvowners.com/forum/main-fo...to-new-members

To your question: I'd suspect the battery disconnect switch is getting inadvertently bumped (and turned off) or the converter is faulty.

A converter is used to charge the battery when connected to shore power. Most likely in your Transcend the converter is incorporated into the Power Distribution Panel (PDP), or the "circuit breaker panel". The converter is literally a small circuit board. Research the WFCO website if you can find the model number on the inside cover of your PDP.

Either of these events (inadvertently turning off the battery disconnect or a faulty converter) will keep the battery from charging when connected to shore power.

Howard

[TucsonJim]

Good morning and welcome. It's unusual to have two "new" batteries go bad. Were both batteries the same make and model? I'm wondering if the are from a defective lot.

Another concern is battery storage. If you have a lead acid battery and you allow it to discharge to less than 50% of it's rated amp hour capacity several times, the battery will prematurely die. The battery needs to be completely disconnected from the system anytime it's in storage. The battery disconnect switch will not completely take it out of the circuit and there will be a continuous drain anytime the unit is in storage if all that's done is turn off the disconnect.

Jim

[KrustyKush]

I'm not wanting to hijack this important thread, but it raises a question that may help me learn something. Regarding these lead-acid batteries. Years ago, I was taught that there are "types" of lead-acid batteries. One type, used in automobiles that need a large burst of current to operate a starter motor. Another type, for an application that doesn't involve these large bursts, but rather longer and slower discharge cycles, such as in an RV. I was taught that the starter batteries are the ones that mustn't be allowed to discharge below 50%. But, the other type can be allowed to run down almost to zero charge, and then charged back up without damage.

I have assumed, until now, that the second type of battery is the type we have from the factory in our RVs.

Was I taught wrong? Someone with knowledge can help me here. Thanks.

[Yoda]

I'm not wanting to hijack this important thread, but it raises a question that may help me learn something. Regarding these lead-acid batteries. Years ago, I was taught that there are "types" of lead-acid batteries. One type, used in automobiles that need a large burst of current to operate a starter motor. Another type, for an application that doesn't involve these large bursts, but rather longer and slower discharge cycles, such as in an RV. I was taught that the starter batteries are the ones that mustn't be allowed to discharge below 50%. But, the other type can be allowed to run down almost to zero charge, and then charged back up without damage.

I have assumed, until now, that the second type of battery is the type we have from the factory in our RVs.

Was I taught wrong? Someone with knowledge can help me here. Thanks.

All flooded lead acid battery's should not be discharged below 50% SOC (state of charge) Which I think is 12.2V Chart https://www.mmbalmainauto.com.au/PDF..._batteries.pdf

I believe you are referring to a car starter battery, usually rated in CCA (cold cranking amps) and a deep cycle battery rated in AH (Amp Hours), GD does not install the batterys at the factory. They are installed by the dealer and are usually the cheapest they can find. Your dealer should have provided a deep cycle between 100 and 200 ah. Again any flooded lead acid battery should not be discharged below %50.

I have a bank of 4 -6V Crown CR260 (260ah each) deep cycle batterys (GC2 golf cart models) wired in series/parallel to give me 12V and 520 AH capacity, but only 260ah is usable.

Now there are other batterys to consider such as AGM which I believe have a better discharge profile and then there are the premium LiFePO4 batterys, but to get full capacity you may need a special charger/converter. LiFePO4 batterys can be discharged to near zero SOC.

There is a battery thread here someplace in the resource section. Battery 101 I believe is the title.

Merry Christmas
Keith

[Scott.n.Tira]

I have a new 2021 Transcend xploror and the refrigerator seems to stop working and then works. I’ve had repair people and even GD come and replace the whole fridge. Shortly after the fridge was replaced, the new fridge started doing the same thing, the gd guy told me to get the battery tested and the battery tested bad. The rv os connection to shore power. Fast forward 4 months and again fridge having issues, got the battery tested, came out bad, got it replaced. What could be doing this?

Hi,

I suspect Howson is on the right track as usual, my thought was the same... if your battery is not being charged while on shore power, that sounds like a charger (converter) problem. It may be bad, but it may be turned off as well, I would suggest starting at the fuses and make sure it's turned on.
A simple test would be to check your battery voltage with the Trailer unplugged from shore power, then plug it in and see if your voltage goes up. If it doesn't, then the converter is not on or is not working.

Good luck, let us know?

[Jkwilson]

I'm not wanting to hijack this important thread, but it raises a question that may help me learn something. Regarding these lead-acid batteries. Years ago, I was taught that there are "types" of lead-acid batteries. One type, used in automobiles that need a large burst of current to operate a starter motor. Another type, for an application that doesn't involve these large bursts, but rather longer and slower discharge cycles, such as in an RV. I was taught that the starter batteries are the ones that mustn't be allowed to discharge below 50%. But, the other type can be allowed to run down almost to zero charge, and then charged back up without damage.

I have assumed, until now, that the second type of battery is the type we have from the factory in our RVs.

Was I taught wrong? Someone with knowledge can help me here. Thanks.

You are correct, but you’ll never convince people. So many people incorrectly believe the 50% myth that it will never be refuted, even with all of the facts in the world.

[Scott.n.Tira]

You are correct, but you’ll never convince people. So many people incorrectly believe the 50% myth that it will never be refuted, even with all of the facts in the world.

What myth are you referring to here....are you saying some of us can't be convinced that there are different types of batteries, or that RV deep cycle batteries should be discharged below 50%?

[AZMike]

You are correct, but you’ll never convince people. So many people incorrectly believe the 50% myth that it will never be refuted, even with all of the facts in the world.

I would also like to know what this "myth" is.

[Jkwilson]

What myth are you referring to here....are you saying some of us can't be convinced that there are different types of batteries, or that RV deep cycle batteries should be discharged below 50%?

That RV batteries can’t be discharged below 50% or they will be damaged.

Here’s a typical graph from Concord showing how lead-acid cycle life varies with average depth of discharge. If there was any special danger in discharging below 50%, there would be a steepening of the slope somewhere to the right of 50%, but on the contrary, the slope actually declines. Don’t let your eye get fooled, since this graph is a log scale. On a linear scale the curve below about 30% would be close to flat.

You can see from this chart that an average 20% DoD costs 2000 cycles compared to a 10% DoD, 30% average DoD costs you 1000 cycles more than 20%, 40% average DoD costs you about 500 cycles more than 30%, 50% average DoD costs you about 400 more cycles than 40%, 60% average DoD costs you about 200 cycles compared to 50%, 70% average DoD costs you about 120 more cycles than 60% DoD, 80%, 90% and 100% average DoD each costs you about 120 more cycles than the previous percentage.

The vast majority, 80%, of the cycle life consumed is above 50% average DoD. 60% of the life consumed is above 60% average DoD.

ANY discharge of a battery consumes cycle life, but stopping at 50% has a tiny benefit compared to higher levels.

Confusion arises because system designers use a rule of thumb that based on load and charging availability, the most economical battery or battery bank choice is one that will average 50% DoD in use when new. In RV use, that means if you routinely find yourself discharging your battery bank below 50%, you should probably choose a bigger battery or bank next time.

Manufacturers don’t readily make these charts available, but the curve shape is very similar for all types of lead-acid batteries and lithium ion batteries. The cycle numbers vary.

[ncitro]

I have a new 2021 Transcend xploror and the refrigerator seems to stop working and then works. I’ve had repair people and even GD come and replace the whole fridge. Shortly after the fridge was replaced, the new fridge started doing the same thing, the gd guy told me to get the battery tested and the battery tested bad. The rv os connection to shore power. Fast forward 4 months and again fridge having issues, got the battery tested, came out bad, got it replaced. What could be doing this?

If it actually tested bad (either with your own tester or at an auto parts store or similar) I'd agree that you discharged them too far or left them discharged for too long, or you boiled them dry and ruined the plates. The battery should be under warranty in that short of a period, but I would suggest a battery monitor (I am partial to Victron) that will help you keep track of your state of charge better.

[Yoda]

one other thought - make sure your battery disconnect switch is ON (key cant be removed) If it is off the converter will not charge the battery.

[Guest]

The 50% SOC is a general rule to minimize cost and extend usage. A lead acid battery at 12.0V is discharged and will not maintain a load for very long beyond this point at 2v/cell. When each cell reaches 1.9v or 11.6 overall, the batteries is being damaged each time it is discharged to this level. If its left in this state it will sulfate and the battery will be ruined.

Most lead acid batteries that are installed in our rigs are not commercial grade or AGM or Gel. At 50% DOD usage we may see 5 years use or around 500 cycles at best.

Lithium is no different where dollars spent result in maximum usage by discharging to 20% or higher and to charge to 80%. Charging to 80% can be a major inconvenience but discharging to no lower than 20% is easy with a battery monitor.

Store lead acid batteries always at full charge and do not use a trickle charger that has the potential to bake the battery dry and ruin it.

Store Lithium batteries at 50% SOC since these battery types degrade the least when they sit for long periods of time at their midpoint.

These methods have served me well in RV, Auto, Marine and RC planes where lithium batteries are severely abused.

Jim