Batteries Die in a Few Hours! HELP!

[JRTJH]

I haven't seen a Keystone trailer (since about 2010) with anything smaller than a 55 amp WFCO converter/charger. With that size charger, assuming it is working properly, ALL of the output amperage that is not being used by the trailer systems is available to charge the battery bank (at the appropriate level).

That means, if you have a WFCO 55 amp power center, if your trailer is parked with the refrigerator and safety systems running (typical storage status) then you'll be using about 5 amps of DC power to operate the trailer systems and the remaining 50 amps is available to recharge the batteries.

Most "stand alone battery chargers" are 8/10/15 amps "maximum charge availability" and a few "high dollar chargers" can provide up to 25-35 amps to recharge batteries. Few "stand alone battery chargers" can come close to the recharge capacity of the typical RV converter/charger in "modern RV systems"....

That's not to say older trailers with a 25 or 35 amp converter won't "struggle for days" if you're using the furnace and burning lots of incandescent lamps, but anything built after about 2010 will have no problem maintaining a dual 12 volt or a dual 6 volt battery bank with the onboard WFCO system.

[sonofcy]

Originally Posted by flybouy

I don't understand the comments about the "standard converter" charge rates. The lowest Wfco set up is a 30 Amp 12v DC 3 stage charger. I don't think it would take "days" to recharge even 2 "fully discharged" batteries.

I have a Progressive Dynamics PD4500 75Amp converter in my Montana. I also have a Trimetric TM2030RV battery monitor. When I disconnect my shore power to test how long my batteries will last or something like a power failure happens, I can watch the current flow on my meter. The converter can supply as much as 14.4V in boost mode but only 13.6V in normal mode and 13.2V in storage mode. I do not know when boost mode starts, but it is not critical to know because it cuts out at 90% in any case as does normal. The last 10% is done at 13.2V which will take a while. The converters RV manufacturers put in are designed on the assumption that the rig is always on shore power and the converter is mainly a float charger. See the following for more details .
https://batteryuniversity.com/learn/...d_acid_battery
If you really want to dig into the details of FLA spend some time reading
http://www.jackdanmayer.com/Batteries_and_charging.html

[sonofcy]

Originally Posted by JRTJH

I haven't seen a Keystone trailer (since about 2010) with anything smaller than a 55 amp WFCO converter/charger. With that size charger, assuming it is working properly, ALL of the output amperage that is not being used by the trailer systems is available to charge the battery bank (at the appropriate level).

That means, if you have a WFCO 55 amp power center, if your trailer is parked with the refrigerator and safety systems running (typical storage status) then you'll be using about 5 amps of DC power to operate the trailer systems and the remaining 50 amps is available to recharge the batteries.

Most "stand alone battery chargers" are 8/10/15 amps "maximum charge availability" and a few "high dollar chargers" can provide up to 25-35 amps to recharge batteries. Few "stand alone battery chargers" can come close to the recharge capacity of the typical RV converter/charger in "modern RV systems"....

That's not to say older trailers with a 25 or 35 amp converter won't "struggle for days" if you're using the furnace and burning lots of incandescent lamps, but anything built after about 2010 will have no problem maintaining a dual 12 volt or a dual 6 volt battery bank with the onboard WFCO system.

I have watched the current on my Trimetric TM2030RV and the charger simply does not work the way you think. As the battery is charged it's internal resistance increases and the current drops. Here is a sample charge curve and article.
https://batteryuniversity.com/learn/...d_acid_battery
I lived thru a multi day power failure last winter and watched how the batteries reacted over a 3 day period. I was letting them drop to 70% before turning on a pair of Honda 2000 W gennies in parallel. If my memory serves, I lasted 6 hours on battery and spent 6 more hours to recharge but I was forcing the converter to put out 14.4V instead of 13.2V. It would have taken MUCH longer at 13.2, maybe not days buit certainly over 12 hours. These were almost new T105's. I apologize for the literary license that has offended some of my fellow forum members. IOW, many hours as in 12-18 NOT days.

[flybouy]

Originally Posted by nickofosho

Thanks for all the input!

...
I've monitored them with a volt meter many times and as soon as they are hooked up to the trailer, they begin loosing voltage, about 1/10 volt in 5-10 minutes. When they are disconnected, the voltage remains stable/consistent.
...

A drop in voltage is not a good measurement for the amps (load) on a battery. It is an indication if there is no load connected as to the state of charge of the battery. Taking a voltage reading not knowing the "true" charge of the battery is useless. What make/model meter are you using? Most "inexpensive" VOM are able to read a DC Amp draw up to 10 amps.
If you want to do a very crude test get an inline fuse holder and connect between battery positive post and batter positive cable. Get several fuses ov varying amperage. Start off with a 5 Amp. If it blows go up, if it doesn't go lower. With everything off the amperage should be well under 5.

[sonofcy]

Originally Posted by jimborokz

Is there some system that can be set up to shut off batteries when they reach 50%. I'm thinking in the middle of the night when you're not watching a monitor and the furnace is running. I'd rather have it get a bit cool than run that battery down to 20% or even 0.

Yes there is but if he won't even spend the $200 for a Trimetric kit to properly monitor the batteries there is no way he will spend the several thousand for a Victron or Magnum Inverter Charger to do what you suggest.

[JRTJH]

Originally Posted by sonofcy

Yes there is but if he won't even spend the $200 for a Trimetric kit to properly monitor the batteries there is no way he will spend the several thousand for a Victron or Magnum Inverter Charger to do what you suggest.

Which is why I suggested that rather than spending money on a system to protect against an inadequate battery supply, just install an adequate battery supply that doesn't need protection. The cost is about the same, the end result is increased function rather than increased monitoring/protection for the "too small battery"

[sonofcy]

Originally Posted by nickofosho

Thanks for all the input!

The batteries are wired in parallel. The issue only occurs when not connected to shore power or to a generator. They have both been load tested and work fine. I have tried fully charging each battery independently (with the trailer's converter and confirming with the trailer battery monitor and a volt meter) and only connecting one at a time to the trailer and always get the same result. A dead battery in a few hours.

I've monitored them with a volt meter many times and as soon as they are hooked up to the trailer, they begin loosing voltage, about 1/10 volt in 5-10 minutes. When they are disconnected, the voltage remains stable/consistent.

They have never gone completely dead or anything below 10.5v. The trailer is always stored plugged into shore power and is rarely in storage for more than a month.

The emergency break away cable is intact and functional.

Is it possible that some short in the wiring could be causing a extreme parasitic draw?

Thanks again everyone!

A couple of things.
If you do NOT hook up the battery, then any short or even excess draw is being powered by the converter. If a dead short the fuse would blow, a high draw would either generate enough heat to be seen smoking or smell. Extremely rare but not impossible to have what you think is happening.
The slow drop in voltage may simply bethe effect of resting voltage drop after a top charge. Leave the battery disconnected overnight and I mean remove both + and - cables. Then hook it back up and measure voltage at the battery terminals. Better would be to get a clamp on ammeter, borrow, rent, buy. For occasional use a $30 meter is ok. Best is to get a $200 kit that includes the shut and Trimetric TM-2030RV battery meter. You will find that almost all full time RVers who boondock any amount will have one of those or a competitor's version but Trimetric is the gold standard.
I would recommend you get the TM-2030RV before you buy new batteries ($89 each at Costco) they aren't what I would buy but many use them for years depending on how well you adhere to the 50% rule and don't boondock very much.

[sonofcy]

Originally Posted by JRTJH

Which is why I suggested that rather than spending money on a system to protect against an inadequate battery supply, just install an adequate battery supply that doesn't need protection. The cost is about the same, the end result is increased function rather than increased monitoring/protection for the "too small battery"

Well he still needs a battery monitor, and an adequate supply depends on what he is doing. For me it's 600AH usable which is 12 T105's at a cost of $150? each and weighing 804 lbs, or as I am doing 6 Lithium's weighing under 200 lbs. He can probably get by on 2 T105's unless he has a residential fridge then he will need 4 plus of course a few $00 for solar. Again, it all depends on your usage profile. The more often you are off grid makes the cost higher. For me that is an infinite amount of time off electricity (need black tank dump every 10 days) at a cost of roughly $10,000 self installed. Freedom costs $.

[travelin texans]

Originally Posted by crowbar

If one battery is still in excellent condition there's nothing wrong with buying just one battery to replace the bad one. I've done it a number of times with no problem. To say that you should "never" change out just one battery makes no sense. Yes, it's ideal to change out both, but not everyone has an extra $400 burning a hole in his pocket. If this guy did, he could pay for a technician to come out and diagnose and repair his problem and job done. Not everybody is loaded with cash.

First of all I've NEVER spent $400 on a single, nor a pair, of 12 volt RV batteries.
Second, yes you can only replace the bad one, but in a few months you'll be replacing what you thought was the good one after the new one cannabalizes it, so actually you're paying more to replace batteries one at a time than to do it properly the 1st time.
By all means if you want to replace them one at a time & pay $400 each, please do so, it's your $$$, but in my experience & recommended by battery pros you should replace both with matched pairs for longevity.

[JRTJH]

Originally Posted by sonofcy

Well he still needs a battery monitor, and an adequate supply depends on what he is doing. For me it's 600AH usable which is 12 T105's at a cost of $150? each and weighing 804 lbs, or as I am doing 6 Lithium's weighing under 200 lbs. He can probably get by on 2 T105's unless he has a residential fridge then he will need 4 plus of course a few $00 for solar. Again, it all depends on your usage profile. The more often you are off grid makes the cost higher. For me that is an infinite amount of time off electricity (need black tank dump every 10 days) at a cost of roughly $10,000 self installed. Freedom costs $.

I think you're trying to "sell a Rolls Royce" system to someone who's looking for a "Model T solution"... As for practicality, if a single GP 24 battery doesn't make it through the night AND YOU'RE LOOKING FOR A REASONABLY PRICED SOLUTION", then you don't want to monitor what doesn't work, you want to upgrade it (CHEAPLY) so that it will work… that would be, IMHO, installing adequate batteries and using the existing voltage monitor panel and converter/charger.

As exotic as your battery/charger system is, it would take a "weekend warrior" years/decades of use to even approach justifying that kind of expense.

Buying a "reasonably priced "auto-shutoff system" for a GP24 battery to prevent damaging it ???? Not practical if you're trying to make it through the night and the battery is disabled by 2AM.

Solution, rather than spend the $200 to install a "auto-shutoff", spend the $200 on a pair of GP27 batteries or a pair of GC2 batteries that will make it through the night, keep you comfortable (rather than shutting you down) and you'll still have power to spare to get the next morning started.....

Seems reasonable to me, without spending $5000+ on lithium batteries and outrageously priced charging/monitoring systems for a "entry level trailer with a power hungry furnace"....

For me, it's a matter of perspective not a matter of "how expensive and exotic can we get".

[flybouy]

John hit it out of the park. If someone asks how to change a tire on their Toyota Corolla bragging about you're $1,000 + racing tires and you're $200 tire pressure gauges isn't particularly helpful. JMHO

[sonofcy]

Originally Posted by travelin texans

First of all I've NEVER spent $400 on a single, nor a pair, of 12 volt RV batteries.
Second, yes you can only replace the bad one, but in a few months you'll be replacing what you thought was the good one after the new one cannabalizes it, so actually you're paying more to replace batteries one at a time than to do it properly the 1st time.
By all means if you want to replace them one at a time & pay $400 each, please do so, it's your $$$, but in my experience & recommended by battery pros you should replace both with matched pairs for longevity.

If boon docking a lot which means you are a full time RVer you are most likely using Trojan T105's which cost about $170 each or $340 for a pair which is a 12V battery bank with a usable 112.5 Ah or 1.35 kWh of power. Many modern (Residential fridge) RVers will use 4 of those so replacement cost is $680 every few years. At 50% depth of discharge the batteries are good for about 1,200 cycles. At one cycle a day, that is 3.29 years. A bigger bank will last longer as in doubling results in 1 cycle every 2 days etc.

[sonofcy]

Originally Posted by JRTJH

I think you're trying to "sell a Rolls Royce" system to someone who's looking for a "Model T solution"... As for practicality, if a single GP 24 battery doesn't make it through the night AND YOU'RE LOOKING FOR A REASONABLY PRICED SOLUTION", then you don't want to monitor what doesn't work, you want to upgrade it (CHEAPLY) so that it will work… that would be, IMHO, installing adequate batteries and using the existing voltage monitor panel and converter/charger.

As exotic as your battery/charger system is, it would take a "weekend warrior" years/decades of use to even approach justifying that kind of expense.

Buying a "reasonably priced "auto-shutoff system" for a GP24 battery to prevent damaging it ???? Not practical if you're trying to make it through the night and the battery is disabled by 2AM.

Solution, rather than spend the $200 to install a "auto-shutoff", spend the $200 on a pair of GP27 batteries or a pair of GC2 batteries that will make it through the night, keep you comfortable (rather than shutting you down) and you'll still have power to spare to get the next morning started.....

Seems reasonable to me, without spending $5000+ on lithium batteries and outrageously priced charging/monitoring systems for a "entry level trailer with a power hungry furnace"....

For me, it's a matter of perspective not a matter of "how expensive and exotic can we get".

How does he prevent damaging the new batteries he buys if he doesn't know how deeply he is discharging them?

[JRTJH]

Originally Posted by sonofcy

If boon docking a lot which means you are a full time RVer you are most likely using Trojan T105's which cost about $170 each or $340 for a pair which is a 12V battery bank with a usable 112.5 Ah or 1.35 kWh of power. Many modern (Residential fridge) RVers will use 4 of those so replacement cost is $680 every few years. At 50% depth of discharge the batteries are good for about 1,200 cycles. At one cycle a day, that is 3.29 years. A bigger bank will last longer as in doubling results in 1 cycle every 2 days etc.

First of all, the price you quoted for GC2 batteries is WAY off for US pricing. Duracell GC2 batteries are available at Sams for $89 and Interstate GC2 batteries are available at Costco for $97 each. That's $178 or $194 respectively. The Passport 240BH that the OP has doesn't have a Residential fridge nor does it need 4 batteries to power such a "non-existent beast".

We're (at least I am) talking about a realistic solution in a small RV trailer, not a system needed to power a 40' "residential fifth wheel".... The analogy that Marshall just posted about changing a tire on a Corolla and discussions about $1000 racing tires and $200 pressure gauges is "far removed from his Corolla just as your "multiple lithium batteries, residential refrigerators and solar systems are "in outer space" when considering his problem and solutions..... Now, had he asked, "How exotic can I go with an unlimited budget to achieve total electrical independence?" But that's not what he asked, is it ???

As for your question, "How does he prevent damaging them?" I've got a "two 6 volt battery system and a cigarette lighter plug in voltmeter. I've got 6 years on the current batteries and no reason to replace them this coming year. I "prevent damaging mine" by turning on the volt meter occasionally and reading the output voltage, as long as it's above 12.8 volts, I keep watching TV, when it gets down to 12.4 volts or so, I turn off the TV and make a mental note that I need to run the generator in the morning for a couple hours....

It simply isn't "exotic rocket science" to employ a battery powered RV. Now, if you like gadgets and have the bucks to spare, there's no harm in adding as many toys as your budget and GVW will allow. But are they "MANDATORY" to use an RV? Quick answer: Nope, not by a long shot. In fact, RV'ers have been getting along just fine for at least the last 50 years without lithium batteries, exotic monitors and expensive chargers and most importantly, without the monthly payments they bring to an enjoyable RV experience.

All the OP needs is a couple of adequate batteries to solve his problem, everything else is "overkill" for his needs.... Want's, Christmas lists, birthday gifts from a rich uncle??? now those are a different story.....

[flybouy]

From reading thru the posts here's my thoughts.
The OP states that he's tested the batteries and"thinks they are fine" but when asked how he tested gives no answer.
He also states that it's almost always "connected to shore power". No info if he's ever checked the battery level. When it's been suggested that he buys a $12 hydrometer, or takes the battery to a knowledgeable battery dealer to have it load tested, no response.
Seems to me most folks trying to help him are pointing to the batteries because logically if 2 good batteries have gone dead in a short time repeatedly, without blowing a fuse, then some evidence such as the smell of burning wire insulation, or the failure of an appliance would be present.
Seems to me is he's convinced his batteries are not the culprit and is unwilling to confirm it.

I wish him luck with finding the issue. JMHO

[sonofcy]

Originally Posted by flybouy

John hit it out of the park. If someone asks how to change a tire on their Toyota Corolla bragging about you're $1,000 + racing tires and you're $200 tire pressure gauges isn't particularly helpful. JMHO

I wasn't trying to brag, simply pointing out that folks have differing requirements that have different cost solutions. I understand that $10,000 seems like a lot, but consider that 250 camping nights at $40 each is $10,000. A payback time of 1 year. Yes that solution could be less with a longer payback, it's a criss cross graph. We chose to get a residential fridge because they are bigger, operate much better, and last for longer than I will need the RV. Ours uses 3 A at 120 V MAX, 1.5 kWh per day which is 111% of a pair of Trojan T105's. Since it is possible to have several sunless or nearly so days in a row, I have read where it is a good idea to have a 3 day supply, therefore if we assume an additional draw of .5 kWh for a total daily of 2 and 3 days would be 6 kWh we need 4 pairs of T105's. Fortunately the 3 days might be extreme, and MPPT charge controllers as well as solar cells have come a long way so 2 pairs (4 6V GC2 batteries) will provide a usable 225 AH or 2.7 kWh. This will optimistically run the RV with some solar for the needed 3 days. In fact I may spend a couple thousand less depending on my ongoing usage studies if I can reduce the lithium to 4 batteries. For weekend warriors, or full timers that always hook up, all you need is a $200 TM-2030RV.

[flybouy]

Originally Posted by sonofcy

I wasn't trying to brag, simply pointing out that folks have differing requirements that have different cost solutions. I understand that $10,000 seems like a lot, but consider that 250 camping nights at $40 each is $10,000. A payback time of 1 year. Yes that solution could be less with a longer payback, it's a criss cross graph. We chose to get a residential fridge because they are bigger, operate much better, and last for longer than I will need the RV. Ours uses 3 A at 120 V MAX, 1.5 kWh per day which is 111% of a pair of Trojan T105's. Since it is possible to have several sunless or nearly so days in a row, I have read where it is a good idea to have a 3 day supply, therefore if we assume an additional draw of .5 kWh for a total daily of 2 and 3 days would be 6 kWh we need 4 pairs of T105's. Fortunately the 3 days might be extreme, and MPPT charge controllers as well as solar cells have come a long way so 2 pairs (4 6V GC2 batteries) will provide a usable 225 AH or 2.7 kWh. This will optimistically run the RV with some solar for the needed 3 days. In fact I may spend a couple thousand less depending on my ongoing usage studies if I can reduce the lithium to 4 batteries. For weekend warriors, or full timers that always hook up, all you need is a $200 TM-2030RV.

From the OP's statement on no problems on shore power or generator, and having it stored plugged into shore power It didn't appear to me that he wasn't using it that often (not fulltiming), nor boondocking for long periods as he stated "it used to last 36 hrs.

[sonofcy]

Originally Posted by JRTJH

First of all, the price you quoted for GC2 batteries is WAY off for US pricing. Duracell GC2 batteries are available at Sams for $89 and Interstate GC2 batteries are available at Costco for $97 each. That's $178 or $194 respectively. The Passport 240BH that the OP has doesn't have a Residential fridge nor does it need 4 batteries to power such a "non-existent beast".

We're (at least I am) talking about a realistic solution in a small RV trailer, not a system needed to power a 40' "residential fifth wheel".... The analogy that Marshall just posted about changing a tire on a Corolla and discussions about $1000 racing tires and $200 pressure gauges is "far removed from his Corolla just as your "multiple lithium batteries, residential refrigerators and solar systems are "in outer space" when considering his problem and solutions..... Now, had he asked, "How exotic can I go with an unlimited budget to achieve total electrical independence?" But that's not what he asked, is it ???

As for your question, "How does he prevent damaging them?" I've got a "two 6 volt battery system and a cigarette lighter plug in voltmeter. I've got 6 years on the current batteries and no reason to replace them this coming year. I "prevent damaging mine" by turning on the volt meter occasionally and reading the output voltage, as long as it's above 12.8 volts, I keep watching TV, when it gets down to 12.4 volts or so, I turn off the TV and make a mental note that I need to run the generator in the morning for a couple hours....

It simply isn't "exotic rocket science" to employ a battery powered RV. Now, if you like gadgets and have the bucks to spare, there's no harm in adding as many toys as your budget and GVW will allow. But are they "MANDATORY" to use an RV? Quick answer: Nope, not by a long shot. In fact, RV'ers have been getting along just fine for at least the last 50 years without lithium batteries, exotic monitors and expensive chargers and most importantly, without the monthly payments they bring to an enjoyable RV experience.

All the OP needs is a couple of adequate batteries to solve his problem, everything else is "overkill" for his needs.... Want's, Christmas lists, birthday gifts from a rich uncle??? now those are a different story.....

The price I quoted was my Canadian price converted to USD and is a discounted price. I have no idea if the batteries you mention are equivalent to Trojan quality and lifetime. I have heard that Trojan makes the guts for an Interstate battery and Interstate then wrap a container around the guts. If that is the one it is indeed a good buy.
As to the rest of it, it does seem I did not read the OP closely enough and got off on a tangent. My apologies if I seemed anything but helpful, it was not my intent. I do appreciate being called to task when I make a mistake. Thank you.

[nickofosho]

Update!

So, one of the batteries was dead. I did another load test on each battery and one needed to be replaced. Not sure what happened with the first load test...
Also, I now realize I was draining my batteries to 0% on most dry camping trips. I didn’t understand how that worked so thank you to everyone for explaining this to me!

Swapped the dead battery and we set out on a week long dry camping trip and the batteries both worked great. And I made sure not to let the charge go below 50% using our trusty generator.

Thanks again for all the input everyone!!

[JRTJH]

Originally Posted by nickofosho

Update!

So, one of the batteries was dead. I did another load test on each battery and one needed to be replaced. Not sure what happened with the first load test...
Also, I now realize I was draining my batteries to 0% on most dry camping trips. I didn’t understand how that worked so thank you to everyone for explaining this to me!

Swapped the dead battery and we set out on a week long dry camping trip and the batteries both worked great. And I made sure not to let the charge go below 50% using our trusty generator.

Thanks again for all the input everyone!!

If you drained both batteries to "near 0 volts" and one shorted out/won't recharge, chances are very VERY good that the other battery also was "drained to 0 volts" and was never properly charged (or overcharged) by the faulty battery in the same charging circuit. So, if you only changed out the bad battery, I'd suspect that in about a month, you'll be facing the same issues again. The "older of the two batteries" is now the "weakest link" and will drag the new battery down to its capacity within a couple of charge cycles.

When changing batteries in a multiple battery system, all the manufacturers recommend ALWAYS changing all the batteries with ones that are the same size, same amperage and same age. Otherwise, they will all be "limited by the weakest link".