Boondocking - do my batteries need to be replaced?

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JoelP

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Nov 2, 2016
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San Jose, CA
I invited my daughter and her family from to spend the night in my RV while the smoke is so heavy from the fires just north of them. I parked where I couldn't easily plug in but only ran 2 fans for 3 hours and then one LED light and one Fantastic fan.  To my knowledge nothing else was drawing current. The 2  coach batteries died by the time that 15 hours had elapsed.  All would have been OK except that the depleted battery set off the CO detector at 3:00AM.  I had to start the engine to be able to start the generator, which stopped the CO detector from sounding of.

I have a solar panel on the roof that keeps this battery charge maintained during storage.  Occasionally I check the fluid in the cells and they never seems to need any water.  As for the age of these batteries, I am unsure since they came with the vehicle from the prior owner.

Normally I only used this when plugged in at a campground, so I have little experience with what to expect.  What is reasonable to expect when boondocking like this for that small amount of electrical load?
 
Take the batteries out and run them down to an auto supply store or Walmart and have them checked, they are probably bad, but the only way you will know for sure is to test them.
 
I would fully charge the batteries and then check them with an hydrometer.
 
JoelP said:
I invited my daughter and her family from to spend the night in my RV while the smoke is so heavy from the fires just north of them. I parked where I couldn't easily plug in but only ran 2 fans for 3 hours and then one LED light and one Fantastic fan.  To my knowledge nothing else was drawing current. The 2  coach batteries died by the time that 15 hours had elapsed.  All would have been OK except that the depleted battery set off the CO detector at 3:00AM.  I had to start the engine to be able to start the generator, which stopped the CO detector from sounding of.

I have a solar panel on the roof that keeps this battery charge maintained during storage.  Occasionally I check the fluid in the cells and they never seems to need any water.  As for the age of these batteries, I am unsure since they came with the vehicle from the prior owner.

Normally I only used this when plugged in at a campground, so I have little experience with what to expect.  What is reasonable to expect when boondocking like this for that small amount of electrical load?

How long have you owned the coach. I see where it's a 2010 so it's possible the batteries are the originals. If they are, you did good for them lasting 7 years IMHO.
 
Odds are the battery(s) are just plain worn out. The typical marine/RV so-called deep cycle has a service life of about 3 years, and the capacity deteriorates badly toward the end of that.  If they are a better quality deep cycle, e.g gold cart 6v's, you could expect 5-10 years with decent care, but even so the battery in a 2010 coach would probably be near end of life.

Since you rarely camp off-grid, I'd probably get another marine/rv type for a modest price. However, you might want to review my article on RV Battery Choices in the RVforum Library at http://www.rvforum.net/miscfiles/Choosing_right_battery.pdf
 
That actually does not sound too bad to me... I would recommend re-charging daily using a portable generator or other generator.. Depending on your Converter 1000 to 2000 watt will do. A Genrac 1000 will run for about 8 hours on one tank of gas and powwer a Progressive 9180.

A Honda EU-1000i uses less gas but WILL NOT power the 9180  I think i twill a 9160 or 9260 but not sure.  The EU-2000i Will power any of 'em.  And burns about the same amount of gas as the Genrac

(The Genrac is a traditional generator, though fully enclosed so all the specs come close to the Honda EU2000i except not as many watts of power,, but weight, fuel consumption and noise, all about the same).. If you find a Genrac 1000 with WA8YXM on it.. let me know.. it's mine.)
 
Gary RV_Wizard said:
Odds are the battery(s) are just plain worn out. The typical marine/RV so-called deep cycle has a service life of about 3 years, and the capacity deteriorates badly toward the end of that.  If they are a better quality deep cycle, e.g gold cart 6v's, you could expect 5-10 years with decent care, but even so the battery in a 2010 coach would probably be near end of life.

Since you rarely camp off-grid, I'd probably get another marine/rv type for a modest price. However, you might want to review my article on RV Battery Choices in the RVforum Library at http://www.rvforum.net/miscfiles/Choosing_right_battery.pdf

I appreciate the feedback from everyone and especially Gary's article.  After running my Onan 5500 for an hour we turned everything off that I could it still ran the batteries down to the point the CO detector alarmed in 6 hours.  Today i will take one of these to Costco and buy their equivalent to a Trojan deep cycle that will fit the same space. I can see from the article that I should have been able to run for days rather than hours.
 
If your batteries were that low to start with, I don't think an hour of charging would bring them up to full charge.
 
JoelP,
You need to run your Generator for at least four hours and even then you won't get the batteries to 100%.
 
Fair enough, it needed to be charged longer, but even with half a charge it should have not died in 6 hours with nothing to speak of turned on. I am convinced these batteries are toast. 

BTW is it normal for a CO detector to sound an alarm when the battery is depleted? 

I did a quick look at Costco online and saw that they sell Interstate, the brand I currently have.  It seems that these are a notch below Trojans.  I will take a ride there to see what else they sell.  I don't want the replacement to fail in 4 years.  Before I head to Costco, I will measure the space that I have to see how much bigger I can tolerate for 2 batteries.
 
Most safety devices have an alarm that sounds when they can no longer function reliably, e.g. low power (battery or whatever), old or dirty sensor, etc. You need to know if the safety device is no longer protecting you.
 
before buying new batteries, remove what you have now, take them to a shop for a full charge and load test. That will let you know exactly what you have. Then you can make a decision to replace or not.
 
JoelP said:
Fair enough, it needed to be charged longer, but even with half a charge it should have not died in 6 hours with nothing to speak of turned on. I am convinced these batteries are toast. 

BTW is it normal for a CO detector to sound an alarm when the battery is depleted? 

I did a quick look at Costco online and saw that they sell Interstate, the brand I currently have.  It seems that these are a notch below Trojans.  I will take a ride there to see what else they sell.  I don't want the replacement to fail in 4 years.  Before I head to Costco, I will measure the space that I have to see how much bigger I can tolerate for 2 batteries.

If you are not sure of the state of charge or the specific gravity and the batteries are depleted to the point of alarms going off, 4 years of life may actually be pretty good. Do you know the battery model number and what charging voltage interstate recommends?
 
JoelP said:
BTW is it normal for a CO detector to sound an alarm when the battery is depleted? 

Are you sure you're not talking about the LP alarm which is located near the floor next to the propane stove. That detector typically is hard wired and will chirp when the battery is low. My CO (Carbon Monoxide) and smoke detector are battery operated and when their battery gets low, they will also chirp. 
 
Rene T said:
Are you sure you're not talking about the LP alarm which is located near the floor next to the propane stove. That detector typically is hard wired and will chirp when the battery is low. My CO (Carbon Monoxide) and smoke detector are battery operated and when their battery gets low, they will also chirp.

Rene - you are absolutely correct.  Once i got down on the floor and looked very closely I realized that this is the propane alarm.  That makes me wonder where I might have a CO detector.

kdbgoat said:
before buying new batteries, remove what you have now, take them to a shop for a full charge and load test. That will let you know exactly what you have. Then you can make a decision to replace or not.

I didn't get around to battery shopping yet, but noticed that the pan that holds these batteries restricts the footprint more than I had realized.  They are Interstate batteries with an MCA of 750, but I don't see a model number or size number and the date of purchase was not marked.  I plan to have them tested before i replace them just for my curiosity. 

Today the batteries were dead again and the alarm was sounding, but I plugged them into 120V for a few hours to bring them up in charge.  Strangely my level test indicator always shows these batteries as fully charged regardless of their situation of partial charge, a long as there is enough charge to light up the indicator. It makes me wonder just how that indicator functions and how to restore operation.
 
The rv wall monitor lights are pretty much useless. You want a digital volt meter and maintain a voltage of minimum 12 volts to about 12.7 when fully charged. If your batteries have been repeatedly discharged several times and not brought all the way back up they will seem to be charged yet fall on their face quickly. You are wasting your time by taking them somewhere to load test them. All they can do is put a toaster type load tester on them and they MUST be fully charged to do that.  Depending on your converters capability you may need to leave your batteries on charge for DAYS to fully drive the specific gravity back up. Go buy a battery hydrometer and check each cell. Be careful and wear eye protection as it is SULFURIC acid. It will blind you and eat holes in you and your clothes.

if the specific gravity is not driven back up you are wasting your time. If after a long charge the gravity wont come up or only some cells come up the battery is toast. If you have let the electrolyte drop below the top of the plates too often and exposed the plates the battery could very well be shot. If your converter is only capable of putting out 13.6 volts and depending how far the battery is from the converter, what size cable is between them and if there are any poor connections you could have low charging voltage at the battery. The chain is only as strong as the weakest link.
 
JoelP said:
Rene - you are absolutely correct.  Once i got down on the floor and looked very closely I realized that this is the propane alarm.  That makes me wonder where I might have a CO detector.

You may not have a CO alarm. They may not be required by code.
 
You may not have a CO alarm. They may not be required by code.

A 2010 Itasca definitely has a CO detector - RVIA standards required them even if state codes did not. It will typically be in the bedroom, mounted mid-high on a wall.

They are Interstate batteries with an MCA of 750, but I don't see a model number or size number and the date of purchase was not marked.

The MCA of 750 implies you have the SRM-27 Interstate, which is a Group 27 size and a "marine/RV" type hybrid battery. It had an RC rating of 160 minutes when new, and that is equivalent to about 105-110 amp-hours.  It's typical useful working life is about 3-4 years. Guessing that yours are original from 2010, I'd say they have lasted much better than average!  You can replace it with any Group 27 size battery, but one intended for deep-cycle use is best. The marine/RV type deep cycles are less expensive than the true deep cycles, but they don't last as long, so the cost per year of use is often similar for both types.
 
....but I plugged them into 120V for a few hours to bring them up in charge.  Strangely my level test indicator always shows these batteries as fully charged regardless of their situation of partial charge, a long as there is enough charge to light up the indicator. It makes me wonder just how that indicator functions and how to restore operation.

It takes many hours (ie up to 24 or more hours) to charge a discharged battery or batteries fully, several hours barely start it. For the Marine/RV type of battery, discharging them much more than 50% will quickly ruin them and result in a much shorter life.

The charge condition display, often found on a tank display unit, will always show full charge (5 lights) when plugged in or when the engine or generator is running on a motorized camper as they are reading the charger (alternator/converter) output (usually about 13.5 volts or better).
 
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