Battery Service Life

clubhouse · 01-10-2017, 04:41 PM

Curious how long one should expect for the service life of a well maintained batteries?

I have (2) Group 24 Costco Kirkland Batteries, purchased together and both mfg in Jan 2014, that just turned 3 years old. We primarily camp w/o electrical hookup, but have a generator that is used to recharge daily.

We have taken many of the power saving measures like converting to LED so I don't think I really put extreme loads on them even. Furnace would the highest load and that is only in the evening on cold trips. We camp on average 20 nights a year, about 1/2 are during the winter.

When not camping the batteries are religiously kept in my garage on a Battery Tender and topped off with distilled water.

To the best of my knowledge, the batteries have only been fully discharged once while in the shop for some service work. This would have been in the Fall of 2015 when the batteries were ~20 months old.

I realize group 24 batteries are not true deep cycle batteries. However I would have expected based on my usage and maintenance they would last a long time, 5+ years.

During our last trip over New years, I found that when I woke in the morning the batteries seemed to be discharged much more than typical while winter camping and running the furnace. I didn't get a accurate measument, but the LED control panel showed them down to 1/3; typically they would be 2/3 or Full based on that monitor.

We certainly didn't have any issues, but I am starting to wonder if this is a sign that maybe I shouldn't expect as long of a service life as I assumed.

Grumpy · 01-10-2017, 04:51 PM

Most say 5 years, however the batteries in my 08 SENECA were still good after 6 years. I think there are too many variables for a "specific" answer..

oldmanAZ · 01-10-2017, 05:14 PM

I'd suggest you start by buying a voltmeter to measure your battery voltage. Personally, I have no confidence in those LED lights in giving accurate information on the state of charge of my batteries.

When not camping it seems they are getting very good care. But when you are camping, you may be discharging them further than you realize and then may not be fully charging them with your generator. The heavy discharge and incomplete charging will shorten battery life.

As a guess, your batteries might last another season. But before you replace them, it would be a good idea to have the tools in place to KNOW to what extent you are discharging your batteries and KNOW that they are being fully recharged. Otherwise you may be disappointed again in the life of your new batteries.

**Mustang65** · 01-10-2017, 06:55 PM

This is one of those questions where if you ask 10 people, you will probably get 10 different answers. And they are probably all correct, based on how they used and maintained (or did not maintain) their batteries. Deep Cycle batteries need to be constantly monitored (especially if dry-camping). That 12.0VDC level for cut off ensures that you should have a 1200-1500 cycle life time.

I believe that the majority of RVers do not monitor their batteries while dry-camping, or in storage, wait let me rephrase that... they do monitor them... when the heater fan is barely turning or the slide outs only come in 1/2 way or the tongue jack only clicks, they know the batteries need a charge.

My battery life story. Purchased the TT had an Interstate 24-84Ah battery. Instantly added a second one. They were NEVER drained below 12.0VDC, water levels were always 1/4" below the ring. Here it is a little over 4 years they still hold a charge.

So, I contacted Trojan as I wanted to find out what the official test was for checking batteries that have been used for a few years and see what the CURRENT Ah value is. The following is from a post in the RVing with SOLAR social group.

My first test was performed on an old interstate battery to see what the CURRENT Ah would be. The battery is an Interstate 84Ah battery. It still takes a full charge and sits for months at 12.8VDC, without any charger on it. So to the average camper it looks like a good battery. Why did I do this test? So, I can eventually test my Trojan T-145 batteries, but decided to do a test on my original Interstate that came with the TT.

Battery information: Interstate SRM-24 84Ah (4 years old)
(Mostly used with my office UPS system and electronics projects)

Test Equipment:
Wind Turbine dump load resistor (15Amp load)

Test Information:
After an 8 Hour rest, Battery Voltage 12.98,

Test Results:
Voltage start 12.98VDC, Voltage End 10.5VDC
Test Time:
165 minutes

Calculations:
165 minutes / 60 minutes = 2.75 hours
2.75 hours * 15 amps = 41.25Amp Hours (current Ah available at full charge)
Useable Ah = 20.5Ah (not very much when you turn on a heating system or Tv…)

My Registry

Don

clubhouse · 01-10-2017, 07:51 PM

Quote:

Originally Posted by oldmanAZ

I'd suggest you start by buying a voltmeter to measure your battery voltage. Personally, I have no confidence in those LED lights in giving accurate information on the state of charge of my batteries.

When not camping it seems they are getting very good care. But when you are camping, you may be discharging them further than you realize and then may not be fully charging them with your generator. The heavy discharge and incomplete charging will shorten battery life.

As a guess, your batteries might last another season. But before you replace them, it would be a good idea to have the tools in place to KNOW to what extent you are discharging your batteries and KNOW that they are being fully recharged. Otherwise you may be disappointed again in the life of your new batteries.

Thank you.

I do have a multi-meter, but ironically it's in the TT and batteries are in the garage. Probably should buy a second to keep at home.

I agree those command center hushed are suspect at best.

clubhouse · 01-10-2017, 07:53 PM

Quote:

Originally Posted by Mustang65

This is one of those questions where if you ask 10 people, you will probably get 10 different answers. And they are probably all correct, based on how they used and maintained (or did not maintain) their batteries. Deep Cycle batteries need to be constantly monitored (especially if dry-camping). That 12.0VDC level for cut off ensures that you should have a 1200-1500 cycle life time.

I believe that the majority of RVers do not monitor their batteries while dry-camping, or in storage, wait let me rephrase that... they do monitor them... when the heater fan is barely turning or the slide outs only come in 1/2 way or the tongue jack only clicks, they know the batteries need a charge.

My battery life story. Purchased the TT had an Interstate 24-84Ah battery. Instantly added a second one. They were NEVER drained below 12.0VDC, water levels were always 1/4" below the ring. Here it is a little over 4 years they still hold a charge.

So, I contacted Trojan as I wanted to find out what the official test was for checking batteries that have been used for a few years and see what the CURRENT Ah value is. The following is from a post in the RVing with SOLAR social group.

My first test was performed on an old interstate battery to see what the CURRENT Ah would be. The battery is an Interstate 84Ah battery. It still takes a full charge and sits for months at 12.8VDC, without any charger on it. So to the average camper it looks like a good battery. Why did I do this test? So, I can eventually test my Trojan T-145 batteries, but decided to do a test on my original Interstate that came with the TT.

Battery information: Interstate SRM-24 84Ah (4 years old)
(Mostly used with my office UPS system and electronics projects)

Test Equipment:
Wind Turbine dump load resistor (15Amp load)

Test Information:
After an 8 Hour rest, Battery Voltage 12.98,

Test Results:
Voltage start 12.98VDC, Voltage End 10.5VDC
Test Time:
165 minutes

Calculations:
165 minutes / 60 minutes = 2.75 hours
2.75 hours * 15 amps = 41.25Amp Hours (current Ah available at full charge)
Useable Ah = 20.5Ah (not very much when you turn on a heating system or Tv…)

My Registry

Don

Thank you as well.

Looks like it might be a fun project to test my batteries with Trojan's test method. Would be interesting as a point of reference at the least.

**Mustang65** · 01-10-2017, 08:16 PM

I would recommend getting an inexpensive Digital Voltage Display to monitor your battery(s). There are a lot of them on Amazon. You can get one that plugs into your 12VDC accessory outlet or one that you can wire in. Either one is a lot better than none.

Don

mike837go · 01-16-2017, 02:36 PM

It's all based on how you use them.

I generally get 5+ years from the batteries in my cars and tractors.

No more than 3 from the TT because I deliberately use quite a bit of power from them while boondocking.

TaftCoach · 01-19-2017, 06:19 AM

I expect three years then start thinking about replacing. The heat of Texas, sometimes deep draws all lead to shorter life.

My primary goal is not to see how long I can get a battery to last. My goal is to enjoy my nights camping. We average 50 to 60 nights camping per year. If the battery lasts two years it cost me about a $1 a night. My beverage cost is higher and I'm not turning down that second drink to try and extend the life of that bottle.

Weird analogy but it's the best I got this early. Lol

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