Do batteries just begin to age? 2018 View 24D

[SeeTheUSA]

I began to see some different behavior from my coach batteries, wondering if they are just getting tired or do I have a problem?

Background … 2018 View 24D, PD9245 converter, 400w of rooftop solar, two Trojan T-1275’s for 300ah of storage capacity, transfer switch, Bluetooth surge protector. Our rig is nearly always plugged into shore power, either when we’re in it at an RV park or when in storage. My Renogy battery monitor has nearly always shows 99-100 percent, has for the approximately five years with the above mentioned arrangement. Occasionally I’ve seen it as low as 85 to 90 percent after being parked on our driveway overnight or after an overnight stay at a WalMart, but things fairly quickly recharged to capacity once on the road or the solar panels get a few hours of sunshine. I have always kept a close eye on the batteries for any signs of corrosion and add distilled water before any plates become uncovered. I always have exercised my generator monthly, which of course in storage means unplugging and restoring the shore power.

About two weeks ago I checked things after servicing the generator, which included running it to check my work, then topped off the coach battery cells with distilled water. All seemed normal, but a day or two later noticed the Renogy indicated about a 75 percent amp hour charge (I probably didn’t check the amp hour reading after completing my tasks that day). Hmmm, seemed odd. Saw about 13.6 volts of converter output, but very low amps and watts input. In the last week I have checked many things, such as battery cable connections, converter operation (at the converter with a multimeter), Zamp controller settings, various fuses which are strewn about inconveniently and, as I went along, my own mental state … the result has changed very little. The Renogy now shows 79 percent, or 237 amp hours. Still charging, but 0.10 amps and 1 watt. I tried putting the converter in the maximum mode with the Wizard fob, saw 14.4 volts or so output as you’d expect.

All indications tell me the batteries are fully charged, but shy of the 300 amp hours they typically show. Any thoughts? Are my Trojans just aging (like me!) ? The batteries are about five years old.

 

[creativepart]

Well, it can be both normal and/or battery aging.

If the batteries are 7 years old, they can be losing their staying power. But on the other hand. If your batteries are nearly fully charged then the internal resistance will naturally reduce the amps being received from the charger. This is totally normal so it doesn't mean you have a problem.

To get a better assessment of their state of charge get yourself a hydrometer and check the electrolyte to see the charge of each cell and each battery. It's possible that one cell or one battery is showing it's age more than another. The hydrometer will give a more complete picture than a voltage meter for a battery that's not perfectly at rest.

It can be a lot of things, connections, your converter, one battery or both batteries or nothing at all. You probably need more real world experience and testing to know if it's something or nothing.

 

[klook]

After 5 years I would expect a little performance drop off. It might even be good to discharge them a bit as it seems you have not used them fully. Take them down to 50% and charge them back up. Or try one of the chargers that uses high frequency AC current to "fix" the batteries. NOCO chargers do this and I have "fixed" a couple of batteries. Not as good as new but functional.

 

[RVL895540]

Flooded lead acid batteries need periodic equalization. After the batteries are fully charged, equalization voltage, typically about 16 volts, is applied for a couple of hours.

From Google: Equalizing flooded batteries is a controlled overcharge to counteract sulfation and acid stratification, which improves their performance and extends their lifespan. This process is essential because normal charging alone often cannot reverse the hardening of sulfate crystals on the plates or the uneven distribution of electrolyte, which can reduce battery capacity over time. Equalization also helps to balance the charge across all cells in a battery pack, ensuring all cells have equal voltage.

 

[Morich]

Yes, lead acid batteries do age. But there are lots of different ways to extend the lifetime and it is often done on more expensive batteries like used in industrial setups.
There are several different things that can be done to extend the life. Things like taking them out of service for a bit and changing out the acid/water mix. Different charging and more work on keeping them clean are always an option.

But the small batteries we use in RV/automotive work are so cheap that it doesn't work out to go to the trouble and expense of saving them. The training and labor are just not practical in our RV use.

A couple points that may be adding to the mystery is that most monitors are more an estimated guess than actual readings that tell us much. One thing likely to skew the results a bit is the way power is being used while the monitor is estimating what is happening at the batteries. The monitor itself is using power as it is trying to come up with the estimates and there are always other items in use as well.
One of the big issues with getting a better voltage reading is to let the battery become stable before we do the test. So if there are things using the battery WHILE the test is done, there is no way the estimate is going to be very good on the real condition of the batteries!
Any voltage test we do is done at the posts and that can only tell us about that one cell, while the third one over may be totally different, if we have not let the battery settle and let the different cells level out somewhat.

But the simple answer is that the batteries do get old!

 

[klook]

That is why the hydrometer test of each cell is best.

 

[SeeTheUSA]

Thanks all for your replies. I should have mentioned up front that a hydrometer indicates healthy cells with virtually no deviation from cell to cell.

The best I can tell there is nothing wrong … although my battery monitor has increased only to 82% charge, short of the full 300 amp hours. I did have the motorhome out yesterday from under the covered storage. Nice sunny day and the solar panels were chunking out a significantly better charge than the converter.

I’ll try later to let them discharge to about 50%, then recharge from there. Maybe that will help.

 

[MadMaxWinny]

All good input. In theory, a battery kept at the Float voltage doesn't appreciably age. Of course, we use our batteries and every full discharge (50+%) or less takes its toll. At some point the previously mentioned Equilization charge can at least partially restore a battery which is showing its age. Things to keep in mind: the Float stage (90-100%) often takes 8+ hours to achieve, providing that the charge source is providing the proper voltage. Also, modern Amp-hr meters occasionally need to be synchronized (basically zeroed out).

 

[RayIN]

Check the Renogy website, I think they do not recommend equalizing their batteries; each battery company has different recommendations.

 

[ldfeat]

When its time to change your batteries, consider AGMs. No water servicing needed. I like Lifeline, Absorbent Glass Mat AGM Battery Manufacturer USA- Lifeline Batteries. Larry, 2014 Reyo P

 

[NASCARUSS1953]

I began to see some different behavior from my coach batteries, wondering if they are just getting tired or do I have a problem?

Background … 2018 View 24D, PD9245 converter, 400w of rooftop solar, two Trojan T-1275’s for 300ah of storage capacity, transfer switch, Bluetooth surge protector. Our rig is nearly always plugged into shore power, either when we’re in it at an RV park or when in storage. My Renogy battery monitor has nearly always shows 99-100 percent, has for the approximately five years with the above mentioned arrangement. Occasionally I’ve seen it as low as 85 to 90 percent after being parked on our driveway overnight or after an overnight stay at a WalMart, but things fairly quickly recharged to capacity once on the road or the solar panels get a few hours of sunshine. I have always kept a close eye on the batteries for any signs of corrosion and add distilled water before any plates become uncovered. I always have exercised my generator monthly, which of course in storage means unplugging and restoring the shore power.

About two weeks ago I checked things after servicing the generator, which included running it to check my work, then topped off the coach battery cells with distilled water. All seemed normal, but a day or two later noticed the Renogy indicated about a 75 percent amp hour charge (I probably didn’t check the amp hour reading after completing my tasks that day). Hmmm, seemed odd. Saw about 13.6 volts of converter output, but very low amps and watts input. In the last week I have checked many things, such as battery cable connections, converter operation (at the converter with a multimeter), Zamp controller settings, various fuses which are strewn about inconveniently and, as I went along, my own mental state … the result has changed very little. The Renogy now shows 79 percent, or 237 amp hours. Still charging, but 0.10 amps and 1 watt. I tried putting the converter in the maximum mode with the Wizard fob, saw 14.4 volts or so output as you’d expect.

All indications tell me the batteries are fully charged, but shy of the 300 amp hours they typically show. Any thoughts? Are my Trojans just aging (like me!) ? The batteries are about five years old.

The Progressive Dynamics PD9245 is a 4 stage charger/converter that cycles every 21 hours with high voltage to desulfate the batteries. I just changed my batteries after 9 years being plugged into shore power 24/7/365 except when dry camping at the races. I build golf carts and am very familiar with Trojan GC batteries. First off they are the best lead acid battery you can buy, but at 5 years they will start showing a little bit of decline, but they should still provide about 8 years of service. A check with a hydrometer is a good idea just in case there is a problem. If you do need to replace the batteries and you have the room it would be better to go with 4... 6V trojans wired in series/parallel, or if not enough room just use 2...6V, the 2 6V batteries will equalize much better than 2... 12.. Also your 2... 12V trojans should be connected to PD converter/charger by a POS on 1 battery and NEG on other.

 

[SeeTheUSA]

To follow up … all I needed to do was reset my Renogy battery monitor. Not sure why it would suddenly send out an erroneous SOC reading, but it’s good to be back to normal