Life of 6 volt batteries

[roddiemacdonald]

Have a 2018 CC Hathaway with four 6 volt batteries. The trailer has a residential fridge with inverter. I took the trailer into the dealer for warranty work, hauled it Sunday, dropped it off Monday morning picked it up Tuesday morning. It wasn't plugged in, I'm assuming lights were on during the day Monday while working on it, slides in and out, fridge left on, etc. I was able to hook up and leave Tuesday morning, retracting the slides and jacks. When I returned to the campsite, there was no battery life left, I had to hook up to shore power to get it off the truck.

Here's my question, am I expecting too much for the 4 batteries (less then a year old) to last more then 36 +/- hours with everything I had going on? Water levels in batteries are good.

Reason for asking, I'm still under warranty, and if I'm not out to lunch, I'll go after them for new batteries.

[formerFR]

first of all, just because you've had one instance of 'low batteries' doesn't make the batteries 'bad'... batteries are only a storage source for power, and if they are used and not recharged, then, yes, they are going to get low, no matter how 'many' you have, or if they are 6v or 12v or 24v, etc...

your situation is not one where you can readily access the battery life since you don't know what went on when you were not there. Dealers are great about leaving RVs unhooked from shore power, it's just not their priority. You also don't know if they left the inverter on, the fridge on, or if all of it was off the whole time. There are too many variables to throw out assumptions that your batteries are suddenly 'bad'.

Recharge you battery bank and you'll probably find that they word amazingly well for many off-grid activities and times, as long as you monitor their levels, keeping them above the 11.9 to 12.0 volts range, and charging them well when you are plugged in. Keeping the water levels right is certainly a priority as well.

As for the 'how long should the batteries be able to ___________' question, there are always too many variables for any of us to be able to tell you with absolute certainly: weather(temperatures), usage, charging amps, condition of the batteries, etc, all have to do with how 'long' they can do their job. How much 'stuff' you have in the fridge will impact how often it's compressor needs to run as well.

You may feel like this doesn't tell you much of what you want to know, but the reality is that you really have to get used to what 'your' coach and it's batteries will normally do for you - run some tests: park the RV in the driveway, unplugged, keep the fridge on an average setting, with the normal stuff inside, and see how long your fully charged 12.9 battery bank will hold until it eventually falls into the 12.0 to 11.9 range. You'll then have a good idea of the length of time between 'charging' the batteries.
This, of course, is about the fridge, if that's all you have in use during that time, but real life says that you'll also be using other 'things' while camping, off-grid, or traveling, while unplugged, such as lights and fans, water pump, etc., which will also be using the battery bank.

Once you travel and use the coach, you'll start to see more of a pattern as to the timing of your battery bank's usage... if the levels drop over 12 hours before needing a charge, for example, then you have a good measurement of how to manage your usage and recharging as you travel and camp, off-grid.

[njfishing]

Going on my 5th season with a pair of 6 volt golf cart batteries and they haven't missed a beat. They stay on the trailer through the winter without being trickle charged with kill switch off and I've never had an issue...

I don't however have an inverter or a residential fridge so my requirements aren't as demanding as yours...

Trick with these or any other batteries to prolong their life is don't run them down too low, although 6 volts are bit more tolerant to this then the average 12 volt..

If don't already have one, a volt meter comes in handy to assess the state of charge in volts... It doesn't have to be anything fancy, some people use these types which simply plug into the cigarette lighter adapter... https://www.amazon.com/INNOVA-3721-B...%2C143&sr=8-11


Here's a chart for you and in general you don't want to run your batteries down any lower then 12.4 volts or you run the risks of sulfation which will eventually reduce the life of your batteries.

Hope this helps you...

[KyDan]

You can get a panel mounted digital volt meter on Ebay in the $5 range.
Like this --> https://www.ebay.com/itm/LED-12V-24V...cFfhiDO1P9h_9A


I installed one in my wall panel where my slide, water pump, awning, water heater switches are. I added a push on push off switch just because it shines too bright at night when we're trying to sleep.
I reads in 10ths of a volt which you want. You should try to keep batteries from dis-charging below 12v for long life.
Happy Trails!

[Jim34RL]

If you think the batteries have failed. I would take them to a dealer who can load test the batteries for you. This is the only way to insure if a battery is good or bad. You can make the decision if they need to be warranty or not depending on the load test condition.

[Comanchecreek]

First set of 6 volts that I had lasted 8 years, and were still going strong when I traded in the trailer. The set I have now are 4 years old and so far so good. I'm sure your residential style fridge really pulls them down in a hurry. If it was on and so was everything else, like you say, you could expect them to go down. As others have said, load test them. That will give you an idea of how they are doing.

[clintbonnie73]

Go to Napa Store or go online and buy a Battery Tester Hydrometer.. It is the only good way to check the condition of your battery..(must have removable vent caps).. Easy to check.. be make sure the batteries are fully charged before checking.. If one cell is bad, replace the battery.. See:
https://www.napaonline.com/en/p/BK_7...ery+hydrometer

[babock]

The number of years is not a good indication of how long batteries last. The number of discharges is. For example, if you used your camper 3 weeks a year or 21 days and discharged them 50% every day, your batteries could easily last over 10 years. However, if you camped 100 nights a year, they may only last 3 years.

Another thing...people claim their batteries are still going strong after 6 years but if you actually measured the capacity of these batteries, they may only half their capacity left.

Bottom line...take what people say with a Costco sized grain of salt.

[TitanMike]

Originally Posted by Jim34RL

If you think the batteries have failed. I would take them to a dealer who can load test the batteries for you. This is the only way to insure if a battery is good or bad. You can make the decision if they need to be warranty or not depending on the load test condition.

Load testing really doesn't work all that well for testing deep cycle batteries. That is unless the load test is designed to fully discharge the battery to see how well it compares to it's designed amp hour capacity. Load testing where heavy loads are applied to see if the voltage will remain above 10-11 volts is done on starting batteries. Auto Parts Stores are the worst place to get a deep cycle battery tested. Most just use a small computer based tester that uses two set loads that merely calculates the internal impedance of the battery and compares it against a "table" in it's memory that was selected by the operators initial input (Cold Cranking Amp).

The best test for a Deep Cycle battery is to first charge it fully, let it sit for a few hours for battery temp to return to ambient and voltage to stabilize, then test with both volt meter and hydrometer. If cell connectors are exposed test each cell for wide differences in voltage and the hydrometer should show 1.265 at 80 degrees. Best to use a hydrometer with thermometer built in along with temp correction scale. If Specific Gravity varies more than 50 points between high and low cell battery is ready to be replaced.

Lastly, remember that even if one has four 6 Volt batteries in series/parallel that may add up mathematically to somewhere around 450 amp hours but in reality, since they are lead/acid batteries, only 225 amp hours should be used or battery life will fall off drastically.

As for what happens at the Dealership while being "repaired", not unusual for the stereo to be used for the tech's personal entertainment as well as all lights being turned on all day.

[BigRockr]

The 4 batteries are probably fine. I have a Silverback with 4-6V batteries. You are expecting WAAAY too much outa them. Get a Victron 712 so you can see your "state of charge". We run generator for 90 mins morning and evening to keep SOC from getting to low. After 12 hrs we are in the 70% discharged range. If you get down much lower you are beating on them pretty bad and decreasing their lifetime. Hope to go lithium at their next price drop. They can be taken down to 10% without concern, so we can run once a day. After having rv and res fridge, I'd never go back to rv fridge. Cools quickly and freezer is a freezer. My opinion only!!

[tomkatb]

This is what you can expect.

Residential 21 cubic foot residential refrigerators are not made for trailers.

Converting to 110 ac, inverters are 80-90% efficient. I sort of doubt a factory inverter is 90% efficient.

Get the watts used by the fridge. P=IV. In general a residential fridge plus a few lights will wipe out a battery in the summer in less than 12 hours.

Empty fridges use the most power.

I would check the water levels and plug into shore power. Likely you will need more than 24 hours for a complete recharge.

Likely minimum battery damage here. 6 volt batteries are pretty tough.

I bought the BM2 bluetooth voltmeter on Amazon for $40. Allows me to check voltage easy. Also it graphs usage. Nice to see.

The dealer should have explanned this to you. There is a lot of good about residential fridges. Unfortunately there has been minimal improvements in batteries. They just do not hold a lot of juice. There is no good way to store. electricity.

It’s the math. Having an on board generator completes the system.