Dead house batteries

Thank you for all the tips and good information.

I seem to get about five years from deep cycle batteries I buy at Sams Club.   I check my fluid levels monthly, winter and summer, whether in storage or during the travel season.  I also use one of these simple little cut off switches and I have used this same model on the last three or four rvs I owned and never had a problem with them. 

We often boondock for a couple of weeks at a time in the summer and with my solar (two hundred watts on the roof and one hundred portable) I can keep the batteries well charged and maintained. 

https://www.walmart.com/ip/LotFancy-Side-Post-Car-Battery-Disconnect-Switch-for-Car-Auto/385343216

Disconnect switch, watching the voltage levels and keeping the fluid level where it should be serves me well.   I am sure that AGM batteries would be a bit better, but I am long in the tooth and cheap 

Paul

Hi Paul,

For our chassis battery, I was about to purchase a battery disconnect switch that resembles the one you posted.  But then I was reading how they can come loose at the worst opportune time, so I decided to leave well enough alone.  I suppose if I were disconnecting frequently during trips like you, I'd consider one again.  If that knob was a handle instead, it would offer more leverage to tighten-down better.....less likely to come loose.

After reading this post I started looking at the cost of switching to AGM this is what  from Bateries & Bulbs store near me.

Frank, there are slim pickings out there right now for sealed lead acid, BCI Group GC2, 6V, deep cycle. Depending on your time expectations, I see three possibilities:

 

East Penn, 8AGC2, 190AH, $305 each, available within a week

Trojan, 6V-AGM, 200AH, $475 each, available mid-April

Lifeline, GPL-4CT, 220AH, $395 each, plus shipping from CA, available end of June

 

After reading this post I started looking at the cost of switching to AGM this is what  from Bateries & Bulbs store near me.

Frank, there are slim pickings out there right now for sealed lead acid, BCI Group GC2, 6V, deep cycle. Depending on your time expectations, I see three possibilities:

 

East Penn, 8AGC2, 190AH, $305 each, available within a week

Trojan, 6V-AGM, 200AH, $475 each, available mid-April

Lifeline, GPL-4CT, 220AH, $395 each, plus shipping from CA, available end of June

At these prices you may want to consider Lithium.  Lithium has almost twice as much useable energy storage capacity as Lead batteries.  It is recommended that for a reasonable life lead not be discharged below 50% state of charge and recharged to 100% promptly whereas some Lithium say you can go down to 15% SOC and does not have the same recharging requirement.  Other Lithium manufacturers say all the rated capacity is useable.  Thus two 200 ah 6 volt lead batteries have about the same useable storage as one 12 volt 100 ah Lithium.


There is a significant weight savings as well.  Two 6 volt lead batteries weigh 120-150 lbs where one Lithium weighs 25-35 lbs.


Lithium typically recharge at least twice as fast.  Also the self discharge rate of Lithium is significantly less when in storage.


The expected life as measured by the number of useable discharge/recharge cycles typically claimed by Lithium manaufactures  to be two or more times what can be expected from Lead batteries. I have seen Lithium warranties as long as 10 years.


For some PC cruisers a converter change may be required to supply the proper charge voltage to Lithiums.  Some of the earlier supplied converters were inadequate for Lithium and Lead as well relulting in shortened battery life.  I see prices for a new converter suitable for Lithium priced in $200-$250 price range.  Many of them claim ease of install.  I have no personal experience with changeout as I had a Progessive Dynamics converter installed by Phoenix when I bought my PC new which worked well for Lead and is approved by a Lithium battery manufacturer for use.


I have no financial interest in Lithium batteries or converters but I offer the above which might be helpful for anyone evaluating their options when needing to replace their coach batteries. Many RV manufacturers are now offering Lithium as an option with some making them standard thus I believe they are no longer thought of as experimental as they were just a few years ago.  Lithium prices also has been trending down.

Ron wrote:

 I suppose if I were disconnecting frequently during trips like you, I'd consider one again.  If that knob was a handle instead, it would offer more leverage to tighten-down better.....less likely to come loose.

I poorly worded my post's last line.   To clarify, I never disconnect our batteries when on a trip.   I was referring to the "off months" when the RV is in storage......like now.    I am happy to report that in using this type of disconnect for over 25 years I have never had one come loose.   I just tighten it up by hand really firmly.   Others may well have had dissimilar experiences with this type of switch.   

This is a really useful thread. I am also having problems with my batteries. I have a new PC as of last October. So I would like to know more what is considered the best practices to maintain batteries when not connected to shore power and in covered storage (so solar does not help). I have been turning off house power, and running generator about 20-30 minutes once a month, which seemed to work for my previous RV.  At first this seemed to keep batteries ok, generally 3-4 red lights on the battery display. But then after a few months it would get down to 2 lights within a month and the converter starting giving me the warning of low voltage. When I measured with a volt meter it was just below 12v so I worried that batteries were getting damaged. So I am thinking either batteries are defective or I am not doing my recharging enough, or there is something causing batteries to drain even though I have house battery power turned off  I do have 2 6v AGM batteries, which is what most people seem to recommend. So I really don't want to replace these expensive batteries if if can avoid it, and certainly want to know what are the "Best practices" to maintain batteries in storage.  I am thinking using a smart charger instead of just relying on built in inverter/charger may be required, as some others have recommended.  Another side question is that some people have recommended using a battery meter plugged in to a cigarette plug to monitor voltage. But wouldn't this do the same as just checking the battery voltage on the inverter (xantrex freedom) display?  I would like to do some boon docking this summer and so want to make sure batteries are up to the task.