Converting to Lithium Ion batteries ????

[Dave'n'Kim]

Hi Please forgive me - NEWBIE ALERT - joined the forum in 2012 but don?t use them (reasons too boring).
New Post addition Sept 2018 - Just wanted to mention I have recently installed a 500AH Elite lithium system in our 5th wheel with 6 solar panels and if anyone considering doing the same wants to read the story, here?s a link if I?m allowed to put it here?!  Sorry if I?m breaking any rules, or off-topic, I just hope it might be of help to people!  http://www.kimartanddesign.com/Daves/JourneyToLithium.htm

 

[solarman]

Hi Please forgive me - NEWBIE ALERT - joined the forum in 2012 but don?t use them (reasons too boring).
New Post addition Sept 2018 - Just wanted to mention I have recently installed a 500AH Elite lithium system in our 5th wheel with 6 solar panels and if anyone considering doing the same wants to read the story, here?s a link if I?m allowed to put it here?!  Sorry if I?m breaking any rules, or off-topic, I just hope it might be of help to people!  http://www.kimartanddesign.com/Daves/JourneyToLithium.htm

well I read your blog and all I'll say is I would not advise anyone here to copy such a system.
if you need technical reasons then please pm me.

 

[solarman]

Just had a nice chat with these folks, just a curiosity/info call.

Basic, they have a 12V, 480AH Lithium that sells for roughly $5K including battery management system. They have had this battery in the field in an RV for about 5 years, getting cycled down to about 5% routinely (so VERY heavy usage). After 5 years battery has degraded to about 80%; they figure they have about one more year of life.

These field users previously had AGMs which they were only getting two years out of (again, I think they are cycling the daylights out of them). Compared to Li-ion they're now getting triple the life, so from their perspective they might be close to breakeven.

Generator run times are substantially less as batteries can take a full charge almost until full. Even so, cost is still triple lead acid so seems like it will be quite awhile before Li-ion is tempting for those getting more life out of their lead acids.

cycles down to 5% tells me they do not know what they are doing.

one can only justify LFP for special circumstances, they are not cost effective for most normal RV use

 

[AStravelers]

cycles down to 5% tells me they do not know what they are doing...................

Yep, taking Lithium down to 5% is like taking lead acid down to a SOC of 50% or 40% most of the times you use them.  That will greatly reduce their life. 

Additionally taking lithium down to 5% is very close to tripping the low voltage cutoff.  If you go that low and you get distracted and forgot to very closely monitor your usage or start your charging the cutoff will trip.  Now you have lost all 12V and nothing in the RV will work. No fridge, heater, lights, nada, nothing.  Once you trip your low voltage cutoff, there are steps to take to recover.  You generally just don't start the generator and start charging.

 

[AStravelers]

....................one can only justify LFP for special circumstances, they are not cost effective for most normal RV use

I could agree about "special circumstances" if that includes people who do lots of dry camping or boondocking, such as 45 to 150 days a year.  I would also add to that the folks who do quite a bit of dry camping and just want the convenience of not needing to to get your batteries to 100% charged frequently as well as not going below 50% SOC.  Then there are the people who need more power, but would overload the RV with heavy lead acid batteries. 

Besides, if one wants to talk about cost effectiveness, only a small number of RV owners can cost justify their RV over staying in hotels and driving or flying to their destination.

 

[solarman]

well I read your blog and all I'll say is I would not advise anyone here to copy such a system.
if you need technical reasons then please pm me.

ok, i'll admit to being a bit harsh here, your diy efforts are quite good, but on first look at the setup i noticed
one serious and potentially dangerous issue with the cable size and lugs. pm me and i'll go through the issues.

 

[ALLOY]

I'm seeing Roadtrek now offering a super boondocking RV with a load of Lithium Ion batteries and tons of solar.  The reference to being able to quickly charge the batteries from the van generator (if solar isn't enough) is also positive.

Can an older RV with standard lead acid batteries be converted to Lithium Ion?  What would it require?

I'm guessing there are plus and minuses.  Thoughts?

I didn't see an existing thread on this or related topic but point me if I've just cluttered the forum with a duplicate topic.

Thanks

The performance of Lithium is far superior to FLA but only if one makes use of the performance. For some not having to check the fluid level in a FLA is enough. 

Charging (not discharging) Lithium below 35F reduces the life expectancy and warranties do not match life expectancy claims. Elite Battery is a 1 year warranty while Battle Born is 3 years.  The Crown 960 FLA (equivalent to 650Ah of Lithium) bank I purchased for $930 in the spring has a 3 year warranty.

The cost of used cells is appealing but there is a greater risk of cell damaged.  A second thought should be given to having these in a living space.

 

[shorts]

Just an FYI - Battle Born now has a 10 year warranty even for those who have already purchased batteries in the past.

Vicki