To begin with let me say I have no financial interest in Lithium or any other type of battery supplier.
As most of you who have travelled very much in the last couple of years have no doubt seen is the increase in the number of people RVing and how it has in many areas overwhelmed the available supply of campsites. This coupled with new Federal rules forcing many campgrounds to be reservation only has made serendipitous camping challenging. I always enjoyed the ability of “first come/first served” to adjust your stay from one night to multiple nights if you found the area interesting and you needed more time to explore. Also if I wanted to adjust my route on the fly there were no reservation systems that made it more difficult.
To enjoy the less structured mode of traveling has forced many of us to utilize boondocking on BLM and National Forest areas and campgrounds. These frequently have little to no services available. This has encouraged me to look at electrical power improvements for my PC.
While our Phoenix units have the ability to supply power directly and/or charge our batteries from the generator I for one despise the noise. I am sure my neighbors like it even less than I do when running my generator.
My original two 6 volt Interstate flooded lead acid batteries were going on 6 year old. While still functioning I could tell they were loosing some of their energy storage capacity. I expected perhaps 1-2 years of remaining life albeit at reduced performance, which for the occasional user might have been fine. Since I was planning a prolonged trip with no anticipated shore electrical service I started reviewing my options.
I could replace with new flooded lead acid or the AGM lead acid but with little gain in terms of performance from what I originally had. I could continue with my old somewhat compromised batteries for however long they may last. It appeared Lithium Iron Phosphate was becoming more and more popular for RV and marine applications. I researched this forum, YouTube, other RV forums, and Lithium battery vendor websites in attempt to better understand the requirements and the plusses and minuses for Lithium. The Lithium Iron Phosphate chemistry is more stable than what is being used in electric propelled vehicles (Lithium-Nickel-Manganese-Cobalt) and is considered much safer.
For Lithium the number one hurdle for me was initial cost. When compared with AGM the Lithium cost typically runs about two to four times the initial cost per unit of rated energy storage capacity. When compared to useable energy storage amp hours the Lithium costs about two to three times the cost of AGM. The generally accepted guide for lead acid is to never discharge below 50% state of charge or battery life will be severely compromised whereas the full rated capacity for Lithium is typically stated as useable. Like many other claims I am sure this is arguable. Similar arguments on full recharge cycles are made. Lithium’s are claimed to have a 3,000-5,000 cycle life whereas Lead acid is on the order of 300-500 charge cycles thus only about 10% of the charge cycle life. If the Lead acid battery’s available recharge cycles was doubled the Lithium expected cycle life would still be three to five times greater. Bottom line is it appears that Lithium can be competitive on a cost per kilowatt hour over the life of the competing technologies.
As to the need to upgrade ancillary equipment (converters, chassis to house battery charging, battery monitor, etc.) this needs to be evaluated on a case by case basis. When I ordered my PC in 2016 I had a Progressive Dynamics 70 amp converter with Charge Wizard installed. Discussion with both the Lithium battery and converter supplier said it was acceptable. I previously installed a Victron battery monitor which also could be reused. The PC supplied chassis to house charge system worked though slower to recharge than the Victron DC to DC converter that is often recommended. I decided to give my PC installed system a try and reevaluate later based on my typical usage mode. Phoenix I understand when supplying their Lithium option relies on their standard alternator charge setup. So far while not optimum the PC system charges the Lithium batteries at a faster rate than the previous lead acid units. I may upgrade in the future but at this point I doubt it being justifiable based on my travel/camping style. So in my case no upgrading of the ancillary equipment hardware was required. However the programming of the solar controller and battery monitor did require adjustment. The battery supplier provided me with the new parameters for the programs.
After about a month and a half of camping without shore power I am very impressed with the Lithium batteries. Faster charge time means running the generator very infrequently and for a shorter periods, more efficient use of my solar array system, not being concerned that I need to get back to full charge everyday to prevent shortening battery life, not as concerned as to how much power I am consuming, no checking electrolyte level, more consistent voltage output, and hopefully longer battery cycle life (time will tell).
As to what I ultimately chose I went with two 100 ah 12 volt Battleborn Lithium Iron Phoshate batteries. They provide 200 ah of useable power. Being conservative I am not expecting to use the full capacity before recharge. They weigh less than half the previous flooded lead/acid golf cart batteries and easily fit the original PC slide out battery tray. I had multiple conversations by phone and email with Battleborn and another popular supplier. Battleborn batteries typically are premium priced. I have found their technical and commercial service was first class. The other popular supplier though cheaper I found was not very responsive and sorely lacking as to their technical support. Battleborn is currently running a sale though still premium priced they are becoming more attractive for anyone that truly relies on their batteries to make RVing more enjoyable. Battery technology is making major improvements in terms of performance and cost with more and more applications getting away from the dated lead acid designs and going to the new chemistries. On the flip side if your RVing means going to campsites with electrical hookup or you and your neighbors don’t mind the generator noise it is tough to beat the initial cost of two 6 volt GC2 flooded lead/acid golf cart batteries sold at Sam’s Club for about $90 apiece. It should also be pointed out that solar in the right conditions and/or frequent moves so as to allow the alternator to recharge the coach batteries can also minimize generator run time.
Initially at least for me there seemed an aura of complexity associated with the use of Lithium. What I am finding is yes there are some unique requirements for Lithium but probably no more complex than the requirements to properly apply lead acid technology, just different. If you are considering the Lithium option and are not familiar with Lithium requirements I recommend finding a reputable battery supplier with skilled application tech support that can and will guide you in the proper use of Lithium technology.
In conclusion there is no single “right answer” for every application. Several factors need to be considered when choosing a battery system.
Sorry for the lengthy post but I hope this might be helpful to anyone needing for whatever reason to replace their current coach batteries. I would also be curious what others that have already made the switch to Lithium have found.
