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Mike,
Great article on the expion360 lithium conversion you did on your camper. I am in process of converting my Lance 820 short bed camper to lithium batteries and appreciate all the info you put out for everyone!! I wanted to point out and get your take on the load test chart gopower has on their lithium battery section which shows the expion360 120 AH battery has only 96 usable AH verse the Battleborn which has a 100% usable AH. Could you comment on why it’s rated at only 80% of 120 AH rating? Thanks again!!Gee, I don’t know. I have no idea why a competitor, who also makes lithium batteries, would have lower ratings for a competitor’s lithium batteries. 🙂 I wouldn’t put much stock into it. My Expions work great, no problem with them at all.
I did try and find what you were looking at on their website but couldn’t find it. Do you have a link?
I will venture a WAG here and posit that the differences between these various manufacturers offerings has less to do with the chemical composition differences of the LiFePo4 cells (which this has been roughly standardized) and lots more to do with the various proprietary strategies designed into their BMS system, thereby narrowing the breadth of discharge (maximum available amps) to prevent (or greatly reduce the possibility of) the formation of damaging dendrite formation and to extend longevity…
This should be of concern to all manufacturers, so my guess is that Expion has merely chosen a more conservative parameter.
On Dendrites:
Phil
Phil thanks for your input. If The load test is accurate seems like Expion should be more conservative or accurate on their rating.
Do you use lithium batteries in your rig? Also I have not read of any lithium phosphate type batteries exploding or catching on fire, have you? I leave my dog in my camper while I ski so I would not want to add a risk of fire while I’m out shredding!!From all that I’ve read, the laptop (et al) fires that occurred with lithium had to do with with a ‘hotter’ chemical mix that relied on cobalt which provided even greater power density (e.g. uber smaller batteries), but made charging parameters far more critical, which if violated led to formation of dendrites, thus the combustion hazard.
The lithium RV type batteries of your concern (Lithium-Iron-Phosphate) do not contain cobalt, and are much more forgiving – charging algorithms while important are not nearly as critical – in fact in many cases (depending on one’s particular OEM charger type) there may not even be a need to upgrade to a different charger type.
The other important safety feature is the proprietary multi-function BMS system that a manufacture designs which also prevents charging below say 32df (in most cases – though the battery can still be discharged down to about 0df < >, however, indoor placement or a warming blanket can mitigate this issue) while yet another issue (as previously mentioned) is by preventing deep excursions into the battery’s extreme lower capacity limit, as well as prolonged over-charging – I believe this is most likely the reasoning used by Expion…
As far as charging voltages go, check with your manufacturer, but in our case (using one Aims Li 100a/hr) 14.4 to 14.6 Bulk mode at about 60% ampacity works well to 100% SOC (state of charge), thereafter with charger switching to float at about 13.x, though float mode is not necessary or harmful – BTW, many charger algorithms for ‘wet-cell’ already come this way (but verify first…). It should be noted too that lithiums should not be equalized – the balancing of individual cells is the job of the BMS (battery management system)…
With the right charger (and/or solar charge controller), and by simply following the manufacturer’s recommendations you should have no problem whatsoever with LiFePo4’s, and benefit from the fact that voltages remain nearly constant throughout the entire discharge range…
Case in point, once when running a Coleman air conditioner (via an inverter) we inadvertently lost track of time until we suddenly realized that the battery was down to a very lowly 6% SOC (Per Victron), though the compressor was still running along quite perfectly!!…As I said this was because of our own oversight and not a recommended practice – lol!
JMO, Phil
Thanks Phil for all that knowledge!! I’m going with 2 100ah battle borns with Parallel Victron 25 amp chargers and Victron mppt 20 amp controller with 270 watt solar panels. Prob go with Victron battery monitor too although I like expion360 monitor with all the parameters on a single screen. Thanks again brother and Happy camping !!
Terry, Sounds like a pretty sweet set-up Sir – you won’t be disappointed !!…BTW, though still using my faithful 3yr old golf cart 6v’s (with occasional use of the air cond), when I do make the switch to Li, I really like the idea Mike posted about the Expion 360 Lithium Power-mod blanket…In my case, locating the Li battery inside the camper’s interior does not seem too viable of an option…I’ve always been able to get by with just the two GC’s (roughly 100 usable amp/hrs), so can hardly imagine the uber luxury of having a whopping 200 available amp/hrs with nearly no drop off in voltage – Dang!!
Good luck, Please keep us posted!
Phil
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