Once again we find a very well produced test confirming what we’ve known on the channel, for the past few years. Lead Acid battery manufacturers have deceived consumers with false specs and claims in regards to amp hour ratings, watt hour ratings, and their reduced performance and capability caused by Peukerts Law.
Peukerts Law demonstrates mathematically that as the rate of discharge increases on lead acid batteries, the available capacity of the battery is reduced. Higher load, lower capacity. A 100 amp hour battery will act more like a 50 amp hour battery, when repeated high current loads are applied to the battery. As an example, think about repeatedly calling CQ during field day, while using a 100 watt radio or station amplifier powered with a lead acid battery.
The effect of Peukerts Law can certainly be reduced by adding parallel sets of lead acid batteries. The caveat is the additional cost. For example, we can reduce Peukerts effect when applying a heavy load, by sharing that load between 2x 12 volt batteries in parallel. The same is true for 2x 6 volt flooded batteries in parallel with an additional set of 6 volt flood batteries in parallel, making a 12volt set. The capable 12 volt battery set just doubled in price, but still won’t achieve LiFePO4 performance or capabilities.
The issue misrepresented by the lead acid battery industry is one of calculating cost of ownership versus expected performance. To be fair, a lead acid battery is perfectly fine for powering our starter motors. It is anything but “fine” for powering current hungry amateur radio equipment.
The following video is from the YouTube channel Mortons on the move. Tom and Cait detail their Off Grid RV experiences on their channel. If you are interested in that sort of thing, please do subscribe to their channel. This video explains in great detail the testing carried out to understand the cost and performance realities of lead acid versus Lithium Iron Phosphate (LiFePO4) batteries. One brand of LiFePO4 battery was tested against 4 brands of lead acid batteries. The lead acid batteries were also tested and compared against each other. There is no scam, no trickery, just good quality testing and documentation. The raw data of their testing is also available from their website, for those interested in validating the findings. Links are below the video.
For the test results head over to the Mortons on the move website ( https://mortonsonthemove.com/best-rv-battery-test-results/ )
As always, I am certain there will be a sh*tstorm of hate for calling out the lead acid battery industry. The thing is it is not about “how we feel”, or our perception of “getting a good deal”. It is about giving operators the best information possible, so that they can choose the best portable or fixed location battery solutions with lowest cost of ownership. I don’t care how this makes anyone “feel”. The goal is presenting facts and nothing else. How one interprets or acts on these facts, is entirely ones own business. I for one stopped being cheated by the lead acid battery industry, many years ago. As such, I understand there is no scenario where a lead acid battery has better performance or cheaper cost of ownership, when deployed as an auxiliary battery storage. The exception might be when deployed as a starter battery (maybe).
One exception to lead acid < lifepo4 I found was if your concerned about emp / solar cme, I have not found a way to harden the BMS of a lifepo4. Sure, you could have spare bms’s tucked away, but then it becomes a consumable with a finite supply. Do you swap it right away, or do you wait a little while? How long is a little while? Not trying to spark debate, just something to ponder. Other than that, lifepo4 all the way.
That’s a great point! Remember though, the BMS is not a requirement. It’s there to prevent mishaps yeah, but the individual cells when combined, will still work happily together.
Absolutely agree. I have to wait till I kill this set of AGM to switch the shack over… but my “84ah” bank might last 3 hours at <10a above useable voltage. Might as well have a 35ah lifepo4…