One of the newer chargers. I got a Pronautic 1220P for my start battery for some reason, and it has a setting on it for LiFePO4.
I will send you a PDF of the manual off list. Bill Coleman Entrada, Erie, PA From: james taylor via CnC-List [mailto:cnc-list@cnc-list.com] Sent: Tuesday, May 31, 2022 7:20 PM To: Stus-List Cc: james taylor Subject: Stus-List Re: Batteries again Another question that haven't seen in this discussion. What battery charger do you need for this type of battery? My charger has setting for flooded, sealed and AGM, and I haven't seen many chargers that mention LiFePO4settings. On Fri, May 27, 2022 at 7:19 PM Joe Della Barba via CnC-List <cnc-list@cnc-list.com> wrote: Quick battery facts: An ideal battery is like a water tank. It holds X amount, can be filled as fast as you want or as slow as you want, and likewise for emptying the water. No matter what, you get 10 gallons out of a 10 gallon tank. How all types of lead-acid batteries fail in being perfect: 1. Peukert Effect – A 200 amp hour battery might last 250 hours if only drawing one amp and maybe one hour at 100 amps. 2. Charge efficiency – Not all the electricity that goes in gets stored, some amount is converted to heat, off gassing, etc. 3. Cycle life – A 200 amp hour battery eventually declines to a lot less than 200 and then is dead. Battery manufacturers supply graphs of depth-of-discharge vs. lifespan of the battery. A battery discharged to 80% and recharged carefully to 100% might last well over a thousand cycles. One discharged to 0% and recharged might last 10 or 20 cycles or maybe 1 cycle if it was a starting battery. Most cruisers figure on 50% depth-of-discharge as the limit for a good lifespan. What this means is a 200ah lead battery is good for 100ah if you want it to last AND have a way to get it all the way back to 100% easily. Many people figure on cycling between 50% and 90% or so. The fuller a lead battery gets, the slower it charges. In contrast, a lithium battery is a lot closer to the ideal. The charge efficiency is high, the Peukert Effect doesn’t really exist for them, you can charge them fast if needed, and their lifespan is good to 80% discharge. A 200ah lithium battery is good for 160ah useable capacity, not the less than 100 that is the practical useable capacity of lead battery of the same nominal rating. Joe Della Barba Coquina C&C 35 MK I Kent Island MD USA From: Bill Coleman via CnC-List <cnc-list@cnc-list.com> Sent: Friday, May 27, 2022 4:27 PM To: 'Stus-List' <cnc-list@cnc-list.com> Cc: Bill Coleman <colt...@gmail.com> Subject: Stus-List Re: Batteries again So Dave, would the SOK Battery 206Ah 12v LiFePO4 Battery Solar Battery be an equivalent swap-out for a Lifeline GPL-8DA 12 V 255 AH Battery? This is a little confusing (and intimidating) for the non-initiated . . Bill Coleman Entrada, Erie, PA From: Dreuge via CnC-List [mailto:cnc-list@cnc-list.com] Sent: Thursday, May 26, 2022 3:24 PM To: cnc-list@cnc-list.com Cc: Dreuge Subject: Stus-List Re: Batteries again Dave, As I mentioned in previously replies to the list, it no longer makes any sense to buy lead acid batteries(i.e. flooded, gel, or AGM) for a house bank. For lead acid, the AH capacity is highly dependent on the current load due to the Peukert Effect. Deep cycle lead acid batteries are rated at C/20. For a 100AH rated battery, this is 100AH/20H = 5A. This is often called the 20H rate, i.e. 5A * 20H = 100AH. If the actual load is 20A, then the same 100AH rated lead acid battery would only provide 60AH (or 10AH at 100A). And worse, one should only use 50% of a lead acid battery’s capacity as going below 50% substantially degrades the battery lifetime. This means that a 100AH lead acid battery has an effective 50AH @ 5A (or 30AH @ 20A). Let’s assume a 100AH lead acid battery price of $264 (the average of the Amazon prices), then 2 batteries would cost one $528 and one would get an effective 100AH (50%*200AH) at 5A loads. Now, the price of LiFePO4 batteries have come way down in the last few years and their performance and lifetimes are a magnitude better. A 100AH LiFePO4 battery is typically rated at 1C. That is they can deliver 100AH at 100A for 1H(or 5A at 20H or 20A at 5H). They can also charge at amps up to 100A which is impossible for a lead acid battery. And LiFePO4 batteries live 5 times longer. That is, one would expect to replace 5 sets of lead acid batteries before replacing a LiFePO4 battery. Yes, LiFePO4 batteries are more complex as they require a battery management system (i.e. BMS), but there are companies which provide 12V drop in replacements with the BMS built internal to the battery. Top companies like Battle Born sell a 100AH LiFePO4 for $874 and provide a 10yr warranty. Renogy sells a 100AH LiFePO4 for $765. A company, CurrentConnected.com, sells a SOK 100AH LiFePO4 battery for $569 and it has a 10 yr warranty! YouTuber Will Prowse rates the SOK as the best value LiFePO4 12V drop in replacement (see https://www.mobile-solarpower.com/lithium-batteries.html). There are a plethora of cheaper 100AH LiFePO4 batteries that can be found on Amazon, Ebay, AliExpres, …, but one gets little service and limited warrantees, so I would recommend avoiding these. Rather than buying 2 100AH lead acid batteries for $528 at a total weight of 140lbs(70lbs each) , one could just buy 1 100AH LiFePO4 for $569 weighing only 28lbs and get a better performing battery. That is basically the same price. If one takes into account the increased lifetime, the saving is HUGE! If one builds their own DIY LiFePO4 battery, the savings is much much greater. Last year I replaced 2 100AH lead acid batteries with one DIY 560AH LiFePO4 battery for a little over $900 (see my blog link below). The DIY LiFePO4 battery occupies the same location and physical space as the previous 2 lead acid batteries, it weighs much less (95 lbs vs 125 lbs), but has 5 TIMES the capacity. I recently gave a talk on off-grid solar systems a local amateur radio society meeting. The discuss the battery as the heart of the system and make the case for LiFePO4 batteries. My slides from the talk are available on my blog: https://svjohannarose.blogspot.com/2021/10/solar-off-grid-system.html Also, the details of my DIY 560AH LiFePO4 are posted at the link below which includes details about alternator charging. https://svjohannarose.blogspot.com/2021/06/adding-new-lifepo4-to-house-battery.html
