Lead Acid Vs Lithium Ion
LFP batteries don't have to get back to a hundred% SoC regularly, like lead acid does. In truth, maintaining LiFePO4 cells at a hundred% SoC can really negatively impact cycle life.
Not needing to get back to 100% SoC, on a routine foundation, is a major win for LFP. When we come again from a cruise, and our battery is at 50% SoC, I don’t care.
Nevertheless, it's common to cost a 12 volt a 4-cell series pack with a lead acid battery charger. The maximum voltage of these chargers, whether or not AC powered, or using a car's alternator, is 14.4 volts. This works nice, however lead acid chargers will lower their voltage to thirteen.8 volts for the float cost, and so will usually terminate before the LiFe pack is at 100%. For this purpose a special LiFe charger is required to reliably get to a hundred% capability.
This serves to allow for the CV stage to be safer for a slightly longer length. Most lead acid designed cost sources can maintain the absorption voltage stage greater than lengthy enough to cause long run injury or eat into some cycle life capability of your costly LFP cells.
In order to navigate out of this carousel please use your heading shortcut key to navigate to the following or previous heading.
In order to fend off the effects of sulfation we have to cost them to 100% SoC as often as potential. This proves very tough for many cruisers except your boat resides at a dock after each use or sits on a mooring with an adequate photo voltaic system.
Some LFP producers are now beginning to understand this level, when promoting into a lead-acid charger setting, and have reduced really helpful max charging voltages accordingly. The high quality of the cells used contained in the battery additionally play a serious position as to how properly they deal with fixed voltage being held longer than is important. We know the Achilles heel of lead acid banks on cruising boats is nearly always sulfation.
LFP batteries really choose to take a seat at 30-sixty five% SoC rather than at one hundred% SoC. As I mentioned earlier, this can be a psychological paradigm shift owners of LFP might want to overcome in our human conduct/thinking round our batteries. The lead acid mindset of one hundred% SoC usually or continual floating in the upper SoC register might be finest to be mentally reprogrammed. A LiFePO4 battery may be safely overcharged to 4.2 volts per cell, however larger voltages will begin to break down the natural electrolytes.
These cells and batteries not solely have high capacity, but can ship high power. High-power lithium iron phosphate batteries are actually a actuality. It has been proven that higher charge voltages, with all Li chemistries, ends in shorter cycle life. Essentially larger charge voltages result in more electrolyte oxidation clogging the negative plate.
While the capacity could look good for a time frame the cells finally fall of the proverbial cliff. In NMC cells cycle life degradation was accelerated as charge voltages had been pushed higher. It just isn't however just max voltages that have an effect on the cells it's time at voltage. In the checks above the cells were merely cost “TO” the upper voltage but with the lead acid chargers we use voltages are “HELD” at a gradual voltage for a time frame.