In addition to the price, what are the disadvantages of lithium iron phosphate (LiFePO4) batteries?
If the price of lifepo4 comes down, will no one buy the lead-acid battery?
asked
What are the disadvantages of lithium iron phosphate (LiFePO4) batteries?
Main disadvantage for me (beside cost) is the inability to charge at low temperatures (below freezing). Also not quite ideal is the rapid deterioration at high temperatures (30°C+ which is common for several months in summer). While that's somewhat identical to lead batteries there's still the cost factor to consider. There's a difference if you (inadvertently) ruin a 200€ battery vs 2000€ battery.
I found that some lifepo4 batteries can charge below freezing temperatures, it can be charged at -20℃.
Whatever promises I've seen in that direction is that there's an integrated heating element to bring the battery to operational temperature before any charging actually begins. Not quite the most efficient use of limited power available on boats and motorhomes with inevitably small solar panels where freezing temperatures are also quite likely to occur. On days when you're lucky to be making 30W you're not going to get much battery heating going on, much less have anything left over to charge.
There's two parts to consider: the cells themselves, and the (more or less) mandatory need for a battery management system if its not built into the battery.
The BMS adds to the cost and complexity (its by no means a massive hurdle, but not trivial either).
This below just makes for good reading. LiFePO4 vs NCM. As for it vs LA, it may be worth noting sometimes depending on the battery, they cannot simply be connected in serial or parallel. https://lghomebatteryblog.eu/en/this-is-why-ncm-is-the-preferable-cathode-material-for-li-ion-batteries/
I don’t know if my idea is correct.
Now the technology of BMS is mature and the problem of low-temperature charging has been solved (although the charging rate is slow, at least it can be supported), also some lifepo4 batteries have supported multi-series and -parallel, and monitor the status of the battery. So, besides the price, why not use lifepo4?
It depends what your requirements are what battery solution will be best for you. In my opinion, If it is not for daily self consumption, Li may not be for you.
Emmm...why it is not for daily self consumption? Because of the price?
price is always a factor in real systems. Lithiums allow a deeper draw down without additional degradation (compared with LA chemistry).
Without putting your question into some context, any and all answers are correct - is weight an issue for your application? Do you have a fixed space to which certain AH has to be catered for? Or can you fix the AH and live with space and weight that comes with it?
Can lead-acid batteries are easily connected in series and parallel without BMS?
Is there a way for BMS to buy (on Amazon?) off-the-shelf?
or am I looking for a custom one?
May I suggest you take some time to Bing and view the wealth of material on the topic out there. A simple search could answer a lot of your questions e.g can you buy a BMS off the shelf. I find product manuals and user reviews experiences a very valuable source of information.
You have not explained what the application is for the LiFePO4 batteries. If there are automotive alternators in the system then they add additional expense to protect them when the LiFePO4 reach 100% SOC
I am in the process of upgrading my 25 yr old 12v offgrid system. I've settled on a Quattro 48/5000/70 and 450AH of Lithionics batteries. The batteries have a heater installed in the core that is powered by 12v which the BMS turns on at 35F and off at 40F. My batteries are in an unheated building. The heater can be turned off, then the BMS will prevent charging below freezing but allow discharge to -4F. I live in maritime Alaska so out temperatures are not extreme, 30F the mean temp in January. The heaters use about 250w so during periods with low solar I plan to turn them off, then when there is solar or I have to charge, to run a Honda 2000i into AC2 and have the heater on the AC2 out. This should warm the batteries and run my loads . I'll have a 12v power supply and relays to effect that. Once the batteries reach safe temp I can run the big generator and use solar input to charge. The big generator is in the unheated building with the batteries and will put heat there.
It seems a complicated route, but I hope the advantages of LiFePO4 will make it worth the effort. I live on a remote island hoestead and am used to monitoring/managing our power. I'll write again in the spring and give results from the setup.
When comparing LefePO4 vs NCM, LifePO4 wins hands down in real world independant test -reports provided here https://batterytestcentre.com.au/
