This might be a bit of a ramble, but i thought it might be helpful to some people who are about to set-up a completely off-grid system.
Where i live, there is no grid connection. I am surrounded by hundreds of properties that rely on off-grid systems for their electricity needs. My initial system was installed when we moved to our property in 2012. It was the first LiFePO4 system in the area, and most people were sceptical at first but after five or so years i had a steady stream of people coming to me for advice on setting up replacement systems for their failing units.
After a few years our power requirements increased dramatically, and i installed an additional completely independent system to cover secondary loads. This system can be switched to charge the primary batteries or power the primary load. I started helping other people install systems, and left their original (most often lead acid) systems in place, to provide trickle charger via AC chargers to their new LiFePO4 systems.
I had been advised by my cell manufacturer to not let my cells exceed 40degC, and have always airconditioned my battery room. Other people in the area had professionally installed LiFePO4 systems (mainly Pylontech) and they commonly fail around the 5-7 year mark due to heat exposure. The failure mode is that they start to suffer from voltage drop under load. I have found these systems will trip the BMS if they are loaded at 5kw (for example), but will happily provide 80% capacity if they are only loaded at 1kw. There are a few of these systems that have been like that for many years, with the Pylontechs being used to trickle a 1kw charge overnight into the new system. (thus allowing for a much smaller battery on the primary system).
My suggestion for anyone putting in a new off-grid system is to make sure that the area you have set aside for your system is big enough for two complete systems even if you don't initially purchase them. Ultimately, when you need to replace your system you can build your new system in place and either use your old system as a trickle charge additional capacity - or decommision.
I've seen first hand the stress that can occur due to power system failure in a completely off-grid system. (one of my generators has done more hours at other peoples houses than mine) When you design a system, have an answer written down for what you would do in the event of a component failure (have this answer for every component). Consider starting with two completely independent systems (these can be auto switched to your critical loads).
Where i live, there is no grid connection. I am surrounded by hundreds of properties that rely on off-grid systems for their electricity needs. My initial system was installed when we moved to our property in 2012. It was the first LiFePO4 system in the area, and most people were sceptical at first but after five or so years i had a steady stream of people coming to me for advice on setting up replacement systems for their failing units.
After a few years our power requirements increased dramatically, and i installed an additional completely independent system to cover secondary loads. This system can be switched to charge the primary batteries or power the primary load. I started helping other people install systems, and left their original (most often lead acid) systems in place, to provide trickle charger via AC chargers to their new LiFePO4 systems.
I had been advised by my cell manufacturer to not let my cells exceed 40degC, and have always airconditioned my battery room. Other people in the area had professionally installed LiFePO4 systems (mainly Pylontech) and they commonly fail around the 5-7 year mark due to heat exposure. The failure mode is that they start to suffer from voltage drop under load. I have found these systems will trip the BMS if they are loaded at 5kw (for example), but will happily provide 80% capacity if they are only loaded at 1kw. There are a few of these systems that have been like that for many years, with the Pylontechs being used to trickle a 1kw charge overnight into the new system. (thus allowing for a much smaller battery on the primary system).
My suggestion for anyone putting in a new off-grid system is to make sure that the area you have set aside for your system is big enough for two complete systems even if you don't initially purchase them. Ultimately, when you need to replace your system you can build your new system in place and either use your old system as a trickle charge additional capacity - or decommision.
I've seen first hand the stress that can occur due to power system failure in a completely off-grid system. (one of my generators has done more hours at other peoples houses than mine) When you design a system, have an answer written down for what you would do in the event of a component failure (have this answer for every component). Consider starting with two completely independent systems (these can be auto switched to your critical loads).
% off-grid for the last 3.5 years at 7,000' in Colorado. We are currently slow building (just wife & I most days) a 4,000' new home that we started last summer. (We are dried in.) I often tell people that "The rule of thumb for off-grid living, is that you need a backup for your back up."
