twistedtree
Guru
I am in the research and design stage of a lithium battery bank, and am looking for suggestions on battery manufacturers and BMS systems. This is for an off grid house, which is basically the same as a boat that's fast aground. Assuming success, I will then roll out a similar system on an actual floating boat.
The existing off grid battery system is flooded lead acid, 1300ah, 48V, so I get about 650ah of usable capacity, but it is reaching the end of it's life.
The lithium bank will be LiFePO4, and I'm targeting 300-600ah.
I have looked at a couple of the packaged systems like Victron and Mastervolt, but they are too much of a cost premium (3-4x) over buying cells, and a BMS, so I'm planning on the later.
My first question is about what battery manufacturers I should consider. I have looked at CALB and Winston so far, but am sure there are others. I want a vendor with some track record, or at least as much as anyone has in this field. Who else should I consider?
The second questions is about a BMS. I have seen arguments for varying levels of monitoring and active management. At a minimum, string voltage measurement with charge and load disconnect seems sensible.
Individual cell voltage monitoring would be taking the next step, and would detect cell imbalance that could cause a single cell to run too high or too low before the whole string voltage monitoring detects a problem.
Next would be automatic cell balancing. It's a nice feature, but many people argue that if you manually balance the cells initially and run the pack between 20% and 80% state of charge, then re-balancing is unnecessary. And if you are monitoring individual cells, at least you can detect when re-balancing is required and do it again manually.
And last is temp monitoring. I don't expect this will be much of an issue for the house where the battery location remains a constant 50-65 deg year round. But on a boat, higher temps are likely, and many LiFePO4 batteries have an operating temp of 40C or below.
So what recommendations do people have for a BMS?
OK, that should be enough to get the discussion started.
The existing off grid battery system is flooded lead acid, 1300ah, 48V, so I get about 650ah of usable capacity, but it is reaching the end of it's life.
The lithium bank will be LiFePO4, and I'm targeting 300-600ah.
I have looked at a couple of the packaged systems like Victron and Mastervolt, but they are too much of a cost premium (3-4x) over buying cells, and a BMS, so I'm planning on the later.
My first question is about what battery manufacturers I should consider. I have looked at CALB and Winston so far, but am sure there are others. I want a vendor with some track record, or at least as much as anyone has in this field. Who else should I consider?
The second questions is about a BMS. I have seen arguments for varying levels of monitoring and active management. At a minimum, string voltage measurement with charge and load disconnect seems sensible.
Individual cell voltage monitoring would be taking the next step, and would detect cell imbalance that could cause a single cell to run too high or too low before the whole string voltage monitoring detects a problem.
Next would be automatic cell balancing. It's a nice feature, but many people argue that if you manually balance the cells initially and run the pack between 20% and 80% state of charge, then re-balancing is unnecessary. And if you are monitoring individual cells, at least you can detect when re-balancing is required and do it again manually.
And last is temp monitoring. I don't expect this will be much of an issue for the house where the battery location remains a constant 50-65 deg year round. But on a boat, higher temps are likely, and many LiFePO4 batteries have an operating temp of 40C or below.
So what recommendations do people have for a BMS?
OK, that should be enough to get the discussion started.
