It’s a long shot but maybe someone here can shed light on best way to protect these lithium ion batteries and protect myself and Motorhome from potential fire. If there is a relatively safe way.
I have 21 Generation 2 Nissan Leaf modules. Not new, they were used. They have been here 7 months now and have dropped slooowly from 4.0 volts per cell to 3.6 volts. So each module now has 7.2 volts as there are two pairs of cells in series and two pairs of cells in parallel in each module, 2s2p configuration. The inverter/charger I have currently is 24 volts in a functioning solarenergy system with some lead acid batteries. I also have a 12 volt inverter/charger I could use. I had considered switching to 12 volt as it’s the same voltage as the Motorhome charging system.
I started out reading about spendy bms systems like Orion, Batrium, and rec. Then found a less spendy bms by Energus and even less by Chargery. I’m leaning towards trying a Chargery bms and Charger. Has anyone tried them ? For now I’m thinking of just charging the Leaf batteries from the existing solar energy system using a Chargery adjustable charger and bms. Total cost around $350 give or take. Much less than the others. I realize it’s not as efficient with the extra charging conversion step but I’m not ready to install the Leaf batteries permanently yet. I may use them in an electric scooter project?
Also I’m wondering if I should just use cheap battery protection boards for the time being instead of messing with a bms. Maybe later get the bms when I know exactly where I’m installing them. I find the protection boards to be confusing. There’s so many models available from China. Which boards work properly as there’s 4 cells, 2s2p, in each Leaf module and only three terminals. I got stuck on a mental block on that wiring puzzle. Individual cells with accessible terminals would be much simpler to understand.
What happens to a sealed 2s2p module if one cell goes bad. Say it starts dropping voltage faster than others? I guess this is one reason why these batteries are not as popular as Tesla. Because they are sealed and a different chemistry?
I myself use a Tesla Model S battery module. I have for over a year been running this with a cheap BMS.
I believe I would look into the BMS this guy is using, he uses it for Chevy Volt batteries.
posted 1 year ago
Hi Mart and whomever,
I joined your battery group for grins and as I’m getting ready to play with these Leaf batteries again. Thanks for the heads up. Maybe I’ll learn something worth sharing. I was sidetracked by other stuff all Summer but figure the rainy season is good for tinkering on the electrical and electronics.
So what I’m going to do is clear some space and install a desk/workbench.
It’s been a few months since I searched the online battery videos for information about Leaf batteries. There was a few videos about building a custom Leaf storage battery but I had not found one describing the BMS. Journey to this Morning mentions he uses REC bms but I did not see one about how he does it.
Maybe those more knowledgeable about electronics will chime in.
What are the different types of BMS? What are the advantages and disadvantages?