filippomasoni
New Member
Hello, I've ordered 8 280ah cells from Amy, and I should receive them in the next 2-3 weeks.
I have a few related doubts that I couldn't find answers to. I've heard and watched many videos about compression and top balancing but got confused on a few things.
1.
I'm planning on compressing the cells with the classic threaded rod and plywood which will serve as my battery enclosure as well, with handles for easier transportation. I want to top balance the cells first but I would like to avoid uncompressing them at 100% SOC to rearrange them in series because in theory losing the compression is not good and would render the compression useless. I could arrange in the final configuration and make some wires to parallel them, (don't need to be big wires in theory because I'll charge at a max of 20A and it's only 10cm). Otherwise, I have to discharge them at 50% after top balancing and I'm not sure how I should do that.
2.
How should I check for capacity? Should I buy one of those capacity testers for single cells and run that for each? (will take forever) or just trust the quality of Amy's cells and run a capacity test with the BMS at 24V? If I let the battery go to 0% to do a capacity test, do I run the risk of damaging it since it's advised to only go to about 20%? Or is that recommended only for regular daily use and if done only one time it's not an issue?
3.
Do I need one of those variable DC power supply or I can get by with one of these: https://shop.gwl.eu/Chargers-6V-to-36V/Charger-3-6V-20A-for-LiFePO4-cells-1-cell.html?cur=1
I'd like to have a small power supply, that works all over the world (AC 100-240V 50-60Hz) that I could keep in the camper in case of need and I don't like those bulky chargers. I'd also get this: https://shop.gwl.eu/Chargers-6V-to-...attery-charger-27-6V-21A-600W.html?cur=1#tab1 as my shore power charger, that also works worldwide.
4.
Finally, I'll probably need to store the battery for 4-5 months before I can start the build in my camper. I know I should keep them at 30-50% SOC, what do I need to discharge them to that desired percentage?
Little off-topic opinion:
In reality, I'm not too concerned with compressing because even without it they will probably last up to 7 years and I'm sure we'll have much more efficient technology by then and they will be obsolete. But I anyway need to make an enclosure since they will stay in a camper so might as well make a compression enclosure. If they last longer it will be better for the environment as well I guess.
I have a few related doubts that I couldn't find answers to. I've heard and watched many videos about compression and top balancing but got confused on a few things.
1.
I'm planning on compressing the cells with the classic threaded rod and plywood which will serve as my battery enclosure as well, with handles for easier transportation. I want to top balance the cells first but I would like to avoid uncompressing them at 100% SOC to rearrange them in series because in theory losing the compression is not good and would render the compression useless. I could arrange in the final configuration and make some wires to parallel them, (don't need to be big wires in theory because I'll charge at a max of 20A and it's only 10cm). Otherwise, I have to discharge them at 50% after top balancing and I'm not sure how I should do that.
2.
How should I check for capacity? Should I buy one of those capacity testers for single cells and run that for each? (will take forever) or just trust the quality of Amy's cells and run a capacity test with the BMS at 24V? If I let the battery go to 0% to do a capacity test, do I run the risk of damaging it since it's advised to only go to about 20%? Or is that recommended only for regular daily use and if done only one time it's not an issue?
3.
Do I need one of those variable DC power supply or I can get by with one of these: https://shop.gwl.eu/Chargers-6V-to-36V/Charger-3-6V-20A-for-LiFePO4-cells-1-cell.html?cur=1
I'd like to have a small power supply, that works all over the world (AC 100-240V 50-60Hz) that I could keep in the camper in case of need and I don't like those bulky chargers. I'd also get this: https://shop.gwl.eu/Chargers-6V-to-...attery-charger-27-6V-21A-600W.html?cur=1#tab1 as my shore power charger, that also works worldwide.
4.
Finally, I'll probably need to store the battery for 4-5 months before I can start the build in my camper. I know I should keep them at 30-50% SOC, what do I need to discharge them to that desired percentage?
Little off-topic opinion:
In reality, I'm not too concerned with compressing because even without it they will probably last up to 7 years and I'm sure we'll have much more efficient technology by then and they will be obsolete. But I anyway need to make an enclosure since they will stay in a camper so might as well make a compression enclosure. If they last longer it will be better for the environment as well I guess.