solarbbq2003
10 kW
- Joined
- Apr 7, 2007
- Messages
- 500
Just been thinking about making up some led monitors to put on cobalt oxide cells, has been suggested that a simple way would be use zener diodes so that leds switch on/off at given voltages, or a comparator circuit ( more complex).
I think it would be very useful to have an overvoltage (when charging) and undervoltage indicator on each cell ( though alot of work to set up), would certainly make for a safe system and easy diagnosis of a faulty cell.
I'm guessing a bit but overvolt led lights at 5v? and undervolt an led lights at 2.4v?? only for cobalt oxide i'm thinking here ( same could apply to iron phosphate but different voltages).
anyway would anyone have any clue on how to use zener diodes to make an led turn on when cell goes down to 2.4v or if it goes over 5v when charging. I would imagine two leds on each cell would do the job.
recently got a stack of old cyclone lithiums , the cells are fine but the bms boards are very bad, so intending on puting some better bms boards on them and puting to good use. I've got quite a few cells here, which are 5ahr in metal cases, if anyone is looking for cells ( cobalt oxide give me a yell) the person who had them is looking to get a bit of money back on a bad investment in these batteries, he would be happy with about $220aud per 24v 15ahr pack, but the bms boards are not good, very dodgey.
Cells seem fine, charge up fine, some seem to have undergone some gasing as the cases have buldged out slightly, but dont seem to have lost capacity at all.
Just a note on the lithiums I was selling on my website, you guys were right , the damn company was selling me cobalt cells and telling me they were iron phosphate..........have been sourcing from different companies, there is an awful lot of new companies springing up making iron phosphates in china, prices seem to range from $1.60usd/ahr to over $2usd/ahr.
I think it would be very useful to have an overvoltage (when charging) and undervoltage indicator on each cell ( though alot of work to set up), would certainly make for a safe system and easy diagnosis of a faulty cell.
I'm guessing a bit but overvolt led lights at 5v? and undervolt an led lights at 2.4v?? only for cobalt oxide i'm thinking here ( same could apply to iron phosphate but different voltages).
anyway would anyone have any clue on how to use zener diodes to make an led turn on when cell goes down to 2.4v or if it goes over 5v when charging. I would imagine two leds on each cell would do the job.
recently got a stack of old cyclone lithiums , the cells are fine but the bms boards are very bad, so intending on puting some better bms boards on them and puting to good use. I've got quite a few cells here, which are 5ahr in metal cases, if anyone is looking for cells ( cobalt oxide give me a yell) the person who had them is looking to get a bit of money back on a bad investment in these batteries, he would be happy with about $220aud per 24v 15ahr pack, but the bms boards are not good, very dodgey.
Cells seem fine, charge up fine, some seem to have undergone some gasing as the cases have buldged out slightly, but dont seem to have lost capacity at all.
Just a note on the lithiums I was selling on my website, you guys were right , the damn company was selling me cobalt cells and telling me they were iron phosphate..........have been sourcing from different companies, there is an awful lot of new companies springing up making iron phosphates in china, prices seem to range from $1.60usd/ahr to over $2usd/ahr.