chvidgov.bc.ca
10 kW
My headway build begins...planning to build a 48V 10Ahr unit. 31802S cells (16S).
--------EDIT - Retrospective/conclusion/bottom line-----------
At first, I had some issues with the first Signalab 2.5 BMS I installed, blew it up, but the replacement Signalab 2.5 is now installed. It works ok, but some manual balancing may be required over time, sporadically, as it doesn't equalize the cells particularly well after all the LED lights come on, around 57.6 volts out of 58.4 that the charger is set to...my whole experience with the Signalab is outlined here, with much help from DNMUN, the saga ends happily. I learned a lot about balancing the Headways on the Signalab and constructing the packs. The bottom line is that..."After all the LEDs are lit up, and the charger is quiescent but still connected, if you drain one cell with a resister, the overall pack voltage will be maintained at close to 58.4, so energy is going into the other cells, which is improving the balance beyond the "All LEDs are on" point - that point doesn't truly reflect perfect balance. Further manual balancing beyond the "all LEDs are on" point is necessary, now and then. Which isn't difficult.
------------------------------------------------
...the REST of the story........
Ordered from BMSBattery.com. All cells arrived in Victoria, British Columbia in about 6 days. With interconnects and orange plastic blocks. Planning on using Signalab 2.5. All cells were 3.32 on arrival. No complaints on service.
Soldered sense wires to interconnects (not on battery at time) by drilling tiny hole in interconnect and putting sense wires through them, and soldering. Taped over centres of buss interconnects and sense wires to protect solder junction from flex and shorting from screw to can.
Assembled pack in orange blocks. Snug fit, no removal of outside blue material necessary. No cracking of blocks. No condoms.
Attached buss interconnects/sense wires, in correct order, by drilling small holes in middle of interconnects, and soldering sense wires into holes. Total voltage of pack 53.2. All sense wires in order, and checked for incremental voltages at the white plug (all increased by 3.2 volts, up toward 53.2). Definitely in the right order..
Attached Signalab 2.5 bms as per Ping diagram. Probed white plastic connector at each sense wire. Each one went up by 3.2 volts as required, to total voltage of 53.2-3, on last wire, so all sense wires operating correctly.
Started charging, with Ping charger (61volts according to multimeter). I should have used a cooler charger, maybe 59.2 volts - even though I thought I should do this - I was too eager, and I thought the cells were balanced already (my bad).
9 LEDS go on, after a bunch of on/off cycles of the charger. Everything looks ok, except pack voltage is now over 60...
Checked all cell voltages as pack voltage - WTF - one cell is at 4.2!
I hear a loudish pop. Don't know whether it was the BMS dying, or a cell going down. 9 Leds on BMS still on, but no output. BMS LVC? One cell is down (zero volts). Others range from 3.3 to 3.75 (also too high).
My original plan was to charge with one single cell charger, to 3.65, with all cells connected in parallel, then connect the bms, too impatient.
So, I am ordering a replacement cell, and I'm going to try the "new" bmsbattery bms. http://www.bmsbattery.com/5-bmspcm , after balancing at 3.65 all the cells.
--------------
I drained all of the high cells down to 3.65 for storage over the next week.
I will single cell charge all of them in parallel to 3.65 to bring up the low cells, and get closer to balance...
I will then find a charger that puts out only about 3.7 per cell (59.2), and hook that up.
I will try the Signalab 1.0 I have, or maybe the bmsbattery "new" bms http://www.bmsbattery.com/5-bmspcm (which is what BMSBattery provides in pre-assembled pack).
Hopefully I haven't damaged too much the other high cells which were over 3.7
-------------
Question - did I really kill the BMS? If the LEDs are still on?
Why didn't the BMS prevent HV condition on the high cell? I thought it would cut in at 3.9?
Maybe the Signalab V1 could "bleed" more current preventing HV state on high cell? Compared to the v2.5 version.
How to adjust down the voltage of the el-cheapo Ping 2 amp charger. 61.4 is awefully high?
What BMS should I use, and where can I get one. I'm not competent to build a GoodrumFechter type.
--------------
HELP?/Comments welcome. I'd prefer plug and play as I have a low attention span when it comes to these batteries...
--------EDIT - Retrospective/conclusion/bottom line-----------
At first, I had some issues with the first Signalab 2.5 BMS I installed, blew it up, but the replacement Signalab 2.5 is now installed. It works ok, but some manual balancing may be required over time, sporadically, as it doesn't equalize the cells particularly well after all the LED lights come on, around 57.6 volts out of 58.4 that the charger is set to...my whole experience with the Signalab is outlined here, with much help from DNMUN, the saga ends happily. I learned a lot about balancing the Headways on the Signalab and constructing the packs. The bottom line is that..."After all the LEDs are lit up, and the charger is quiescent but still connected, if you drain one cell with a resister, the overall pack voltage will be maintained at close to 58.4, so energy is going into the other cells, which is improving the balance beyond the "All LEDs are on" point - that point doesn't truly reflect perfect balance. Further manual balancing beyond the "all LEDs are on" point is necessary, now and then. Which isn't difficult.
------------------------------------------------
...the REST of the story........
Ordered from BMSBattery.com. All cells arrived in Victoria, British Columbia in about 6 days. With interconnects and orange plastic blocks. Planning on using Signalab 2.5. All cells were 3.32 on arrival. No complaints on service.
Soldered sense wires to interconnects (not on battery at time) by drilling tiny hole in interconnect and putting sense wires through them, and soldering. Taped over centres of buss interconnects and sense wires to protect solder junction from flex and shorting from screw to can.
Assembled pack in orange blocks. Snug fit, no removal of outside blue material necessary. No cracking of blocks. No condoms.
Attached buss interconnects/sense wires, in correct order, by drilling small holes in middle of interconnects, and soldering sense wires into holes. Total voltage of pack 53.2. All sense wires in order, and checked for incremental voltages at the white plug (all increased by 3.2 volts, up toward 53.2). Definitely in the right order..
Attached Signalab 2.5 bms as per Ping diagram. Probed white plastic connector at each sense wire. Each one went up by 3.2 volts as required, to total voltage of 53.2-3, on last wire, so all sense wires operating correctly.
Started charging, with Ping charger (61volts according to multimeter). I should have used a cooler charger, maybe 59.2 volts - even though I thought I should do this - I was too eager, and I thought the cells were balanced already (my bad).
9 LEDS go on, after a bunch of on/off cycles of the charger. Everything looks ok, except pack voltage is now over 60...
Checked all cell voltages as pack voltage - WTF - one cell is at 4.2!
I hear a loudish pop. Don't know whether it was the BMS dying, or a cell going down. 9 Leds on BMS still on, but no output. BMS LVC? One cell is down (zero volts). Others range from 3.3 to 3.75 (also too high).
My original plan was to charge with one single cell charger, to 3.65, with all cells connected in parallel, then connect the bms, too impatient.
So, I am ordering a replacement cell, and I'm going to try the "new" bmsbattery bms. http://www.bmsbattery.com/5-bmspcm , after balancing at 3.65 all the cells.
--------------
I drained all of the high cells down to 3.65 for storage over the next week.
I will single cell charge all of them in parallel to 3.65 to bring up the low cells, and get closer to balance...
I will then find a charger that puts out only about 3.7 per cell (59.2), and hook that up.
I will try the Signalab 1.0 I have, or maybe the bmsbattery "new" bms http://www.bmsbattery.com/5-bmspcm (which is what BMSBattery provides in pre-assembled pack).
Hopefully I haven't damaged too much the other high cells which were over 3.7
-------------
Question - did I really kill the BMS? If the LEDs are still on?
Why didn't the BMS prevent HV condition on the high cell? I thought it would cut in at 3.9?
Maybe the Signalab V1 could "bleed" more current preventing HV state on high cell? Compared to the v2.5 version.
How to adjust down the voltage of the el-cheapo Ping 2 amp charger. 61.4 is awefully high?
What BMS should I use, and where can I get one. I'm not competent to build a GoodrumFechter type.
--------------
HELP?/Comments welcome. I'd prefer plug and play as I have a low attention span when it comes to these batteries...