Hi all,
My distaste for BMSes has ended. Looking for an affordable one (from China, not much of a choice). Need advice. 1st timer...help!!
I've newly acquired 36 x 74Ah LFP cells for a 32s1p arrangement. 4 spares. E-motorbike DIY. Battery + BMS selection stage.
All cells are in the mid-SOC range now (3.290 to 3.291V) about 30-40%. They cost USD6k....darn.
- The BMS needs to be rather flat (20mm height max), not the layered high types. Surface area can be up to 250 x 250.
- The link below shows a 2.50 - 3.65V BMS that's about $200 USD. But I'm willing to fork out another $200 USD for customization costs.
http://item.taobao.com/item.htm?spm=2013.1.20141001.2.OsiSSm&id=42190888184&scm=1007.10115.2077.i26262124428&pvid=de7844bf-fb6d-4226-b425-859a4defe3ea
****************************************************
Specifications are translated:
● 32S BMS, 150A
● L170 W140 H10 (White socket height 13mm) (My max is 20mm)
● 0.35kg
● Overcharge Protection: 3.65V (i.e., Either individually over 3.65v or combined over 116.8V, the charger switches to balancing mode).
● Over-discharge protection: 2.5V (i.e., LVC at 80V).
● Continuous current: 150A (suitable for 2kW-4kW motor/load).
● Overcurrent protection: 250A.
● Maximum Charge Current: 20A.
● Temperature Protection: 75 degrees (optional).
● Balancing Current: 100mA.
● Power Consumption: approx 50uA.
● Resistance: less than 8mΩ.
● MOSFETS: 200v To-247 (I think it's 4668 but the whole BMS is 2nd-hand).
● Charging and discharge ports are separated. For current past 60A, separated port types are better suited than non-separated-port configs.
*******************************
Q: If I've to stick with this vendor, and can discuss w him via phone, what specific components shall I tell him to REPLACE/CUSTOMIZE/CALIBRATE before purchase...?
My new batts are shown below. Pics 2 - 6 prove that a BMS is necessary. They were only at about 30% SOC. All 32 had been parallel balanced and all read 3.298V on the multi-meter. The mini green voltmeters are + 0.03 to + 0.04V from the multi-meter. So 3.34V is near 3.30V. The bulk-charger is 113V, 6A.
I wouldn't like an excessively crappy BMS ruining the pricey CALB batts...yet neither a bulky $1500 Canbus BMS, meant for cars.
Thanks
My distaste for BMSes has ended. Looking for an affordable one (from China, not much of a choice). Need advice. 1st timer...help!!
I've newly acquired 36 x 74Ah LFP cells for a 32s1p arrangement. 4 spares. E-motorbike DIY. Battery + BMS selection stage.
All cells are in the mid-SOC range now (3.290 to 3.291V) about 30-40%. They cost USD6k....darn.
- The BMS needs to be rather flat (20mm height max), not the layered high types. Surface area can be up to 250 x 250.
- The link below shows a 2.50 - 3.65V BMS that's about $200 USD. But I'm willing to fork out another $200 USD for customization costs.
http://item.taobao.com/item.htm?spm=2013.1.20141001.2.OsiSSm&id=42190888184&scm=1007.10115.2077.i26262124428&pvid=de7844bf-fb6d-4226-b425-859a4defe3ea
****************************************************
Specifications are translated:
● 32S BMS, 150A
● L170 W140 H10 (White socket height 13mm) (My max is 20mm)
● 0.35kg
● Overcharge Protection: 3.65V (i.e., Either individually over 3.65v or combined over 116.8V, the charger switches to balancing mode).
● Over-discharge protection: 2.5V (i.e., LVC at 80V).
● Continuous current: 150A (suitable for 2kW-4kW motor/load).
● Overcurrent protection: 250A.
● Maximum Charge Current: 20A.
● Temperature Protection: 75 degrees (optional).
● Balancing Current: 100mA.
● Power Consumption: approx 50uA.
● Resistance: less than 8mΩ.
● MOSFETS: 200v To-247 (I think it's 4668 but the whole BMS is 2nd-hand).
● Charging and discharge ports are separated. For current past 60A, separated port types are better suited than non-separated-port configs.
*******************************
Q: If I've to stick with this vendor, and can discuss w him via phone, what specific components shall I tell him to REPLACE/CUSTOMIZE/CALIBRATE before purchase...?
My new batts are shown below. Pics 2 - 6 prove that a BMS is necessary. They were only at about 30% SOC. All 32 had been parallel balanced and all read 3.298V on the multi-meter. The mini green voltmeters are + 0.03 to + 0.04V from the multi-meter. So 3.34V is near 3.30V. The bulk-charger is 113V, 6A.
I wouldn't like an excessively crappy BMS ruining the pricey CALB batts...yet neither a bulky $1500 Canbus BMS, meant for cars.
Thanks
