Jack.Straw
Member level 2
Hello. I'm building a 12v bluetooth speaker and am trying to design the battery and charging system. I'm thinking about using 3 of the Panosonic NCR18650B in series to start, and then perhaps upgrade to another 3 pack in parallel later if the battery life isn't good enough. This is my first experience building something with Lithium batteries and it's a bit intimidating. I've done quite a bit of reading, but i wanted to come here and ask a few questions in hopes of getting this right the 1st try.
The BMS i've chosen (linked here) shows "charge/discharge" on one of the images for the P+ and P- terminals. I'm hoping this means that I can connect my incoming power AND my load (12v amp & bluetooth module) to those terminals and it will allow me to use the amp while charging. In the description it says "Charge with 12.6-13.0V Power supply (not included)." With that in mind, here are my questions:
1) I was working under the assumption that i would need a battery charger or charging circuit before the BMS, but the description makes it sound like i can just put a power supply directly to the BMS. Would one of the 12.6v li-ion plug-in style chargers (like this one) be ok to use with this BMS? Would a charger like that cause interference noise in the speaker?
2) When connecting the power and load to the BMS, do i need any kind of diode in line with the load?
3) I was planning to get the protected versions of these batteries, but is that necessary if i use the BMS and charger that also offers protection? If I was to use the protected batteries, does that eliminate the need for the BMS?
I have built NiMH chargers using the Maxim ICs in the past that allow for charging and load as the same time without any interference, and I know that option is available for Li-Ion as well. However, i would REALLY like to avoid making my own charger if possible.
Thanks for any advice you can offer!
The BMS i've chosen (linked here) shows "charge/discharge" on one of the images for the P+ and P- terminals. I'm hoping this means that I can connect my incoming power AND my load (12v amp & bluetooth module) to those terminals and it will allow me to use the amp while charging. In the description it says "Charge with 12.6-13.0V Power supply (not included)." With that in mind, here are my questions:
1) I was working under the assumption that i would need a battery charger or charging circuit before the BMS, but the description makes it sound like i can just put a power supply directly to the BMS. Would one of the 12.6v li-ion plug-in style chargers (like this one) be ok to use with this BMS? Would a charger like that cause interference noise in the speaker?
2) When connecting the power and load to the BMS, do i need any kind of diode in line with the load?
3) I was planning to get the protected versions of these batteries, but is that necessary if i use the BMS and charger that also offers protection? If I was to use the protected batteries, does that eliminate the need for the BMS?
I have built NiMH chargers using the Maxim ICs in the past that allow for charging and load as the same time without any interference, and I know that option is available for Li-Ion as well. However, i would REALLY like to avoid making my own charger if possible.
Thanks for any advice you can offer!