All Questions
17 questions
1
vote
2
answers
99
views
Confused about this BMS
I recently got a BMS model "bw-6022-5s" and planned to use it with my 4S5P (21V) battery pack. However, since this BMS looked different from the ones I'm used to, I did some research and ...
- 41
0
votes
2
answers
69
views
18650 cell will use ______ amps every _____mins?
I am looking at how to utilise the BQ77915 Ultra-Low Power Primary Protector with Autonomous Cell Balancing by TI, using eight 18650 cells, each with a BQ77915 IC allowing 3 series - 5 series cells.
...
- 69
1
vote
1
answer
230
views
Reverse polarity protection for parallel connection of 18650 batteries
I want to use two Li-Ion 18650 batteries in the device. The batteries need to be connected in parallel and they can be removed from the device (holder).
The device itself is protected from incorrect ...
- 11
1
vote
1
answer
655
views
How to get a stable 3.3V/2A output out of a single cell (18650 Li-ion) battery?
In my tiny quadcopter, I need to power a long range wifi card which take 3.3V/2A max as input. The quad runs off a single high current 18650 Li-ion battery.
Are there any chips or modules that will ...
- 337
0
votes
1
answer
601
views
Is my 4s2p pack connections correct?
I'm planning to build my 4S2P battery pack using 18650 lithium-ion battery cells. I need to make sure my connections and my battery pack is correct and safe before I make the connections. Here's the ...
- 3
0
votes
0
answers
22
views
How to monitor capacity of 18V Li-Ion battery pack? [duplicate]
I have been learning more about how battery packs work and are made. I have been playing around with this one: https://www.batteryspace.com/li-ion-18650-battery-18v-2900-mah-52wh-7a-rate-5s-s-...
- 183
1
vote
0
answers
125
views
BMS abnormal behavior
I would like to power the lighting system of a small cabin using 3 DeWalt 18 V, 5 Ah battery packs. The system consists of six 10 W bulbs each (12/24 V) and a 20 W, 12 V spotlight.
DeWalt battery ...
0
votes
1
answer
111
views
Isolated two battery load/charging system (parallel 18650)
I am working on a project and wanted it to be very robust and user-friendly. To power said device, I had planned on using two 18650 in series (li-ion), like everyone else. The problem I had was that ...
3
votes
1
answer
130
views
Protecting parallel 18650 cells
My son is doing an Eagle project where he is creating a solar charged LED light set up using two 18650 cells in parallel. We are working to ensure they are safely protected. From the research we have ...
0
votes
1
answer
86
views
When I test a 18650 Li-ion cell, why do I get two different values of capacity for charging and discharging?
I'm trying to test the capacity of 18650 cells. I don't know which numbers are important. I get different results on the same cells from discharge and the charge.
For example on same 18650 cell:
(...
- 9
2
votes
5
answers
1k
views
Is this a good way to make 2S 18650 battery cell while parallel charging?
I want to make a battery pack with 7.4 volt output and I want to charge them with 1A each so I connect them parallelly and input them with 5A 6A DC adapter. (No charging and using at the same time) Is ...
- 21
1
vote
0
answers
48
views
Voltage leak when muxing Li-ion cells for voltage measurements?
A disclaimer before I dive in, I am not working with a battery pack. Anytime I refer to Li-Ion cells or 18650s, I am trying to handle each cell as an individual. I am actually avoiding building a ...
- 11
1
vote
2
answers
726
views
Are loose 18650 batteries safe? [closed]
Are loose 18650 batteries safe?
In some countries they are about the most common type of battery on the market.
- 165
1
vote
1
answer
160
views
What is the name of this connector and where can I find it?
Any ideas on where I can locate this connector? It is from a bike light and connected directly to 18650 battery. 3mm x 2mm with 4 holes, but 2 wires from the battery. On the motherboard the connector ...
- 11
1
vote
0
answers
269
views
BMS shows wrong voltage, changes to 0 V under load
I made a 24 V, 4400 mAh lithium-ion battery using 18650 cells connected in a 7S 2P configuration.
When I check the pack output voltage without the BMS it's around 21 V (very low, undercharged). When I ...
0
votes
1
answer
576
views
Can I mix three 18650s with different brands?
I have three 18650 batteries with different brands, but the same voltage and capacity. Can I mix them using a 3s BMS with balancer without a risk?
0
votes
1
answer
937
views
Typical thermistor spec for li-ion pack?
I'm trying to save an inherited Stiga lawnmower with a battery pack that I thought was dead. It's a 20 cell 18650 pack at 36V. When newly charged, the running time is just a few minutes before the ...
- 415