givre
New member
- Joined
- Dec 30, 2020
- Messages
- 12
Hello
Very new to this world, learning and reading. I hope there is some patient people around here
If you do have nice online courses/information/suggestion for someone just starting to learn about all of this, please don't hesitate to share.
Here are some questions or understanding I have about Battery Chargers and Testers
My references are more with Lithium (ion or iron)
Questions
Q1- How much voltage¤t do I need to charge a battery pack ?
I can't find the information on how I calculate this on my own.
I understand it will be very specific to the battery pack, but I would like to see how i can plan on what kind of charger I will need.
In my specific case, I would like to charge my pack using the GRID (home plugs)
Or even let if connected to the grid and charge until I get a lost of power and I am sure the charge will be the most effective.
I was thinking of something like that :
https://www.amazon.ca/-/fr/Converti...VDDE2YM09E0&psc=1&refRID=4QQ3N5EHRVDDE2YM09E0
But will see what comes out of this post ^^
Example with the packs I have :
12S8P with A123 Batteries (ANR26650M1A) like this pack https://batteryhookup.com/products/...650m1a-in-12s8p-config?variant=35854917599394
Specs of the cells :
Nominal capacity and voltage : 2.3 Ah, 3.3 V
Internal impedance (1kHz AC) : 8 mΩ typical
Internal resistance (10A, 1s DC): 10 mΩ typical
Recommended standard charge method: 3A to 3.6V CCCV, 45 min
Recommended fast charge current: 10A to 3.6V CCCV, 15 min
So the pack is a 40V and 2250A. I don't know why they say 36V and it written on the pack 40V. Mine are all around 39.x volts
Q1a- How do I know how much voltage and current I need to put into a single pack (12s8p) to charge it ( minimal /maximal /nominal)
Q1b- If I had more pack in // does this change ? For example if I add like 5 packs in //
Q1c- When charging, I don't really understand what is important : voltage or Amps . Is it better to have a 12V charger with 10A or a 30V with 10A . Maybe I just don't see how voltage and amps are flowing into each cell of a pack and how current and/or voltage will flow.
Q1d- This is more a BMS question, but, when charging a pack with a BMS, does the BMS always has to seat in between the source of energy and the pack? This is so it can cut-off when needed ?
Q1e- I see a lot of people using a BMS to balance the state of charge but I don't see a lot of monitoring/logging solution. Why that ?
Q1f- Why is it considerate "safe" to balance 1s with X cells in // without going to monitor the state of each one cells ? Or this is just the "best" of what is is possible and there is no need to monitor every single cells and wait that the 1s become poor to investigate ?
Or is there any DIY project/PCB that can handle a good unitary cell voltage and a good amount of temperature sensors ?
Understanding / Assuming
U1- Charing a battery pack with x number of cell in parallel will result as 'as full as the first cell reach the maximum voltage'
Because once the first cell in parallel will have the max voltage (and let say a BMS will cut off), that will be the end of the charging for this cell pack.
That is why a BMS can monitor as many pack in // because he will only see series if all the 12s have their own connexion (all the 1s together, all the 2s together and so on)
U2- if I have a 3000w inverter and that I use at the maximum of 3000w continue on the 36v if I want to know the discharge current that will be passing in the BMS i can just do ( 3000w/36v = 83 Amps)
Thanks a lot for you help and valuable knowledge
Ben
Very new to this world, learning and reading. I hope there is some patient people around here
If you do have nice online courses/information/suggestion for someone just starting to learn about all of this, please don't hesitate to share.
Here are some questions or understanding I have about Battery Chargers and Testers
My references are more with Lithium (ion or iron)
Questions
Q1- How much voltage¤t do I need to charge a battery pack ?
I can't find the information on how I calculate this on my own.
I understand it will be very specific to the battery pack, but I would like to see how i can plan on what kind of charger I will need.
In my specific case, I would like to charge my pack using the GRID (home plugs)
Or even let if connected to the grid and charge until I get a lost of power and I am sure the charge will be the most effective.
I was thinking of something like that :
https://www.amazon.ca/-/fr/Converti...VDDE2YM09E0&psc=1&refRID=4QQ3N5EHRVDDE2YM09E0
But will see what comes out of this post ^^
Example with the packs I have :
12S8P with A123 Batteries (ANR26650M1A) like this pack https://batteryhookup.com/products/...650m1a-in-12s8p-config?variant=35854917599394
Specs of the cells :
Nominal capacity and voltage : 2.3 Ah, 3.3 V
Internal impedance (1kHz AC) : 8 mΩ typical
Internal resistance (10A, 1s DC): 10 mΩ typical
Recommended standard charge method: 3A to 3.6V CCCV, 45 min
Recommended fast charge current: 10A to 3.6V CCCV, 15 min
So the pack is a 40V and 2250A. I don't know why they say 36V and it written on the pack 40V. Mine are all around 39.x volts
Q1a- How do I know how much voltage and current I need to put into a single pack (12s8p) to charge it ( minimal /maximal /nominal)
Q1b- If I had more pack in // does this change ? For example if I add like 5 packs in //
Q1c- When charging, I don't really understand what is important : voltage or Amps . Is it better to have a 12V charger with 10A or a 30V with 10A . Maybe I just don't see how voltage and amps are flowing into each cell of a pack and how current and/or voltage will flow.
Q1d- This is more a BMS question, but, when charging a pack with a BMS, does the BMS always has to seat in between the source of energy and the pack? This is so it can cut-off when needed ?
Q1e- I see a lot of people using a BMS to balance the state of charge but I don't see a lot of monitoring/logging solution. Why that ?
Q1f- Why is it considerate "safe" to balance 1s with X cells in // without going to monitor the state of each one cells ? Or this is just the "best" of what is is possible and there is no need to monitor every single cells and wait that the 1s become poor to investigate ?
Or is there any DIY project/PCB that can handle a good unitary cell voltage and a good amount of temperature sensors ?
Understanding / Assuming
U1- Charing a battery pack with x number of cell in parallel will result as 'as full as the first cell reach the maximum voltage'
Because once the first cell in parallel will have the max voltage (and let say a BMS will cut off), that will be the end of the charging for this cell pack.
That is why a BMS can monitor as many pack in // because he will only see series if all the 12s have their own connexion (all the 1s together, all the 2s together and so on)
U2- if I have a 3000w inverter and that I use at the maximum of 3000w continue on the 36v if I want to know the discharge current that will be passing in the BMS i can just do ( 3000w/36v = 83 Amps)
Thanks a lot for you help and valuable knowledge
Ben