How are you charging None BMS 52v packs
- Thread starter bbolin
- Start date
999zip999
100 TW
More info new, used cells. High quality or flashlight batteries . 14s ?
Telemachus
10 W
Those cells are an amazing deal, I have thought of picking some up to make batteries as well. $1-1.50 each!
Did you just pull the nickel strips off, and sand down the ends a little bit?
Why wouldn't you use a BMS?
https://vruzend.com/product/52v-14s-battery-management-system-bms/
I think your only other valid option would be to separate the battery into a few smaller segments (ie: two 6s and 1 2s) and use hobby chargers, and add a low voltage alarm.
Did you just pull the nickel strips off, and sand down the ends a little bit?
Why wouldn't you use a BMS?
https://vruzend.com/product/52v-14s-battery-management-system-bms/
I think your only other valid option would be to separate the battery into a few smaller segments (ie: two 6s and 1 2s) and use hobby chargers, and add a low voltage alarm.
First time build of any battery pack. Should be receiving today so no haven't separated cells.
Got many questions. Yes pretty sure I can just bulk charge with a 52v charger. Or at least check and then bulk charge.
I've seen many Youtube videos like this regarding BMS https://www.youtube.com/watch?v=pljSZcEwc8Q
Should I get a hobby charger? icharger 208B, 1010B+ or others?
My thought was to electrically split the pack into 7s packs so it can be done with a reasonable priced balance charger. Using parallel balance.
Like I said never done this before, looking for input. This is for an ebike using Bafang BBSHD 1000W mid drive
Thanks
Got many questions. Yes pretty sure I can just bulk charge with a 52v charger. Or at least check and then bulk charge.
I've seen many Youtube videos like this regarding BMS https://www.youtube.com/watch?v=pljSZcEwc8Q
Should I get a hobby charger? icharger 208B, 1010B+ or others?
My thought was to electrically split the pack into 7s packs so it can be done with a reasonable priced balance charger. Using parallel balance.
Like I said never done this before, looking for input. This is for an ebike using Bafang BBSHD 1000W mid drive
Thanks
Telemachus
10 W
I am no expert by any means, but I don't think you can beat the convenience of a well functioning BMS. You plug the pack into an appropriate charger, and let er go. If well balanced, the charger will take each tell slightly over 4.2V, and then they will balance down to 4.2. If any cell in the pack every goes beyond a safe voltage (ie: 3.0V) then the entire pack shuts off.
The problem with a BMS is they usually don't have any logging, or anyway to know if they are actually functioning properly or not.
Hobby chargers, on the other hand, give you complete control over the charging process, and will balance charge every time. They are a little more complicated as (have to get the settings right for the charge process) and many require a separate power supply (although some have AC leads built-in). You would need something to alert you to LVC, but that is easy to come by.
I would NOT use any sore of lithium battery without either a BMS or hobby charger. IMO, bulk charging a multi-cell battery without a BMS is extremely dangerous. Yes, you will get to the right voltage, but some arrays could be at 3.9 volts and others at 4.5V! That could happen WITH a BMS as well, but is less likely to happen, since balancing should happen more regularly (in theory).
The problem with a BMS is they usually don't have any logging, or anyway to know if they are actually functioning properly or not.
Hobby chargers, on the other hand, give you complete control over the charging process, and will balance charge every time. They are a little more complicated as (have to get the settings right for the charge process) and many require a separate power supply (although some have AC leads built-in). You would need something to alert you to LVC, but that is easy to come by.
I would NOT use any sore of lithium battery without either a BMS or hobby charger. IMO, bulk charging a multi-cell battery without a BMS is extremely dangerous. Yes, you will get to the right voltage, but some arrays could be at 3.9 volts and others at 4.5V! That could happen WITH a BMS as well, but is less likely to happen, since balancing should happen more regularly (in theory).
999zip999
100 TW
Bluk charging works best with a 15ah or bigger pack. Charge to 4.125volt and discharge to 3.6v with sense wires for daily checking. Can use balance wire only charger for balancing. This is if used at your kits limits. As 30amp draw 8p or 10p better. Buy two battery lego kits.
999zip999 Your saying a lot of things I've read and seen. The intent is to usually bulk charge. Always undercharge to something like 4.125volt . Sense and balance leads are the same right? If the split battery is connected can I use the balance leeds for cell monitors?(not sure how that would work) Use balancing to verify and keep the packs in sync. The plan is to purchase 2 lego kits.
Very new at all of this. Wanted to use the lego kits to get started. Maybe then use the welding kits. Also interested in the kWeld portable being developed. Purchased DROK Numerical Control that I can connect up to some power supplies I have for bulk charging. Gives me flexibility for different size packs without spending a lot on Satiator charger.
Still unsure about the balance chargers. icharge 208B, 1010B+ or others? Not sure I understand balance chargers. Parallel boards etc... some have power connectors others don't. Do they only charge/discharge through balance leads or what. Confusing.
Thanks for input so far
Very new at all of this. Wanted to use the lego kits to get started. Maybe then use the welding kits. Also interested in the kWeld portable being developed. Purchased DROK Numerical Control that I can connect up to some power supplies I have for bulk charging. Gives me flexibility for different size packs without spending a lot on Satiator charger.
Still unsure about the balance chargers. icharge 208B, 1010B+ or others? Not sure I understand balance chargers. Parallel boards etc... some have power connectors others don't. Do they only charge/discharge through balance leads or what. Confusing.
Thanks for input so far
999zip999
100 TW
https://endless-sphere.com/forums/viewtopic.php?f=31&t=87300&hilit=Diy+lithium+battery+book. This can be helpful. 14s can be harder as most chargers 6s, 9s, 10s.
Assuming they are genuine (ya never know till you receive and characterize them), their specs are discussed in this thread (among others):Telemachus said:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=48489
Also, keep in mind that used cells (whether actually "used" or just sitting around as NOS) can vary immensely in quality and usefulness.
I would keep the existing strips, so you can use those to connect the cells together easily just by soldering to the tab sections away from the cells.
Won't work with a kit like vruzend, but would work. (has been done quite a lot of times here on ES with various toolpack batteries).
Alternately the entire packs could be used as-is, simply paralleled and seriesed as necessary to get the capacity, c-rate, and voltage needed. (as long as the voltage needed can be provided by seriesing whole packs).
then you already have the BMS internal to the pack to do balancing. Problem only arises if the BMS also has charge or discharge cutoff fets that aren't rated for the total pack voltage. But you can bypass those fi you're only using the BMS to balance, and you could run the BMS signal lines that detect HVC/LVC (if they have them) to an external signal output or cutoff device.
999zip999
100 TW
I agree with A.W. you could easily use the 2p 10s packs as 6p 10s or ? if you map out how to cut and re solder keeping the spot welder section intact.
999zip999
100 TW
Ok here's what I balance charge with una9 plus +. I also have and old threadhttps://endless-sphere.com/forums/viewtopic.php?f=14&t=86456&hilit=6s+sense+wire+charger#p1264549. And it also has a battery nanny I wish I got at the time. Now only used 3 times in 4 mo. But my Batteries are A123 20ah and 4 yrs old 1,054 cycles. Still work great. Didn't like to be drain low and lost some capacity. .5ah or is it .05ah ? I also just bluk charge as 2 packs split as 12s each. I use 16ah at most almost all the time. I did drain it once and it didn't like it . To 67v for 24s lifepo4 or 2.79 v. This is the big no no. For 18650 3.6v for good life.
999zip999
100 TW
Plus I fill a cycle analyst is a must and it's not a loaner bike as it will come back broken without a bms.
Just got around to reading the link you posted. So your running huge 24s lifep04 pack? How is lifep04 working out for you. Was looking at a lot of solar banks using them.
I don't want to parallel the ebay packs I want to build my own after I'm done tinkering. Still thinking of ichargers and split the pack for balance charge and then reconnect for use and bulk charge
I don't want to parallel the ebay packs I want to build my own after I'm done tinkering. Still thinking of ichargers and split the pack for balance charge and then reconnect for use and bulk charge
999zip999
100 TW
I love the performance. The weight and size is why I looking for a new battery that smaller and lighter. I have used this at 90amp. But 47mph on a bike is sketchy. A123 20ah ( really 18ah ) are just high quality and my last forever. Or 4.5yrs and 1,054 cycles so far. If 18650 I would need Samsung 25r.
