Li ion simultaneous charger - Page 1
Forum section: electronics / projects

author: rakeshm55
author_rank: Regular Contributor
timestamp: July 26, 2012, 01:05:49 pm
content: Hi,Is there any Li ion (3.7V , 10,000maH, battery pack) charger available in market which can charge multiple batteries simultaneously???(3.7V, 5 celll X 2200mAh = 11000mAh, battery packs. charging current of 1A or near abouts per channel.4-10 channels will be best suited.Thanks in advanceRakesh M

author: digsys
author_rank: Unknown
timestamp: July 26, 2012, 02:18:35 pm
content: Quote from: rakeshm55 on July 26, 2012, 01:05:49 pmYou're not exactly clear on what you want? Are you putting 5x cells in parallel and then up to 10 "blocks" in series? or is 5x paralleland each "block" is separate? First of all, IF all the cells are the same type and the same age, then they can be safely linked inparallel. Just MAKE SURE their individual voltages are within say 50-100mV before you do. You can put as many individual cellstogether this way. On a fresh battery design, we have up to 300-400 linked to pre-condition them.IF they are ALSO fixed in series, you can charge them up as a PACK, BUT you'll need to monitor EACK block (of 5x) to make sureit does NOT vary more than 50mV from an average !! There are plenty of BM (Battery management) modules that will do that.It's difficult to offer exact advice as we have no idea what you're trying to achieve? Final voltage? Vehicle use? etc

author: rakeshm55
author_rank: Regular Contributor
timestamp: July 26, 2012, 06:12:33 pm
content: Hi,Sorry that I was not articulate enough ,I have a system which run on a Li ion battery pack (pack is made of 5 cells connected in parallel so the battery voltage is 3.7V and capacity 11000mah (each individual cell is of 2200mah so total 11000mah). System has just one battery pack.Now My requirement is to simultaneously charge 4 to 10 system at a time. ie the charger will have 4 to 10 charging ports so that i could connect each of my system to that port.

author: digsys
author_rank: Unknown
timestamp: July 27, 2012, 10:17:38 am
content: Quote from: rakeshm55 on July 26, 2012, 06:12:33 pmHaven't come across anything off-the-shelf, and it's not a simple answer. You'll have to put something together -The first question would be .. can you do any of the work yourself, or is $$ a limitation ?OK, so you need ~5VDC at 12A per channel (IF you want to charge at 1C = 1hr rate). The charger will run in CC mode (1A) UNTILthe current drops to 1/20A (check battery chart), then it needs to switch to CV mode (4.20V - check chart)The change-over point is not critical as long as you never exceed 4.20V (4.25V for some cells), apply a trickle at some point.If you don't need more than 90% capacity, you can stop at CC end point.We may be able to find 5V/10A units, with DC control or I can come up with a design if you like? So, what path do you want to go from here?EDIT: My very first search on ebay found this -www.ebay.com/itm/universal-1A-lithium-battery-cell-liion-li-charger-board-module-In4-5-5-5V-243-/160836667133?pt=Battery_Chargers&hash=item25729cc6fdThis one is only 1A (which would take 12hrs), and you can string as many as you want together - common 0VI'm NOT suggesting this one !! quite a good catch as a very first hit ! I think this is what you're after.All PC controlled.And one at 2A -www.ebay.com/itm/DC-4-7-24V-2A-Charger-Module-For-3-6V-3-7V-500mAh-to-15000mAh-Lithium-Battery-/130737127253?pt=Battery_Chargers&hash=item1e708a3f55

author: IanB
author_rank: Super Contributor
timestamp: July 27, 2012, 02:31:49 pm
content: Why wouldn't you just use one or more of the many chargers on the market like this one?http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.htmlYou can use a balancing harness to charge several battery packs in series, or you can use a separate charger per battery pack. If you just want a charger that can do a single Li-ion at a time there are plenty of lower cost chargers that could do the job.