hybridfree/eevblog-posts huggingface dataset:
Batt Charger controller downstream of regulator issues - Page 1
Forum section: electronics / projects

author: rfleming
author_rank: Regular Contributor
timestamp: March 03, 2022, 06:36:38 am
content: Hi all,I have inherited a PCB Batt charging circuit to diagnose and have been overwhelmed with its datasheet and its expansive list of 100s of registers controllable over I2C. I am relatively novice with charging circuits, so I reaching out hoping someone can assist.I have a Richtek RT9466 and have found that without any controller, its default position is if I try to immediately draw 400mA on power-up from a resistive load without a battery, it fails to bring the line into regulation and will output anywhere from 0 - 1V.While this wont be the case in practical application, what WILL happen is the device gets left powered on for an extended period, effectively my battery hits 0V (well, its ~2.7V safety minimum) and will stop providing power. The charging IC won't be able to output the target voltage without the battery connected.From this case I dont see how anyone else with this controller could get it working immediately unless 1 of 2 things.1. There is an issue with our layout/schematic2. The Controller IC that can interact with the RT9466 over I2C can configure one of the registers to fix the above state.This brings an interesting though though for #2. Currently I am using my main micro that is powered directly from this IC's SYS pin (pins 15/16). Should I the controller for the IC be connected via these IOs? or should it instead be connected to a different set that could power a controller directly? Currently I run into the conundrum that I cannot control the charger IC if my controller down stream doesn't get power. And if the default state of the charger if the battery was removed/dead when the charger is finally applied, is to output 0V, I can't use this as a solution.A few Notes:- I am using my bench PSU as the charge source atm, set at 5V.- When the battery is not installed and is outputting 0-1V as above through the charging IC. The battery terminal measures ~2V.- If I start the IC with no load for a couple seconds, then apply the load it appears to go into regulation correctly and maintain it when varying the load.- If I connect the battery, then apply supply the charger with no load, it hits 1.5A for ~1s then stops chargingAttached is the basic schematic of the battery charger. I can confirm I2C does work when the battery is connected etc.
Batteri and current - Page 1
Forum section: electronics / projects

author: jarleiceman
author_rank: Contributor
timestamp: December 21, 2013, 11:43:29 pm
content: View ProfileEmailPersonal Message (Online)Problems with battery current« on: Today at 06:42:52 AM »QuoteModifyRemoveHello O0I have a headphone With an 3.6v AAA 500mA batery li-ion, reachargebal. ,and I want to put in a plug so I can recharge it. but if I use a USB Connection (5v) li-ion, what size shal my resistan has....I dont know what te battery can take..3.6v---4,2v...I dont know...and which plug shal I use on the earphhones ( BOSE SoundComford 15) I know U=R x I but what current shal I choose,what current does the battery take....jarleiceman

author: IanB
author_rank: Super Contributor
timestamp: December 21, 2013, 11:49:50 pm
content: The Bose QuietComfort 15 headphones use a single AAA 1.5 V battery.If you don't want to use a disposable alkaline battery you can probably use a rechargeable AAA NiMH battery. I would suggest an Eneloop as these are very good quality and high performing batteries.To recharge it you will need an NiMH charger that can charge a single battery at a time.

author: jarleiceman
author_rank: Contributor
timestamp: December 22, 2013, 12:49:58 am
content: I have modified the amplifier in the headset, snd they need 3,4-3,6 v,,,much greater sound !!!!

author: Nerull
author_rank: Frequent Contributor
timestamp: December 22, 2013, 01:46:20 am
content: You cannot charge a 3.6V lithium battery from a 5V supply, no matter what resistors you use. Itwillcatch fire.Properly charging lithium batteries properly requires an active monitoring circuit that can monitor the battery, limit charging current, and stop charging when the battery is fully charged. It must never go above 4.2V. Simply float charging li-ions is not a good idea.Something like this might work, you can put it in a small project box with a cord that plugs into the headphones:https://www.sparkfun.com/products/10217If your skills are up to it, you could also build your own circuit using the same/similar charging IC and integrate it into the headphones.
Batteries in series - Page 1
Forum section: electronics / projects

author: fredjh
author_rank: Newbie
timestamp: November 02, 2022, 01:19:23 pm
content: Hi,I am making a battery pack using few stacks of seried battery tools and I want the load to use all batteries. I do not want to parallel the batteries as the may have various charges (voltages). Obviously a schottcky diode like mbr3045pt can do what I want but it will waste about 6 watts at 20A forward bias. Of course one can use Mosfets as blocking diodes like the link below. But, problem arises once there is power present after the mosfet (coming from another battery pack) and it will keep the Mosfet.https://www.rs20.net/w/2013/02/using-mosfets-as-blocking-diodes-reverse-polarity-protection/Any magical simple solutions you may think of? Thanks!P.S. New to the forum but a long time watcher and Pateron to Dave. Great work.

author: Dave
author_rank: Super Contributor
timestamp: November 02, 2022, 01:48:14 pm
content: An ideal diode controller IC is what you're looking for.LM5050-2, for example.Welcome to the forum!

author: fredjh
author_rank: Newbie
timestamp: November 02, 2022, 02:02:04 pm
content: Wow! That was fast and to the point. Thanks Dave. Now I have to find one that is a bit easier to solder. This will be more like a deadbug soldering that an actual board!
Batteroo ReBoost, batterizer 2 - let the debunking begin - Page 1
Forum section: electronics / projects

author: Scottjd
author_rank: Frequent Contributor
timestamp: July 30, 2017, 02:44:26 pm
content: Just see this thread, tHis seems to be continued on the other thread.No need to duplicate things.https://www.eevblog.com/forum/blog/eevblog-751-how-to-debunk-a-product-(the-batteriser)/msg1276490/#msg1276490

author: usagi
author_rank: Frequent Contributor
timestamp: July 31, 2017, 08:58:20 am
content: list of fake news producers:

author: SaabFAN
author_rank: Frequent Contributor
timestamp: August 01, 2017, 11:53:13 pm
content: These things would help in my old PM3320A Oscilloscope.With alkaline batteries, the time doesn't lag behind that much as with NiMH-Accumulators. But I cannot use Alkalines, because the scope actually starts charging the batteries once turned on (had Alkalines in there and it took 2 days of using the scope to make them leak all over the place).If these Reboost-Thingies are able to let charge-current through, I might actually buy them for my scope. Just because the problem with the timing annoys me.Or I'll build some kind of LiPo-Solution like I did for my Logic Analyzer

author: Scottjd
author_rank: Frequent Contributor
timestamp: August 08, 2017, 11:58:34 pm
content: Instead if this being a new thread as a different product it seems to be continuing under the old original baterizzer/batteroo thread. So to prevent duplicate threads and make searching easier I've decided to just refer everyone to this thread.https://www.eevblog.com/forum/blog/eevblog-751-how-to-debunk-a-product-(the-batteriser)/msg1276490/#msg1276490
Battery-backed power fail-over - Page 1
Forum section: electronics / projects

author: magiccow
author_rank: Contributor
timestamp: October 07, 2013, 03:37:54 pm
content: I've been looking for a circuit for fail-over to battery on power outage. The LD1117 datasheet has quite a nice thing (page 16) that uses two LD1117s with outputs directly connected:https://www.sparkfun.com/datasheets/Components/LD1117V33.pdfThey have a battery charging circuit on the left. I'm guessing this means a 6v lead acid battery? I'd quite like to put some NiMH AA cells in there. Does anyone have an idea how to put the right charging circuit in there?

author: alank2
author_rank: Super Contributor
timestamp: October 07, 2013, 03:56:56 pm
content: What I've done for a battery backup is use a couple of 1N5817 Schottky diodes to join two voltage sources together so they can't back feed each other. Whichever voltage is higher by around 0.4V will provide 100% of the load. I then feed that into a SMPS and output 5V from that. If either voltage source drops out, the other immediately takes over.

author: MinK
author_rank: Contributor
timestamp: October 07, 2013, 03:57:54 pm
content: Check out this circuit for emergency light, i guess that solution might be good to you.http://www.circuitstoday.com/automatic-led-emergency-light-modified-versionTo turn battery power on PNP transistor T2.
Battery backup circuit - Page 1
Forum section: electronics / projects

author: nuclearcat
author_rank: Unknown
timestamp: July 02, 2020, 10:38:29 am
content: I am thinking to do battery backup and "debounce" circuit based on "reset ic" like mentioned inhttps://www.maximintegrated.com/en/design/technical-documents/app-notes/1/1136.htmlBut as supplier(LCSC) dont have them, i am considering to use TPS3823 (https://datasheet.lcsc.com/szlcsc/1810181824_Texas-Instruments-TPS3823-33DBVR_C7719.pdf)but not really sure this circuit going to work:Do you think it will work?
Battery Balancing and Hotswapping - Page 1
Forum section: electronics / projects

author: camdenmil
author_rank: Newbie
timestamp: February 23, 2015, 05:49:05 pm
content: Hi everyone,I am working on a power systems for a new robot. The chosen power system consists of 2 battery packs with a 26V nominal voltage. Each battery can supply a maximum of 10A and the robot draws around 16A under full load. The batteries are not going to be charged in-system but we would like to implement hot-swapping of the battery packs (the robot will not be drawing near 10A while the batteries are being hot swapped). The batteries are at 29.4V fully charged and at 17V when over-discharged.The previous robot (designed and built years ago before any of the current team members were involved) had 6 smaller battery packs and used an LTC4412HV coupled with a power MOSFET for each battery to create an 'ideal diode' to implement diode OR-ing of all the batteries onto a single bus. Is this technique a good practice for power applications and does it effectively share the load of the batteries? If not, how can I approach balancing the batteries onto a single bus without significant losses in power conversion? Also, how can I make the system safe for hotswapping?

author: Rerouter
author_rank: Super Contributor
timestamp: February 23, 2015, 07:29:31 pm
content: hot swap controllers would only work out if the load was less than what a single battery was rated for, (it only connects the battery with the highest voltage)for you... i'm guessing that 26V you dont use directly? if so you could likely parellel 2 buck/boost/sepic regulators to give you the output you seek independent of the voltage of the batteries, (look at multiphase regulators)
Battery capacity question, Iavg vs Irms as they relate to PWM - Page 1
Forum section: electronics / projects

author: turbo!
author_rank: Regular Contributor
timestamp: December 07, 2014, 11:06:08 pm
content: Many devices are using PWM hence the question.Given a battery with capacity of 20Ah, the simple view of this is the product of amperes x hours. So2A x 10 hrs and 20A x 1 both give the same answer.Lead acid batteries are rated at C/20 which means that a 20Ahr battery provides 1A for 20 hours.Realistically, they're often used at C/0.5 to C/1 rate and I believe the Ah capacity at these realistic discharge rate is only about half the rated Ah.When a battery is loaded with a PWM load, do you use the RMS amps and relate it to the losses in battery due to its internal resistance or is it more about pacing out and giving time for chemical reactions to catch up and use Iavg?Example parameters:Battery is rated 5Ah400Hz PWM, on-state current = 2AHypothetical internal series resistance = 1 ohmpercent cycle = 25%If this continues for an hour, the cumulative Ah is 2 x 0.25 = 0.5AhHowever, the loss in the resistance is actually 2A x 2A x 1 ohm= 4W and 4w x 25% = 1W.A steady 0.5A would be 0.5x0.5x1 = 0.25W.The Iavg is the same in either cases, but the Irms of PWM is doubled.Would you figure the available capacity of this battery based on C/10 (0.5A) using Iavg of 0.5A or would you use C/5(1A) using Irms of 1A?

author: Mad ID
author_rank: Regular Contributor
timestamp: December 07, 2014, 11:31:34 pm
content: Have a look at this:http://en.wikipedia.org/wiki/Peukert%27s_law

author: turbo!
author_rank: Regular Contributor
timestamp: December 11, 2014, 08:16:55 am
content: Quote from: Mad ID on December 07, 2014, 11:31:34 pmDoesn't address which data to use for the "actual rate" in my context.
Battery capacity tester adc resolution question - Page 1
Forum section: electronics / projects

author: kjr18
author_rank: Regular Contributor
timestamp: March 07, 2019, 09:38:22 am
content: Hi, I want to make a battery capacity tester, mainly as a training exercise, as well to use it. It will be only used for AA, AAA and maybe some small li-ion or li-poly cells. I plan to use for this purpose a simple constant current circuit consisting of two opamps, you could say: textbook example. Arduino will be responsible for counting capacity etc.My question concerns ADC resolution: I know that typical arduino's adc resolution is about 5mV (from 0 to 5V), and if I were to, let's say, connect analog input straight across a load resistor, I would have some error in measurement. It's not much, but what if I wanted to use that measurement to calculate total mAh of the cell? Won't that error accumulate over time? I thought about some other possibilities, like using external higer resolution adc, or using something like INA219 to take care of both battery voltage and current measurement (connect it to load resistor or add small 100mR in series with load resistor). What solution would be the best, also price wise, I don't want to go broke because of this
Battery capacity USB monitor - cheap way to monitor a battery pack (maybe) - Page 1
Forum section: electronics / projects

author: ez24
author_rank: Super Contributor
timestamp: August 21, 2016, 11:11:44 pm
content: I was looking for a USB monitor to just look at the amps and came across this:https://www.aliexpress.com/item/Digital-Dispay-3V-30V-Mini-Current-Voltage-Charger-Capacity-Tester-USB-Doctor-qc2-0-3-0/32686482158.html?spm=2114.01010208.3.67.cgXydy&ws_ab_test=searchweb201556_0,searchweb201602_4_10057_10056_10037_10055_10054_301_10059_10033_10058_10032_10017_10060_10061_10052_414_10062_10053_413_10050_10051,searchweb201603_9&btsid=29b26a51-3d2c-46a9-b709-e180d38e55a8I wonder if anyone has used one of these. It is hard to understand what this really can do. If it can keep track of the "capacity" of a battery (or batteries) then this looks like a cheap solution. I have seen monitors that cost $100s (for RVs). Of course this is for much lower currents.Since this is rated at 5.1 amps (very strange rating), this might work at 2 amps. Maybe a charge of 3 and discharge of 2 ?If anyone has used one, please include a link to it.

author: eas
author_rank: Frequent Contributor
timestamp: August 22, 2016, 01:26:24 am
content: From what I can tell, that's basicallythis device, without the QuickCharge triggering functionality.

author: HKJ
author_rank: Super Contributor
timestamp: August 22, 2016, 12:59:12 pm
content: Here is the review of it:http://lygte-info.dk/review/USBmeter%20safety%20tester%20J7-t%20UK.htmlBut I do not really explain about the mAh and Wh, but it is just a summation of mA and W values.It is often used to measure capacity of power banks with or how much capacity is needed to charge a phone.

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 04:21:07 pm
content: Quote from: HKJ on August 22, 2016, 12:59:12 pmI agree but I was glad to find that web site, I lost it, so I will look around at his other stuff.Here is one with an audible alarmhttps://www.aliexpress.com/item/high-quality-QC-2-0-3-0-USB-Charger-safety-Tester-with-alarm-device-4-0/32670667507.html?spm=2114.13010208.99999999.275.Z2ArGZI am trying to order these but can't get my order through Aliexpress
Battery cell balancing technique, review it? - Page 1
Forum section: electronics / projects

author: HSPalm
author_rank: Regular Contributor
timestamp: September 17, 2019, 12:06:59 pm
content: Hello,I have reviewed some different circuits for balancing battery cells, but I have not seen any using the technique I propose here. Would like to discuss any downsides and benefits, maybe if you see some obvious errors that I don't see.Each cell can be individually connected to either VDD or GND, except the top or bottom cells of course.When charging the full pack, you close the top and bottom switch and operate VDD in constant current mode. When one (or more) cell(s) reach full charge voltage, you start the constant voltage charge mode until charge current is equivalent to a complete charge. If any cell is out of balance, you adjust VDD output and charge it individually as shown in the one screenshot.VDD or the charge voltage/current will be controlled by a fet in linear mode, so the switches can actually remain switches (relays or fets operated as switches).This is a list of downsides and benefits I've discovered so far.You can charge the unbalanced cell(s) with the full current of the charger. Balancing current is often limited in other chargers.You can only balance one cell at a time, unless the unbalanced cells are adjacent.You must wait to balance until the full pack is charged.Transistor count is high.
Battery cell emulator - Page 1
Forum section: electronics / projects

author: Blackgar
author_rank: Contributor
timestamp: February 28, 2022, 07:56:27 pm
content: Could you suggest any battery cell emulator for x12 Cells (or more) that you had any experience with?It will be used for testing on a custom BMS system with active balancing method of max 5A charge/discharge currents.Later it will be part of the HIL implementation.

author: m k
author_rank: Super Contributor
timestamp: March 01, 2022, 04:34:59 pm
content: Seems to be a bit limited section, sort of a wrong end of the community.I guess you must do it your self from scratch anyway so maybe you can put up some updates.
Battery charge controller and DC-DC in one package - Page 1
Forum section: electronics / projects

author: Boomerang
author_rank: Regular Contributor
timestamp: March 07, 2017, 01:11:56 pm
content: Is there one IC to solve the two problems: Lithium ion cell babysitting and generating from it stable DC power output?What I need is really small output power ( < 0.5 W ) and charging from standard 5V USB connector.

author: cyberfish
author_rank: Regular Contributor
timestamp: March 07, 2017, 01:18:44 pm
content: Quote from: Boomerang on March 07, 2017, 01:11:56 pmWhat do you mean by babysitting? If you just mean charge and terminate charging correctly, there are many options. Eg. MCP73831If you need things like over-current and over-temp protection, maybe even coulomb counting, you'll have to look for a battery management chip -http://www.ti.com/lsds/ti/power-management/battery-management-products-overview.pageThose are a lot more complicated.

author: Boomerang
author_rank: Regular Contributor
timestamp: March 07, 2017, 01:38:19 pm
content: Charging (start, stop), overcurrent protection, deep discharge protection and that's all. I don't need coulomb counting, capacity or wear level measurement and etc...

author: grifftech
author_rank: Frequent Contributor
timestamp: March 07, 2017, 03:37:18 pm
content: buy a cheap power bank and use the board from it.

author: mvdswaluw
author_rank: Contributor
timestamp: March 07, 2017, 05:02:20 pm
content: Quote from: grifftech on March 07, 2017, 03:37:18 pmNot one chip, but have you considered looking at a Adafruit powerboost?

author: Fungus
author_rank: Super Contributor
timestamp: March 07, 2017, 05:10:14 pm
content: You want to manufacture hundreds or do you just need a handful?If you only need a handful then eBay is full of modules, eg:http://www.ebay.com/itm/122217973743

author: cyberfish
author_rank: Regular Contributor
timestamp: March 07, 2017, 05:12:26 pm
content: Quote from: Boomerang on March 07, 2017, 01:38:19 pmI don't think I have seen a chip that does charging and also monitoring. There is always a one-chip solution though - use a microcontroller.

author: trophosphere
author_rank: Frequent Contributor
timestamp: March 08, 2017, 12:33:17 am
content: Quote from: cyberfish on March 07, 2017, 05:12:26 pmThis one from Linearis the only one I was able to find that does charging and has a over discharge disconnect functionality.In regards to the original poster, thebq2501x Seriesfrom TI has lithium ion charging and a built-in DC-DC buck converter. No protection from over discharge built in though.

author: Boomerang
author_rank: Regular Contributor
timestamp: March 08, 2017, 09:10:39 am
content: Quote from: trophosphere on March 08, 2017, 12:33:17 amThanks a lot! This is exactly what I'm looking for! I spend hours of searching on TI web site and didn't found it...
Battery Charge Equalizer System (MSC-TOPS-35) by NASA (patent) - Page 1
Forum section: electronics / projects

author: szan
author_rank: Regular Contributor
timestamp: September 29, 2021, 11:24:18 am
content: I've already found this interesting article on NASA web pages:Battery Charge Equalizer System (MSC-TOPS-35)Extending battery life and performance in large battery arrayshttps://technology.nasa.gov/patent/MSC-TOPS-35"...The system is ultra lightweight because it uses much fewer than one transformer per battery cell. For instance, 40 battery cells can be balanced with an array of just five transformers. The innovation can charge an individual cell bank at the same time while the main battery charger is charging the high-voltage battery system. Conventional equalization techniques require complex and costly electrical circuitry to achieve cell monitoring and balancing...."https://ntts-prod.s3.amazonaws.com/t2p/prod/t2media/tops/pdf/MSC-TOPS-35.pdf?! Maybe someone tried this how it works and performs in practice ?!Regards.Szan.

author: Haenk
author_rank: Super Contributor
timestamp: September 30, 2021, 08:48:07 am
content: https://patents.google.com/patent/US8896315B1/enLooks like this is a decade old and they are more or less just switching through a matrix of cells.
battery charge state monitor green/yellow/red/blinking - Page 1
Forum section: electronics / projects

author: not1xor1
author_rank: Frequent Contributor
timestamp: August 22, 2017, 04:25:39 pm
content: Somebody in it.hobby.elettronica (i.e. Italian newsgroup of electronics) asked for a circuit to monitor the state of charge of a 5 Ni-MH batteries pack.The circuit should use a bicolor led featuring a green light for full charge, green+red for intermediate charge, red for low charge and blinking red for lower level of charge.The circuit below uses a low power quad opamp (TLC27L4) and a low power reference voltage (LM385 or LT1004-1.2) and according to LTSPICE should work as expected showing a green light when the voltage is above 6V, green+red (yellow?) when it is between 5.5V and 6V, red when it is greater than 5V and a blinking led light when the voltage is below 5V.Possible modifications include the more common LM385 instead of LT1004-1.2, 2N7000 or any other low power NMOS, the led series resistors might be increased or adjusted to get a better blend of red and green or to reduce current consumption, multiturn trimmer to adjust the threshold voltages, etc...Please feel free to comment.
Battery charger circuit design - Page 1
Forum section: electronics / projects

author: Nikolas
author_rank: Newbie
timestamp: May 20, 2020, 03:47:17 pm
content: Hey, so I am trying to design and build my own battery charger for 4 cell LiPos (including HV-LiPos with 4.35v/cell) but I don't have a lot of experience with circuit design.I designed this circuit so that it can either supply a constant voltage or constant current to the battery with the other one being a backup.I use OPAMP_current and OPAMP_voltage to control the corresponding mosfets, with the reference voltage being supplied by DACs which will be controlled by a microcontroller.For measuring current I use a small resistor in series with the load and a current-sense-amplifier which amplifies the voltage drop across that resistor.For measuring voltage I use a voltage divider.Since both measurements are sensitive to loads being applied to them I use additional opamps as voltage followers and read their outputs with the microcontrollers ADCs.The 100ohm resistors across the inputs of the control opamps are there to limit the overshoot for example when the battery suddenly gets disconnected. (found that idea on the internet and it works in simulation, not sure if it's a good way to do that though)Regarding balancing of the cells, I will probably just copy one of those balancing boards that you can get for a few bucks on ebay.My question is, would this circuit work the way it is and if it would, are there any things missing that would improve reliability or are just good practice?Thank you,Nikolas
Battery charger IC 10 lithium cells in parallel - Page 1
Forum section: electronics / projects

author: Unordung
author_rank: Contributor
timestamp: May 30, 2021, 04:18:11 am
content: Hi guys,I'm looking to build a device which uses 10 18650 lithium cells in parallel.I can find a ton of <2A charger IC's but nothing closer to the 5A im looking for not with an English Datasheet anyway.Can anyone recommend a good charging IC / BMS for such a battery?Cheers.

author: amyk
author_rank: Super Contributor
timestamp: May 30, 2021, 04:28:19 am
content: Better to charge each one individually. That way you won't need to deal with balancing as each one will be independently charged from the others.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 30, 2021, 04:51:06 am
content: Quote from: amyk on May 30, 2021, 04:28:19 amDoesn't apply if they're in parallel and will stay that way once the pack is assembled.You might want to look at fast charging chipsets for smartphones, but they'll almost certainly be in very difficult to work with SMD packages. I would say to use a standard buck converter with current limiting set to 4.1V and 5A or whatever your target current is, then add a MOSFET to only connect the output when charging.

author: wraper
author_rank: Unknown
timestamp: May 30, 2021, 07:07:28 am
content: It's a territory for ICs which use external MOSFETs.
Battery Charger with LTC4006 design question - Page 1
Forum section: electronics / projects

author: Write_to_Smokegenerator
author_rank: Regular Contributor
timestamp: October 30, 2012, 11:58:39 am
content: Hello everyone,A friend and I are currently designing a battery charger for our project.After some work we finally nearly finished the layout and wanted to start printing the layout but a question occured:Place inductor input as close as possible to switchingFET’s output connection. Minimize the surface area ofthis trace. Make the trace width the minimum amountneeded to support current—no copper fills or pours.Avoid running the connection using multiple layers inparallel. Minimize capacitance from this node to anyother trace or plane.- Design guidelines from the LTC4006 datasheethence: under the switch node section: PH7030L, TPC8128,L1, D1 can there be a ground plane or would it be better not to have one?If you look at the attached picture we did a copper fill at the node but it would be as if we would use a wire because it all is as short together as possible, do you think that also could make some errors or is it neglectable?also do you see other design issues if so please let me knowEdit 1: PS our inductor is shielded.Edit 2: it seems near the C5 Cap we need a via.Edit 3: here is the link to the LTC4006 datasheet:http://cds.linear.com/docs/Datasheet/4006fa.pdfstating page 17 are the design guidelinescheers.

author: jeroen74
author_rank: Frequent Contributor
timestamp: October 30, 2012, 08:43:32 pm
content: A quick google indicates LT has a demoboard for this IC. Check it out, as the documentation usually contains images of each PCB layer.
Battery Charger with microcontroller - Page 1
Forum section: electronics / projects

author: gascencio
author_rank: Newbie
timestamp: November 03, 2022, 02:52:50 pm
content: Hi,I'm working on a project and i'm looking for a component that could fit this architecture :I would like to do the following:When the 5V input is ON, the charger acts as a pass through and charges the battery if neededWhen the 5V input is OFF, the charger boost the battery voltage to a stable 5VThe microcontroller can cut the boost and go OFF for an undetermined time spanI found the MP2696, but by default, it's not set as pass through ( transistor Q2 OFF) so it's kind of like chicken and egg:microcontroller must be turn on to set Q2 on but Q2 must be ON so the microcontroller gets the powerIf anybody has any idea/ component replacement or variation to the architecture to make it workThanks

author: Peabody
author_rank: Super Contributor
timestamp: November 03, 2022, 05:04:16 pm
content: You might want to review this thread on the TP5400 and TP5410:https://www.eevblog.com/forum/projects/load-sharing-on-a-tp5400-(lipo-charger-boost-converter)/That chip has a similar problem in that the output drops to the battery voltage less one schottky drop when 5V is plugged in. In that thread he uses an added schottky diode from VBUS to Vout to provide the needed power path. That would make Vout 4.7V. If that's too low, you could replace the diode with a mosfet. But you could do that with any such charge/boost chip if the needed load sharing isn't built in.I'm not sure about the need to turn off the boost converter. The only time it might be running needlessly is when 5V is plugged in, and then it doesn't really matter. The TP5400 actually disables the boost converter whenever 5V is connected, even after charging has terminated. I don't know about your MP2696.
Battery Charging Algorithm-Confusions - Page 1
Forum section: electronics / projects

author: Siddhat
author_rank: Regular Contributor
timestamp: July 05, 2020, 05:46:46 am
content: Hey guys!I've been designing a battery charger for a 12 Volt 7.8 Ah sealed lead-acid battery following the CCCV algorithm. The algorithm states, charging the battery at a constant current while the battery voltage rises. The current starts to drop as the battery voltage rises. As the battery voltage rises and reaches the gassing voltage, the charger now goes into a intermediate mode which maintains the voltage of the battery at the gassing voltage. The current starts to drop and when the current reduces to a certain percentage of the Amp-hour rating (determined by the manufacturer), the battery needs to be charged in a float voltage, which is the Constant Voltage mode of the charger. Usually the float voltage is lower than the gassing voltage.But there are some confusions! How can a battery whose voltage has reached the gassing voltage be maintained at a lower float voltage? This seems strange. Need some explanation.

author: Nusa
author_rank: Super Contributor
timestamp: July 05, 2020, 06:40:12 am
content: Do an experiment. If you remove the charger, what's the battery voltage? Does that answer your question?Also, you don't want to actually reach the gassing voltage on a sealed battery, just get close. If they start venting, you can't replace it. On a battery where you can check and top off the water levels it's less critical.

author: trobbins
author_rank: Frequent Contributor
timestamp: July 05, 2020, 07:37:06 am
content: Siddhat, I recommend you google and read up on as many technical articles about VRLA batteries as you can, including from large battery manufacturers that include operating instructions for their batteries.That way you will gain some experience about what variety of charge profiles may be being recommended by different manufacturers, and for what applications (eg. standby, UPS, cycling, intermittent charging, PV, traction, anything and everything in between).Then read some operating manuals of a few commercial chargers to get a feel for how they approach the topic - some provide a list of different charge profiles with the ability to set parameters associated with various stages within a profile.The information is all out there.Also note that a charger must only allow output current to flow in one direction, and many chargers use a series diode to enforce that spec. So if your charger changes its command level for output voltage from say 14V to 13V, then initially the charging current will fall to zero as the battery voltage relaxes back to its open-circuit voltage level. Assuming 13V is still above the OCV then at some time the charger current will start to increase from zero again. So you need to read up on OCV and how that changes, and look at charge discharge voltage curves, and discussion about the chemistry of that type of battery, and look for some experimental graphs of voltage and time.
Battery Charging IC for Li-ion Battery Pack - Page 1
Forum section: electronics / projects

author: ejht
author_rank: Newbie
timestamp: October 04, 2021, 01:46:41 pm
content: Hi,It might sound like a stupid question, but I am struggling with this.I am looking for a battery charging IC that manages the battery requirements of my project, but I am not certain if I can use a one cell battery charger IC, such as thehttps://www.ti.com/product/BQ25300] https://www.ti.com/product/BQ25300, since the battery pack that I am looking are 3 cells in parallel (for examplehttps://docs.rs-online.com/ae2f/0900766b8163e9c9.pdf).I have been looking for an IC that handles multiple cells, but it is always refered to serial connection, and therefore the voltage stated for the configuration are higher than 4.7v (like the battery pack commented)Thank you in advance

author: tooki
author_rank: Super Contributor
timestamp: October 04, 2021, 05:17:42 pm
content: Yes, you can parallel the cells. (I did that with the BQ25895 in a recent project.) The important thing is for the cells to be well matched, so you want cells from the same lot, and never, ever replace them individually. In a purchased parallel pack like the one you showed, this is taken care of.
Battery Compartment Connector for Sony A7R series camera - Page 1
Forum section: electronics / projects

author: gnif
author_rank: Unknown
timestamp: August 19, 2023, 10:46:42 pm
content: Hi All,I am looking for a recommendation on a PCB mount part (preferably through hole) I can use to replicate the pins on the side of the battery in the attached image. They look like some form of pogo pin, which pushes up against some pads inside the battery compartment.This is for an ongoing project to create a battery extender/grip as seen here:https://www.thingiverse.com/thing:6159253I would like to see if I can get access to the shutter release button.
Battery compartment with switch & DC connector, panel mounted - Page 1
Forum section: electronics / projects

author: ebastler
author_rank: Super Contributor
timestamp: January 01, 2025, 01:28:21 pm
content: For a hobby project I am planning, it would be quite convenient to have an off-the-shelf battery holder (3*AA or 3*AAA) complete with on/off switch and external DC connector (e.g. barrel type, switching off the battery supply when a plug is inserted). The whole thing should be prepared for mounting in a back panel, using screws or molded retaining clips/tabs. I.e. the battery lid, switch and connector must all face the same side, and it should be possible to open the actual battery compartment while the total assembly/frame remains installed in the panel.This seems like an obvious and useful piece of kit. But I did not find anything at the usual sources, i.e. major distributors, hobby shops, AliExpress. All I can find are little boxes where I am not sure about the use case -- apparently they are supposed to dangle loosely on their two flimsy wires? Not suitable for my intended mounting scheme since the switch is on the side of the box, and they don't have a DC connector.If you have come across such a gadget suitable for panel mounting, many thanks for pointing me in the right direction!

author: BILLPOD
author_rank: Frequent Contributor
timestamp: January 01, 2025, 01:56:41 pm
content: Good Morning Eblaster, Here is something that looks like you can adapt it to fit:https://www.amazon.com/LAMPVPATH-Battery-Holder-Switch-Leads/dp/B07C6XC3MP?dib=eyJ2IjoiMSJ9.dB1ogq6a3r6B8It9fxhY-vLqGOAdOPTLUpIX67ruBNRCNSjrTHP3Qq9r_oHTwYuWfp1cONfhXf46C87lPFhIIPsBK2UAuZPD0YpaxtAJVdBGp2WzrzTHGcWyfY0fy8Vywi2NygvccyKP6qQON3ZO-JKzsThPlcz4rh8_vRHz5ziMzBVZMyPEHC-QjJ44QSvEyxmrkPy6tYJcHJgQbGmZaVRfXTJGplIw59ge2t0Z2tE.Nf3lP7yPrU6mhmy6CVpqjGs0xa7GJTHsDDNPe2y32SE&dib_tag=se&keywords=4.5v+battery+pack&qid=1735739603&sr=8-3
Need a Certain Sized Battery Pins/Tabs - Page 1
Forum section: electronics / projects

author: tesla01
author_rank: Newbie
timestamp: August 24, 2014, 11:52:04 pm
content: Hi everyone! Long time lurker, first time poster here. I have a little project I'm working on that I thought maybe you guys could help me with.Recently my Pulsonic electric toothbrush stopped working. Unfortunately I'm a little over my warranty period now and didn't want to pay for a costly replacement. Now being a tinkerer, I disassembled the toothbrush and tested the rechargable battery. It appears that it's dead and won't hold a charge anymore - a common problem with these toothbrushes. The battery is soldered on, which isn't an issue for me. I have a soldering iron and decent skill to desolder the existing pins and replace the battery. I also was able to narrow down an after market battery that has similar voltage, size, and current.See the battery here:http://media-cache-ec0.pinimg.com/736x/7c/15/81/7c158193da1c888324f38fe031b5b8d5.jpg(Tenergy 3.7V 800 mAh)Now you can get these with or without tabs/pins. I bought one but the tabs they come with though are too wide and not long enough. So the issue is either finding a supplier for the correct pins or finding an alternative way to solder the battery to the PCB. If I were to find the right pins, I'd be soldering them on to the leads. I understand that this can be dangerous, but I think I can be careful and move the iron away before the battery heats up for too long.Here's a picture of a similar battery with the right pins:http://oi59.tinypic.com/154c0hy.jpgThe two joints that need to be desoldered:http://oi62.tinypic.com/24giyyr.jpgOpposite view:http://oi60.tinypic.com/dyvmdh.jpgThe PCB with the battery fitted in, before soldering:http://oi57.tinypic.com/2gvm1wp.jpgDoes anyone know where I could find similar pins or if there is an alternative way to attach the battery? I'd really appreciate your help. Thanks in advance

author: DanielS
author_rank: Frequent Contributor
timestamp: August 25, 2014, 01:20:55 am
content: If your only problems are that the tab is too wide and short, you can simply solder a piece of wire from the PCB to the battery's tab. The toothbrush's motor likely draws less than 3A so #26 wire should be more than good enough for such a short run.

author: tesla01
author_rank: Newbie
timestamp: August 26, 2014, 07:35:58 am
content: Quote from: DanielS on August 25, 2014, 01:20:55 amI'm going to try that Daniel, thanks!
Battery contacts inside a molded case - Page 1
Forum section: electronics / projects

author: msr
author_rank: Regular Contributor
timestamp: June 15, 2015, 02:27:43 pm
content: Hi,I'm for the first time designing a PCB that will fit inside a molded case and I'm not sure how I'll connect the batteries (2xAAA in series) to the PCB.The batteries are connected in series and should be placed side by side and in opposite directions so I'll get the (-) and (+) of the "overall battery" on the PCB side. The "other side" is the cover which also has contacts (spring + flat contact) and connects the batteries in series.My question is: what kind of battery contacts should I use on the PCB side? "SMD/PCB mounted contacts" or "contacts inserted in mold + wires to PCB".What offers more reliability and what's easier and cheaper to manufacture? What do you think?

author: LabSpokane
author_rank: Super Contributor
timestamp: June 15, 2015, 02:49:36 pm
content: You get to pick your manufacturing defect with this one.Soldered to the PCB is usually cheapest in the western world. If you manufacture in China, the labor may be so cheap that it may not matter. Personally, I would avoid soldering wires, since the wires usually fail at end of the insulation. However....The downside of large contacts (or any large mass) getting soldered direct to the PCB is cold solder joints that crack in service. A lot of assembly houses will take the shortcut and not preheat the components before soldering. This is an issue that affects everything from consumer products to $2000 radios.No matter what, your QC folks will be inspecting in the quality at some point.
Battery cycle test system for 48V Lithium-ion - Page 1
Forum section: electronics / projects

author: voltsandjolts
author_rank: Unknown
timestamp: July 18, 2025, 08:12:06 pm
content: So, I need automated test equipment for cycling 48V lithium packs, 300Wh-ish, around 4A charge/discharge rates is fine. Now, I could likely make something from a psu and electronic load, both remote controlled from some python code. But from safety point of view there are risks to consider, e.g. if pack protection circuits are faulty and then the control PC freezes or such like. Battery could then be overcharged or overdischarged, damaging the battery, or worse, causing a fire. So there needs to be hardware protection features for that built-in to the ATE. It's more work than python+psu+EL.So, there must be such ATE available off the shelf, but I can't find much...There are expensive battery testing systems available, such ashttps://www.matsusada.com/product/battery-cycle-tester/cdpu/but that's way more than I need.Anyone got any experience or recommendations for battery cycle testers?

author: thm_w
author_rank: Super Contributor
timestamp: July 18, 2025, 10:55:59 pm
content: IT6433 or IT-M3412 might be relevant.https://www.eevblog.com/forum/testgear/buying-advise-for-a-2-quadrant-benchtop-power-supply/https://www.eevblog.com/forum/testgear/battery-testing-instruments/There is built in overvoltage protection, if you don't trust that, you can have a simple external monitor circuit that shuts off a relay that powers the unit or something.Overdischarging I wouldn't really worry about.If there is a problem with your BMS better that you find out about it instead of babying the unit.

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 19, 2025, 02:38:59 am
content: Have you considered an "inverter/charger" of the type used in RVs and other alternative energy setups? Even the smaller ones might be overkill for your use but might still be the cheapest option that is specifically designed to charge and discharge batteries.

author: Smokey
author_rank: Super Contributor
timestamp: July 19, 2025, 03:09:30 am
content: Any lab power supply with modern cv/cc modes would work. Set voltage to charge voltage and current to charge current. All is handled in the hardware of the supply. When the battery is fully charged the supply ends in constant voltage mode and the current tails off to nothing.If you are really paranoid, pick a supply with an absolute over voltage trip and set that too.I would not have a problem automating battery cycles with a supply + load + python.There are a bunch of 2-quadtant supplies out there that could do both functions. I only have stuff that goes to 30vish though.

author: voltsandjolts
author_rank: Unknown
timestamp: July 21, 2025, 07:20:30 pm
content: Quote from: thm_w on July 18, 2025, 10:55:59 pmThanks for the pointer to ITECH, they have a suitable 400W two quadrant psu and quote is under 2K. That's a strong contender.
battery desulfating & multiple batteries. Or keeping pulses from going upstream - Page 1
Forum section: electronics / projects

author: ja421
author_rank: Contributor
timestamp: September 29, 2016, 10:40:51 pm
content: I do not claim to be an expert, but I have read and experimented a fair bit over many years) with battery desulfators (and marginal batteries); while I don't swear by them, I do like to use them on batteries that are stored or being charged. I am using a variation on the original magazine version. I have recovered more than a few batteries; making the desulfators pay for themselves.What I understand is that it's better to have the desulfator close to the battery, closer the better, with short leads. This means that float charging needs multiple chargers as the desulfators need to be close to the battery and can't share a charger, as this would move the desulfator farther away.The question is: is there a way to charge multiple batteries from one source while having individual desulfators on each battery? (while keeping one battery's frequency from interfering/minimizing the frequency of another) Would a simple diode w/ capacitor on (charger side) upstream of desulfator keep the interference down sufficiently?The reason for one charging source is space, desulfator is small while charger is bigger. If keeping the frequency/pulses at the battery and not going back upstream is not a simple prospect, then I will work on making smaller chargers.Thanks.

author: tautech
author_rank: Super Contributor
timestamp: September 29, 2016, 10:50:43 pm
content: Done a bit of this myself.These days however many of the more advanced smart chargers have various sorts of batteryconditioninginbuilt.Yes it's a good idea IME but it's not the only trick I use now for battery maintenance.Flooded LA's do respond well to equalization (gassing) charge and these days that is my prefered treatment.However there is something quite neat when overnight the OC voltage of a batteryincreasesafter a session of desulphation.