Boilerplate USB single Lithium cell battery power supply for DIY projects - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: February 08, 2022, 06:36:45 pm
content: Lithium Li-ion 18650 3.7V 4.2V Battery Charger Board DC-DC Step Up Boost Module TP4056as sold this Module see imagehas anyone added a soft latch power switch circuit to this particular USB battery board DC-DC step Up boost module?if so? can we see your reverse engineering work of this particular boost module?whyso we can have an auto power off at low Battery & a soft latch power switch for the step Up boost part of the circuit.the idea here is to have a single Li-ion 18650 with USB Charger and power 50 to 200Ma 6 to 9 volt projectsboilerplate USB battery power supply circuit for 6 to 12 volt projects with its own soft latch power switch .I have seen and know about soft latch power switch circuits, Dave did a video on them.so how would you go about modifying this particular USB battery board DC-DC step Up boost module?I would cut in to the power rail tracks on the PCB in between the TP4056 battery charge part of the circuit Aand the DC-DC step Up boost part B of the on the PCB and add a power MOSFET & two npn in a soft latch.but the part I do not know, is the best way to trip off any modified soft latch circuit when the battery gets low.so if any of you have reverse engineered this module?can pin 8 on the TP4056 be used as an On Off switch? so no auxiliary power MOSFET is needed simplifying a soft latch power switch.my USB TP4056 boost modules are still in the post & no one online has reverse engineered the circuit as far as I know.

author: Peabody
author_rank: Super Contributor
timestamp: February 08, 2022, 09:41:45 pm
content: I have one of these modules, but haven't had a chance to play with it. You may find more information by searching for "J5019 module". The mystery chip is an MT3608. The module has no protection function, so you would have to add that or use protected batteries. There are three plated-through holes near the output headers, but I don't know what purpose they have.In addition to protection, the module is also missing a power sharing circuit (also known as power path).I agree that the best place for the soft latch circuit is between the battery + terminal and the input to the boost regulator. You want to be able to charge the battery while the load power is switched off.

author: thm_w
author_rank: Super Contributor
timestamp: February 08, 2022, 10:49:25 pm
content: I use the dedicated MT3608 module then USB charger + protection in one board, with a hard power switch on OUT+, from what I remember:https://www.aliexpress.com/item/32649780468.htmlhttps://www.aliexpress.com/item/4001066566291.htmlThere is probably a way to logic level trip the DW01 used on those boards, but, I didn't consider that method.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: February 09, 2022, 08:39:49 am
content: Information on a typical protection board with Ali.

author: JohanH
author_rank: Frequent Contributor
timestamp: February 09, 2022, 09:47:03 am
content: MT3608 pin 4 EN is probably connected to incoming voltage to DC converter. You could cut the trace and use pin 4 to enable/disable the converter (min. 1.5V to enable).

author: kjr18
author_rank: Regular Contributor
timestamp: February 09, 2022, 07:30:15 pm
content: This board is simply two circuits from data-sheet's slapped together. Those three plated holes are for connecting external pot, if you want more precise voltage control (that smd pot is so tiny). I don't think that EN pin will do what you want, only thing that will change is that ic will stop switching, resulting in output voltage around input voltage with some voltage drop on shottky diode.I think it's better to use separate modules, one with battery protection, and boost with 10 turn pot. You could even add some additional circuit if you want to let's say charge battery and use boosted voltage at the same time. With this module you have, you might have some problems with charging battery as boost circuit is connected straight to battery, and charging could never terminate properly.

author: JohanH
author_rank: Frequent Contributor
timestamp: February 09, 2022, 08:03:43 pm
content: Quote from: kjr18 on February 09, 2022, 07:30:15 pmYou are most likely correct here.Quote from: kjr18 on February 09, 2022, 07:30:15 pmAgree.

author: jonovid
author_rank: Super Contributor
timestamp: February 09, 2022, 09:06:50 pm
content: Quote from: jukk on February 09, 2022, 08:03:43 pmAgree.Im open to experimentationQuotecan a bypass diode be used on the TP4056?so the higher USB 5 volts can power the MT3608 directlywhen the battery is charging. boost circuit is lifted off the battery by the 5 volts bypassbe interested in the design of a better mousetrapMT3608TP4056DW01-Padd MOSFET soft latch power switchwith low battery auto shut offelectronoobs of yt did a video about this type of USB battery circuitBattery Charger & Protection & Boost 5V or 12Vbut he did kill a MT3608 with a poor design of a voltage setting switch in his own PCB design.why he did not run the two resistors in parallel to pin 3 of the MT3608 & just switch out the lower value?https://electronoobs.com/eng_circuitos_tut49.phpif I ever get into doing PCB design this is the type of circuit I would get made-can never have too many of them as a hobbyist.

author: Peabody
author_rank: Super Contributor
timestamp: February 09, 2022, 10:21:36 pm
content: The first circuit below is the standard "load sharing" or "power path" circuit. It would permit USB to power the load directly when plugged in, and charge the battery to proper termination independently. But it's essentially a three-module circuit, and doesn't yet have any soft start function, which would probably go where the manual switch is shown. The second circuit is an example soft start circuit which allows the switch to be used as input after power has been turned on.

author: thinkfat
author_rank: Unknown
timestamp: February 10, 2022, 09:56:41 am
content: Maybe you can use the TP5400, if you add a protection circuit and some load sharing / power path. The TP5400 combines a 1S charger with a boost converter. You can find a lot of modules on ebay using this chip (or the mostly identical TP5410).

author: Peabody
author_rank: Super Contributor
timestamp: February 10, 2022, 03:29:57 pm
content: There's a Great Scott video on a TP5410 module. He found several shortcomings, including lack of any battery protection.

author: jonovid
author_rank: Super Contributor
timestamp: February 11, 2022, 06:43:57 pm
content: just found this lot of module strips in my parts bins of a 2017 vintagewhen they was cents in the dollar so you'd buy a strip of 5 or 10 at a timeone strip is Li-lon battery charger with protection chipthe others are Li-lon battery DC to DC set to 5 volt converter USB powermini modules DC to DC 3.3volt for a never completed drone camera set-up. dander & hair in the image is from the cat.only used 3 modules back in 2017something to play with no excuses now