Li-Ion Charger B+/B-/OUT connections and low voltage protection

TECHNICAL SUPPORT Batteries & Power
1

Customer:

I just connected the charger and have a few questions about it (product 101408). If there are differences compared to product 222007, please mention them.

  1. I assume the battery connects to B+/B- and the load to OUT+/OUT-? I’m sure about the battery but not about the load.
  2. If my assumption above is correct, can the load be connected during battery charging and does it then power from the battery or from the source?
  3. Are pins B+ and OUT+ short-circuited or controlled separately by the electronics?
  4. If they’re short-circuited, how does low voltage protection work when the load is permanently connected to the battery? Or does low voltage protection mean something else? Of course, this question only makes sense if OUT is intended for the load.
  5. Can I charge a single Li-Po cell with this charger? As far as I know the voltages are the same, only the charge detection algorithm differs, the so-called delta peak.
  6. Some batteries in the shop (for example 101383) look like Li-Po even though they say Li-Ion. Is that actually Li-Ion or is it perhaps a mistake? I’ve never seen a Li-Ion that wasn’t in a metal case, and on the other hand Li-Po that wasn’t like in a pouch, but that doesn’t mean I’m right.
Original message (Croatian)

[name removed] bok!
Tek sam sada spojio punjač pa imam nekoliko pitanja. Radi se o punjaču koji više ne nudiš (101408). Ako postoji razlika u odnosu na punjač 222007, napiši i nju.

  1. Pretpostavljam da na B+/B- spajam bateriju, a na OUT+/OUT- trošilo? Za bateriju sam siguran ali ne i za trošilo.
  2. Ako je moja pretpostavka na prethodno pitanje točna, smije li trošilo biti priključeno u trenutku punjenja baterije i napaja li se onda iz baterije ili iz izvora?
  3. Jesu li pinovi B+ i OUT+ kratko spojeni ili ih elektronika posebno kontrolira?
  4. Ako su kratko spojeni kako radi zaštita od preniskog napona kada je trošilo trajno spojeno na bateriju? Ili se zaštita od preniskog napona odnosi na nešto drugo? Naravno, ovo pitanje ima smisla ako je OUT predviđen za trošilo.
  5. Smijem li s tim punjačem puniti jednu ćeliju Li-Po? Koliko znam naponi su im isti jedino im se nešto razlikuje algoritam detekcije napunjenosti, tzv. delta peak.
  6. Neke baterije u shopu (npr. 101383) izgledaju kao Li-Po premda piše Li-Ion. Je li to stvarno Li-Ion ili je možda lapsus? Nisam vidio Li-Ion a da nije u čeličnom kućištu, a s druge strane Li-Po koji nije kao u jastuku, ali to ne znači da sam u pravu.
    To je to.

Originally submitted via email support on 31 May 2018. Migrated to the forum for community visibility.

2

Soldered Support:

There is no difference between the two chargers - except that this one is Made in Croatia and has a JST connector and jumpers for easier adjustment of charging current.

  1. Yes, that’s right! Battery on B+/B-, load on OUT+ and OUT-.
  2. The load can be connected at all times. If a battery is present, it is powered from the battery. If there is no battery, it is powered from the source (true, a bit less efficient, but it works).
  3. Short-circuited. The electronics control the negative side.
  4. Low voltage protection works by disconnecting B- from OUT- when the battery voltage is below a certain threshold. When you connect the charger which brings the voltage above that level, the protection deactivates.
  5. Yes, Li-ion / Li-Po are almost the same thing, as you yourself said.
  6. Li-Po and Li-ion differ internally by the materials used. We requested Li-ion from the manufacturer and they offered it, but in the datasheet they wrote “Lithium-ion Polymer” Soldered: Open-Source Electronics, Boards, Sensors & Modules – Soldered Electronics so all I can say is “who knows” - you’re probably right. I’ve noted this down so I’ll check it once and update it.
Original message (Croatian)

Hej! nema razlike između ta dva punjača - osim što je ovaj Made in Croatia i ima JST konektor te jumpere za jednostavnije podešavanje struje punjenja. 1. Da, tako je! Baterija na B+/B-, trošilo za OUT+ i OUT-. 2. Trošilo smije biti priključeno uvijek. Ako je baterija prisutna, napaja se iz baterije. Ako nema baterije, napaja se iz izvora(istina, malo neefikasnije, ali funkcionira) 3. Kratko spojeni. Elektronika kontrolira minus dio. 4. Zaštita od preniskog napona funkcionira tako da odvoji B- od OUT- kada je napon baterije ispod određen threshold-a(razine napona). Kada se priključi punjač koji vraća napon iznad razine, zaštita se deaktivira. 5. Da, Li-ion / Li-Po su gotovo pa ista stvar, kao što i sam kažeš :slight_smile: 6. Li-Po i Li-ion se razlikuju interno, po korištenim materijalima.. tako da sve što mogu reći “tko zna” - vjerojatno i jesi u pravu.. :slight_smile: zapisao sam si ovo pa jednom provjerim i updejtam..

3

Customer:

That’s clear and concise, but a new question opened up for me.

If the load can always be connected, can the source also always be connected? The question might not make sense at first glance, but consider a situation where the load cannot be without power, so you would use this circuit as a UPS.

Power generally doesn’t go out for long periods so the battery would hold until it comes back, and combined with an INA219 I could implement a controlled shutdown if it really lasts too long.

Original message (Croatian)

Super, sve kratko i jasno, ali mi se otvorilo novo pitanje.
Ako trošilo smije biti uvijek priključeno, smije li biti uvijek priključen i izvor? Možda pitanje nema smisla na prvi pogled, ali uzmi situaciju da trošilo ne smije ostati bez napajanja, pa bi onda ovaj sklop koristio kao UPS.
Struja uglavnom ne nestaje na dugi period pa bi baterija držala dok ponovo ne dođe, a u kombinaciji s INA219 bi mogao napraviti kontrolirani shut down ako je stvarno dugo nema.

4

Soldered Support:

Yes, if the source is disconnected, the battery takes over powering. This isn’t designed to work as a UPS, but it will function. This is a very simple charger that isn’t packed with features, otherwise there are chargers that have options specifically for such things. The thing is called “PowerPath”, and it optimizes exactly these things - charging the battery and powering the system, ensuring the system is always powered, regardless of source or battery, and if there is “extra” energy - it charges the battery. We’re planning to design a board with such a solution.

Original message (Croatian)

Da, ako se isključi izvor, napajanje preuzima baterija. Nije to zamišljeno da radi kao UPS, ali funkcionirat će. Ovo je vrlo povoljan punjač koji baš nije natrpan mogućnostima, inače postoje punjači koji imaju opcije baš za takve stvari. Stvar se zove “PowerPath”, a optimizira baš ove stvari - punjenje baterije i napajanje sustava, osigurava da je sustav uvijek napajan, neovisno iz izvora ili iz baterije, a ako ima “viška” energije - puni bateriju. Dizajnirat ćemo pločicu s takvim jednim :slight_smile:

5

Customer:

I like this PowerPath concept. I’m thinking about systems with Croduino Nova, and then by definition a remote system is out of reach. Nova doesn’t have problems with sudden power loss but there are others that would be in the same environment with it. Using a UPS isn’t always the right solution for me because not all UPSes can give a signal “I have a little time left, shut everything down”. Those that can either cost too much or require some form of communication which again comes down to cost. This seems super elegant to me.

One question unrelated to this topic.

Can an ultrasonic sensor, for example HC-SR04, detect water? Of course, this is about a water kettle. Everything works great for me, but as testing goes on, I’m discovering new problems I didn’t predict, at least not to this extent. Namely, the water is so full of scale that the sensor I use would have to be taken out and wiped about once a month. And that’s much better than removing the entire mechanism, but I’m thinking if I could detect the water level with ultrasound, then I’ve solved that too. Then I really don’t have any more contact with water and scale.

Original message (Croatian)

Sviđa mi se ovo s PowerPath. Razmišljam o sustavima s Croduino Novom, a onda po definiciji udaljeni sustav nije nadohvat ruke. Nova nema problema s naglim gašenjem ali zato imaju drugi koji bi bili s njom u istom okruženju. Nije mi ni UPS ponekad pravo rješenje jer ne mogu svi UPSevi dati signal „ostalo mi je još malo vremena, daj sve pogasi“. Oni koji to mogu ili su preskupi ili zahtijevaju neki oblik komunikacije što se opet svodi na cijenu. Ovo mi se čini super elegantno.
Jedno pitanje nevezano za ovu temu.
Može li ultrazvučni senzor, npr. HC-SR04, detektirati vodu? Naravno, radi se o vodokotliću. Sve mi radi super, ali kako testiranje traje, otkrivam nove probleme koje nisam predvidio, barem ne u tolikoj mjeri. Naime, voda je toliko puna kamenca da senzor koji koristim bi trebao cca jednom mjesečno izvaditi i obrisati. I to je puno bolje nego vaditi cijeli mehanizam, ali si mislim ako bi ultrazvučno mogao detektirati razinu vode, onda sam i to riješio. Onda stvarno više nemam dodira s vodom i kamencem.

6

Soldered Support:

That’s it, if you’re really crazy enough to go read the application note: http://www.ti.com/lit/an/slua376/slua376.pdf

Yes it can. We measured the level of wax in some factory with this little and seemingly useless sensor a few years ago and it still works. Who would have thought!

Original message (Croatian)

To ti je ovo, ako si baš lud da ideš čitati application note.. :slight_smile: http://www.ti.com/lit/an/slua376/slua376.pdf

Da, može :slight_smile: mi smo mjeriti razinu voska u nekoj tvornici s tim malim i bezveznim senzorom prije nekih 5 godina i to još uvijek radi. Tko bi reko! :slight_smile:

7

Customer:

Thanks for this. I’ll redesign the water kettle for an ultrasonic sensor and see how it goes with it.

But I have a new detail related to a step-up converter. Just to remind you, I connected a single Li-Ion and a small PC fan, set it to 10V, and the voltage would jump to 20V and drop to 15V where it would stay.

Now I tried everything the same but the battery is not connected directly to the step-up but through the charger, which you don’t have in your offer anymore, but you have a replacement. That’s the one that has battery protection. And look at this, the voltage no longer goes wild. It’s exactly as I set it. I’ve been checking this for days now and it’s all good. Before, every startup would go to 20V. And the fan without a bulb. Earlier I tried the fan with a parallel bulb and it was okay, but those are two loads. Now it’s all fine if the battery goes through the charger. Interesting.

Truth is, I noticed the problem with inductive loads, but in this combination with the charger, even that’s not a problem anymore.

I don’t know how to explain it, but I read that article about how the step-up works and apparently if you put another inductor in the circuit, it disrupts the inductor in the converter. Probably some self-inductance. This shouldn’t happen, maybe it’s not that, but something’s happening. Whatever it is, it seems like the charger electronics somehow filter it. Doesn’t matter, the important thing is there’s a solution. For circuits with a single Li-Ion I would put in the charger anyway, both for protection and for easier handling. And now that I see it solves the problem with inductive loads, that’s it. I still need to test with relays and if it works with them, there’s probably a solution for 95% of cases. Relays and motors are probably the most commonly used elements.

Original message (Croatian)

[name removed] bok! Thanks za ovo. Preuredit ću vodokotlić za ultrazvučni senzor pa da vidim kako ide s tim. Nego, imam novi detalj vezan uz step-up konverter. Samo da te podsjetim, spojio sam jednu Li-Ion i mali PC ventilator, namjestio na 10V, a napon bi skočio na 20V i pao na 15V gdje bi i ostao. To je onaj koji ima zaštitu baterije. I gle čuda, napon više ne divlja. Onakav je kakav sam i namjestio. Već danima to provjeravam i sve 5. Prije bi svako ukapčanje išlo na 20V. I to ventilator bez žaruljice. Prije sam probao s ventilator paralelnom žaruljicom i bilo je ok, ali to su dva trošila. Sada je sve ok ako baterija ide preko punjača. Zanimljivo. Istina, problem sam primijetio sam s induktivnim trošilima, ali u ovoj kombinaciji s punjačem, ni to nije problem. Ne znam si to protumačiti, ali pročitao sam onaj članak kako radi step-up i očito ako se stavi još jedna zavojnica u krug, da ona poremeti radi one zavojnice u konverteru. Vjerojatno neka samoindukcija. To se ne bi trebalo događati, možda i nije to, ali nešto se događa. Što god to bilo, izgleda da elektronika punjača to nekako filtrira. Nema veze, bitno da postoji rješenje. Kod sklopova s jednom Li-Ion ja bi ionako stavio punjač, što zbog zaštite, što zbog jednostavnijeg rukovanja. A sad kad vidim da to rješava problem induktivnih trošila, to je onda to. Moram još probati s relejima i ako s njim radi, postoji rješenje valjda za 95% slučajeva. Releji i motorići su valjda najčešće korišteni elementi.

8

Soldered Support:

Do you have the version of the charger with protection, which means the battery goes through the protection?

Maybe it’s the MOSFET resistance through which the battery passes - if there are some peaks, because of the resistance they can’t happen so quickly, so the switcher can’t raise the voltage…? I have no idea, I’m just guessing. The important thing is the problem is solved, and thanks for the feedback - I’ll remember it!

Original message (Croatian)

imaš verziju punjača sa zaštitom, što znači da baterija ide preko zaštite?
Možda je stvar u otporu MOSFETa preko kojih ide baterija, ako postoje neki peak-ovi, zbog otpora se ne mogu dogoditi tako brzo, pa switcher ne može dići napon…? Nemam pojma, lupetam :slight_smile: bitno je da je problem riješen, a tebi hvala za povratne info - zapamtit ću!

9

Customer:

I’m not sure which battery protection you meant - over/under voltage, current strength or something else? That higher voltage appears on the step-up output, the input voltage, that is, the battery voltage is probably okay. In fact, by using the charger the thing improved slightly, meaning the number of situations when the voltage increases uncontrollably decreased.

But there’s one more detail I noticed. To the charger, that is, the battery via the charger I connected a bulb and discharged the battery to see if it would cut it off. The voltage dropped to 2.7V (I measured on the battery not on the bulb) and it didn’t cut it off. The bulb was still glowing which means the charger didn’t disconnect the battery from ground. I didn’t want to lower the voltage further. This measurement has nothing to do with the step-up module. In the circuit were only the charger, battery and bulb. I expected the charger to disconnect the battery and thus the bulb, but it didn’t. Fortunately, that problem doesn’t play a role for me with the water kettle because when the battery voltage drops to about 3V, the step-up module can’t boost it above 6V, so the solenoid valve doesn’t work and then I know I have to recharge the battery. But if instead of the valve it was electronics, that could create problems.

Original message (Croatian)

[name removed] bok!
Ne znam na koju zaštitu baterije si mislio, over/under voltage, jakost struje ili nešto drugo? Taj veći napon mi se javlja na step-up izlazu, napon ulaza, odnosno baterije je valjda ok. Dapače, korištenjem punjača stvar se malo popravila, odnosno smanjio se broj situacija kada se napon nekontrolirano poveća.
Nego, ima još jedan detalj koji sam uočio. Na punjač, odnosno bateriju preko punjača sam spojio žaruljicu i praznio bateriju da vidim hoće li je isključiti. Napon je pao na 2,7V (mjerio sam na bateriji ne na žaruljici) i nije isključio. Žaruljica je i dalje tinjala što znači da punjač nije bateriju skinuo s mase. Dalje nisam htio spuštati napon. Ovo mjerenje nema veze sa step-up modulom. U spoju su bili samo punjač, baterija i žaruljica. Očekivao sam da će punjač isključiti bateriju a time i žaruljicu, ali nije. Srećom, taj problem mi kod vodokotlića ne igra ulogu jer kad napon baterije padne na cca. 3V, step-up modul ne može dignuti na više od 6V, pa el. mag. ventil ne radi i onda znam da moram dopuniti bateriju. Ali da je umjesto ventila elektronika, to bi moglo stvarati probleme.

10

Soldered Support:

All the protections are “in-one”, in one chip, so I meant all of them together.

That’s actually fine. Look at the protection datasheet: https://cdn.sparkfun.com/assets/learn_tutorials/2/5/1/DW01-P_DataSheet_V10.pdf on the second page they write the voltages at which the protection activates - for undervoltage it’s 2.4V. When you get down to 2.4V, for the protection to reactivate again, the voltage must rise to 3.0V. For most batteries 2.4V will be fine and won’t leave permanent damage on it.

Original message (Croatian)

sve su te zaštite “in-one”, u jednom čipu, tako da sam mislio na sve njih zajedno.

To je zapravo u redu.. :slight_smile: pogledaj datasheeta zaštite: https://cdn.sparkfun.com/assets/learn_tutorials/2/5/1/DW01-P_DataSheet_V10.pdf
na drugoj stranici pišu naponi na kojima se zaštita aktivira - za undervoltage je to 2.4V. Kada odeš do 2.4V, da bi se zaštita opet reaktivirala, napon se mora popeti do 3.0V.
za većinu baterija 2.4V će biti u redu i neće ostaviti trajna oštećenja na njoj