LiPo Charger/Booster charging function not working

Components & Accessories Power
1

Hello! We have been having ongoing issues with a setup that was recommended to us a few months ago. Very basic, with a WAV player, a LiPo Booster, recommended 3.7v battery, speaker, and and a reed switch interrupting the power to the WAV board (with a jumper on Trigger 1)

The setups worked for a while, but then we realized the batteries were not charging. The LEDs on the LiPo Boosters were indicating that they were charging properly but no power was going to the batteries when a voltmeter was used. When we used a LiPo Basic, or disconnected totally from the WAV player, the battery would charge.

After doing some more digging, i read about the amperage limitations for charging a battery while a load is connected. I am now trying to use the EN pins and EXT SW pins on the Booster/charger to make it so that I can charge the battery when it dies, and turn the WAV player on and off with one switch (we designed the objects off the original recommendation which did not include using the EXT SW or EN pins) - if at all possible, we need to figure out how to resolve this without adding an additional switch. Below is the results of my tests where I’ve transferred the switch from its original place (interrupting the power) to the EXT SW- neither with good results.

EN - jumped to ground

EXT SW - reed switch (no effect on WAV player)

charges (voltmeter reading on battery when connected to charger 3.25, increasing), but does not power board

EN- not jumped

EXT SW- reed switch (successfully activating/deactivating wav player)

powers board, does not charge (voltmeter reading on battery when connected to charger .15v, unchanging)

To clarify, I have 5 of these systems. I set up one external to the objects the others are encased in so that I can quickly and easily check for continuity, as well as swap out the components to the other systems to narrow down the possible issues. My connections are solid, the WAV players are functioning, and the switches seem to work interchangeably as well. I am certain it’s the LiPo booster unit (or the way I am using it)

any advice would be greatly appreciated! I’m having trouble uploading images, so I apologize for the lack of visual representation.

2

Hello JS_Studio20,

EN Jumped To Ground, Charging, WAV OFF

The behavior you see with this configuration is correct. When you pull EN to ground, the BOOST IC’s output is disabled.

EN floating, No Charging, WAV ON

The maximum current load that the charger will handle while charging is roughly 10mA. The WAV Trigger is most likely pulling more than this while it is not in use.

I’m not aware of how to kick the WAV Trigger into a sleep mode, and furthermore if that sleep mode will draw <10mA. An external switch will most likely be needed.

I hope this helps.

3

Dear Brandon,

Thank you so much for the response and for confirming that the behavior I’m observing with the booster is not indicative of a defective booster. However, the issue isn’t resolved. So, you’re saying even when the power to the WAV player is interrupted, it still draws >10mA? Adding a switch to the load was the original recommendation from the sparkfun rep that sold us the units, so I’m unsure why the system was recommended to us if it can’t work.

As to adding an external switch, you can see in my original post I’m trying out using the EXT SW instead of interrupting the load. According to the hookup guide, this supposedly puts the piece in “standby mode” - does this also draw amperage, disabling the charger? I’ve also tried controlling the EN pin - do you think this could work with a reed switch?

This seems like a very simple function for the product- adding an on/off switch that allows charging when it is off. If this is not possible, I’m confused why we were led to believe it is. How do most people utilize the product? By totally disconnecting the booster from the load to charge the battery every time? If so, this should have been made prominent in the item description/hookup guide, which states the LiPo booster is “perfect for projects that need to be mobile and not rely on an external charger”

Either this is untrue, or there is a way to utilize it as advertised. Please advise us how to create a charging option with a switch that controls the power supplied to the board, and where the best place to put the switch would be?

Thank you so much for helping and for your time!

4

Brandon, boosting this with a direct reply in hopes you’ll be able to see my questions above. Thank you so much!

TS-Brandon:
Hello JS_Studio20,

EN Jumped To Ground, Charging, WAV OFF

The behavior you see with this configuration is correct. When you pull EN to ground, the BOOST IC’s output is disabled.

EN floating, No Charging, WAV ON

The maximum current load that the charger will handle while charging is roughly 10mA. The WAV Trigger is most likely pulling more than this while it is not in use.

I’m not aware of how to kick the WAV Trigger into a sleep mode, and furthermore if that sleep mode will draw <10mA. An external switch will most likely be needed.

I hope this helps.

5

JS_Studio20:
So, you’re saying even when the power to the WAV player is interrupted, it still draws >10mA?

That depends if the unit is physically disconnected from the LiPo battery/charger. If they're still connected but the WAV trigger is kicked into standby, then it could draw >10mA if that's how that board behaves in standby. I don't have that standby information on hand.

Is your WAV trigger being powered by a completely separate source than the LiPo battery/charger?

JS_Studio20:
Adding a switch to the load was the original recommendation

Are you adding a switch on the EXT SW pins or in series with the OUT pins to the WAV board?

JS_Studio20:
this supposedly puts the piece in “standby mode”

I believe that it's not the EXT SW pins, but the EN pin. We can try placing a switch between the EN pin and Ground.

The EXT SW pins just allows you to ‘replace’ the battery switch so you can have a switch wired but not physically on the board.

6

TS-Brandon:

JS_Studio20:
So, you’re saying even when the power to the WAV player is interrupted, it still draws >10mA?

That depends if the unit is physically disconnected from the LiPo battery/charger. If they're still connected but the WAV trigger is kicked into standby, then it could draw >10mA if that's how that board behaves in standby. I don't have that standby information on hand.

Is your WAV trigger being powered by a completely separate source than the LiPo battery/charger?

No, it is being powered from the Lipo booster via the output pins. This was also where we were originally interrupting the power (a reed switch placed between the output pins and the WAV trigger)

TS-Brandon:

JS_Studio20:
Adding a switch to the load was the original recommendation

Are you adding a switch on the EXT SW pins or in series with the OUT pins to the WAV board?

JS_Studio20:
this supposedly puts the piece in “standby mode”

I believe that it's not the EXT SW pins, but the EN pin. We can try placing a switch between the EN pin and Ground.

The EXT SW pins just allows you to ‘replace’ the battery switch so you can have a switch wired but not physically on the board.

The switch was originally in series to the OUT pins on the WAV board. Last time I tried this, when I was trying everything i could think of, it seems like it did not recognize the switch, so i didn’t pursue it further. It is possible, however, that I did not think to switch the on board booster switch back to “on”- I can’t remember. So, I’ll try this again. I’ll let you know what happens when I try a second time tomorrow morning. Let me know if you are able to find out anything else.

I really appreciate this assistance. Thank you!

7

Sorry, I meant-

The switch was originally in series to the OUT pins on the WAV board. Last time I tried to put a switch on the EN pins, when I was trying everything i could think of, it seems like it did not recognize the switch, so i didn’t pursue it further. It is possible, however, that I did not think to switch the on board booster switch back to “on”- I can’t remember. So, I’ll try this again. I’ll let you know what happens when I try a second time tomorrow morning. Let me know if you are able to find out anything else.

I really appreciate this assistance. Thank you!

8

I seem to have this exact same problem, the battery is not charging and the blue led stays on for ever. I wonder if your search came up with a solution? I do have a switch on the boosters Ext SW pins. Advice is very much appreciated!

9

Hello jaap.

  • - What battery do you have attached to the board?

  • - Is the on board switch in the on or off position when you're trying to charge the battery?
  • - Is your load disconnected from the board when you're charging the battery?
  • - Can you post photos of the top and bottom of your board and a photo showing the battery attached?
    • 10

    Battery is a 2000mAh 3.7 V (LP803060)

    Onboard switch is off

    The load is not disconnected, but I supposedly disconnect through the external switch

    When I physically disconnect = unplug the wires from the mp3 board, the battery seems to charge. This took about 7 hours to fully charge (blue led went to off). The red led stayed on all the time, is that normal?

    My question is, how to fully disconnect the load when charging? Could I wire the voltage that goes out (from the board to the mp3) through the external switch as well? That would disconnect it. But than, when the switch goes to on, also the current would go through that switch.

    A quick and clear solution is what I hope for.

    IMG_1690.jpg
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    IMG_1691 2.jpg
    IMG_1691 2.jpg3024×4032 3.43 MB

    11

    In addition to what I wrote and to clarify my suggestion: in this thread is a mentioning/question “Are you adding a switch on the EXT SW pins or in series with the OUT pins to the WAV board?”

    Is this what I should do?

    Thank you for your assistance.

    12

    Thanks for sending those photos, they do help! :slight_smile:

    All the on board or external switch (if installed) does is disconnect the battery from the board. It’s the same as unplugging the battery. If you try to charge the battery with the switch open, (off) it will never charge because it’s not connected.

    Looks like you have a 2000mAh battery, the board charges the battery at 500mA, BUT if you have the boost circuit enabled, that’s going to consume some of that 500mA and it won’t go into the battery. With the booster off and no load attached, it should take 4-5 hours to recharge your battery, maybe a bit less if the battery isn’t totally drained. With the boost circuit on, it will take longer and if you have a load attached that’s drawing 500mA or more from the battery the battery will never fully charge.

    If you want to charge the battery as quick as possible, make sure the switch (on board or external) is turned on, the boost circuit is disabled, (see the [hookup guide, specifically the section that discusses the EN pin) and you have the board connected to a power source that’s capable of providing 5 volts at 550mA or more.](https://learn.sparkfun.com/tutorials/sparkfun-5v1a-lipo-chargerbooster-hookup-guide)

    13

    Thank you for clarifying this. I hoped to do everything with one switch, but please correct me if I am wrong; it seems I need a three-position switch:

    • position 1 to disconnect the battery (connected to the ext sw pins)

    • position 2 to connect the battery + disable the charger (e-pin) + disconnect the load

    • position 3 to connect the battery + enable the charger + connect the load

    Thank you again for you assistance, it is really helpful!

    14

    If you want a way to disconnect the battery and disable the load for charging, it’s best done with 2 switches.

    One switch to disconnect the battery. This shuts everything down. (no power to your load, no battery charging)

    The other switch connected between GND and EN. This shuts off the boost circuit effectively shutting off your load. There’s no need to actually disconnect the load if the boot converter is shut down, if the boot converter isn’t running there’s no power going to the load. When the battery is disconnected, it really doesn’t matter what you do with the EN pin since there’s no power available to run your load anyway.

    I’d recommend keeping your switch for disconnecting the battery and only using that when (if) you need it. Then connect the other switch up to the EN pin to shut off the load when you need to charge the battery.

    **If you need to charge the battery:**
  • - Keep the battery switch ON
  • - Turn the EN switch OFF

    • For normal operation:

  • - Turn the battery switch ON

  • - Use the EN switch to turn the load ON or OFF as you needed.

    • If you need to shut things completely off or put the assembly into storage:

  • - Turn the battery switch OFF

    • 15

    Thank you so much! This will do.