nPM1100-EK red LED lighting and a sealed battery

RE: nPM1100-EK red LED lighting and a sealed battery

Kazi Afroza Sultana — Thu, 02 Nov 2023 14:25:33 GMT

Hello Juan,

Unfortunately, its not possible to set the Ship mode in your condition when product is in a sealed condition.

You may think of using nPM1300; it can continue charging even the battery goes below 2.1V. This PMIPC also has the hibernation mode which is similar to the ship mode; except you can set a timer for it to wake in every 2ms to 3 days (in 2 ms steps).

Thanks.

Regards,

Kazi

RE: nPM1100-EK red LED lighting and a sealed battery

p143 — Wed, 01 Nov 2023 13:41:40 GMT

Hello Kazi.

I understand.

But the problem I have, as I mentioned before, is that in my Use Case, the battery and all the feeding electronics must be completely sealed inside the final product, so the user can´t set this Ship mode on, other than in the production phase. Is that right?

Thanks.

Best regards,

Juan

RE: nPM1100-EK red LED lighting and a sealed battery

Kazi Afroza Sultana — Wed, 01 Nov 2023 13:15:31 GMT

Hello Juan,

Here is the feedback from our team.

if battery voltage is below 2.1V nPM1100 will not charge it.

If the product is left unused for a long time, e.g. on the self before a customer buys it, it is recommended to use ship mode to reduce the current consumption (ref section 7.7 in nPM1100 product spec).

For most batteries they should last a long time in ship mode (460nA), and the battery self discharge is much higher.

RE: nPM1100-EK red LED lighting and a sealed battery

Kazi Afroza Sultana — Wed, 01 Nov 2023 12:12:15 GMT

Hello Juan,

The charger error mentioned in that sections can be solved by disconnecting and the reconnecting VBUS again.

''Could this VBATchargemin restriction be somehow avoided, or the battery fault detector be improved so the flaw mentioned above could be solved?'' In our latest PIMC (nPM1300), VBATCHARGEMIN is not even mentioned.
I am not entirely sure if this is the only reason for your case. I have asked developer and will come back to you shortly.

RE: nPM1100-EK red LED lighting and a sealed battery

p143 — Fri, 27 Oct 2023 14:36:24 GMT

Hello Kazi.

After thoroughly reading Nodic's nPM1100 Product Specifications document, I think I've found the reason behind the failure.
Being VBATchargemin 2.1v during charge,

and "Battery voltage lower than VBATchargemin after battery detection due to a fault with the battery" one of the reasons for the Charge Error Condition, it is obvious that the Charger Block is going to prevent Vbat from charging the battery after an extended time on the shelf.

Certainly, after let's say six months, of not being used and by natural discharge, any li-ion will get below 2.1v, meaning -if I'm not wrong- that your nPM1100 wouldn't be able to charge it again.

If this is the case (I hope not), in any Use Case in which the battery should be sealed inside the object to be fed, your PMIC wouldn't be compatible, and this, despite the battery being in perfect condition, as it is in my case, since I can charge the same battery seamlessly, with a conventional CC/CV wired power supply not having this VBATchargemin restriction.

My question is. Could this VBATchargemin restriction be somehow avoided, or the battery fault detector be improved so the flaw mentioned above could be solved?
Thanks.
Best regards,

Juan

RE: nPM1100-EK red LED lighting and a sealed battery

p143 — Tue, 24 Oct 2023 21:08:43 GMT

Hi Kazi.

Here I am, still waiting for your comments. Thanks.

Juan

RE: nPM1100-EK red LED lighting and a sealed battery

p143 — Fri, 20 Oct 2023 20:37:57 GMT

Hello Kazi.

You can be sure that VBUS input voltage is within the recommended operating conditions, that is, between 4,1v and 6,7v.
The problem occurs when VBAT is below more or less 1,8v (by natural discharge). Then, if I try to recharge the battery by feeding VBUS with 5v (monitored and OK) from the Wireless Power Supply and using the VOUTB 1,8v output, the red LED goes on, and the operation gets cancelled.
The funny thing is that if I charge the same battery with a conventional wired Power Supply (5v. CC/CV), the problem does not happen.
(I've tried two nPM1100-EK boards with identical results).
Any other suggestions?
Thanks.

Best regards,

Juan

(By the way. VOUTB, despite the red LED affair, was working in both cases. Feeding with the wireless power supply and through the USB connector)

RE: nPM1100-EK red LED lighting and a sealed battery

Kazi Afroza Sultana — Fri, 20 Oct 2023 11:40:47 GMT

Hello Juan,

You are welcome.

You are sure that both voltage of VBUS and VBAT did not go below the minimum range?

Brown Out Reset (BOR) occurs if both supply voltages /VBAT and VBUS)are below the minimum of the parameter range. The device is held in reset, or System OFF, when both supply voltages VBAT and VBUS are below minimum thresholds.

The battery monitoring circuit allows the battery voltage to be sampled by the nRF5x ADC. The transistors enable battery voltage sensing through a resistive divider. When not sampling, the transistors prevent current leakage to ground. The circuit is designed to ensure the voltage range on an analog input pin over the battery voltage is within the limits required by the nRF5x GPIO and ADC. A battery voltage of 2.8 V to 4.2 V is scaled down to 360 mV to 540 mV at P0.xx for sampling. If software on nRF5x determines that the battery on nPM1100 is low, the Low Bat LED can be switched on via GPIO. This circuit sources the LED current from VSYS. VSYS will not be supplied after VBAT drops below VBATBOR because CHARGER will isolate the battery when a brownout reset occurs.

RE: nPM1100-EK red LED lighting and a sealed battery

p143 — Thu, 19 Oct 2023 15:05:26 GMT

Hi Kazi.

Of course, in my circuit, the Vbus>Vbat condition is always met since an LDO precedes your nPM1100 with a 5 volts regulated output, whose input is constantly monitored to be between 4,5 and 45 volts.

In my opinion, the problem arises when Vbat, due to natural auto-discharge, goes below Vbat <2.30V (which, according to your nPM1100-EK User Guide, is the minimum battery operating input range). Then, apparently, and being the battery in perfect condition, you can`t recharge it anymore using an nPM1100 EK PMIC. The ERR LED goes ON and prevents the battery from charging.
Thanks for your suggestions.
Best regards.

Juan

RE: nPM1100-EK red LED lighting and a sealed battery

Kazi Afroza Sultana — Fri, 13 Oct 2023 04:57:17 GMT

Hello,

Can you please check the VBUS voltage? If the VBUS voltage goes below VBAT, battery can not be charged.

Thanks.

Kazi