Troubleshooting LiPo Shim


I’ve got a LiPo Shim that is not working with a 3.7V 1400Mah lipo battery (Nimo brand) from the electronics store.

I’ve charged the battery with Adafruit’s Micro-usb Lipo charger and I get 3.53v (a bit low, no?) with a multimeter after getting “charged” indication’s green light.

A led lights up connected directly to the jst connector.

What can I test further, before getting another battery?

3.53v does seem to be too low to me. It should be around 4v fully charged. The LIPO shim has a low battery voltage LED, does that light up? If it does, the upconverter will not turn on and you won’t get your 5v out of it.
I see this mentioned on the Adafruit product page for that charger,
“For charging single Lithium Ion/Lithium Polymer 3.7/4.2v batteries (not for older 3.6/4.1v cells)”
I didn’t know there were two different batteries? Make sure yours id the 3.7 /4.2 V one. You may have to google the part number, or go to the manufacturers page.
The other thing to double check is that the polarity of the JST plug on the battery is the correct polarity.

Nothing lights up on the LiPo Shim.

My battery does display 3.7v on the side.

Thanks for the polarity check tip, will try it later today.

I’m guessing this battery, even though it is a branded one, is poor quality.

This store has a tradition of using cheap imports.

I would order everything from Pimoroni but I always have a really tight budget and 28€ posting for 1 or 2 batteries is really hard to justify.

Is that the only LIPO battery you have? I’m leaning towards it being the battery.

I’m afraid it is the only one.

Shouldn’t it light anything on the LiPo Shim, though?

I mean, since it lights a led and outputs at least the 3.53v…

How good, quality wise, is your voltmeter?
According to the LIPO Shim product page you should see the low battery indication at or below 3.4 V, and an auto shutdown at 3.0 V. If your meter is reading high that might explain why it doesn’t turn on.
Also have you checked the polarity of the wires on the battery? The Red wire should be connecting to the terminal with the + and the black to the - on the LIPO shim JST connector. The LIPO shim may be reverse voltage protected.
With the battery plugged in you should be able to measure its voltage on the Bat+ and Gnd contacts on the LIPO Shim.

Thanks @alphanumeric

Ok, just checked the polarity and it’s ok.

Also tested the battery with the Wide Input Shim and it powers a zero w.

I’m guessing the battery is rubbish…

Will have to wait for a couple of months until I have the budget to get lipos from pimoroni (since I’m living in the south european desert where it’s impossible to go to a shop and purchase high quality batteries) :/

Would you think it is worth it to purchase another Nimo li-po (or li-on) battery (maybe with different Mah) or is it more likely that they’re just made to lower standards?

If the battery works with the wide input shim, thats suggests that the LIPO Shim “may” be bad. To me it does anyway. You don’t get any of its LED’s to light up. I would think that at the very minimum the Low Battery indicator should light up?

Thank you, @alphanumeric

I’ll put the question to support as it will be a while until I could test the lipo shim with pimoroni batteries.

If you go to the Shop page, there is a “contact us” link at the bottom of the page. Click that to e-mail tech support directly and put a link to this thread in the e-mail. That should get you a quick reply. ;)

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I’ve made further tests and can now confirm that LiPo Shim is ok, the battery is also ok but the polarity check that I’ve made before was stupid (I’ve only checked red for positive and not also orientation of JST connector).

I now have low voltage (blue led) warning on LiPo Shim and a powered up zero w.

The wrong polarity on battery JST terminal means I fried my Adafruit micro-usb lipo charger :)

Everyone, check the polarity/orientation of the JST terminal for your batteries! :)

The successful power-on of a zero w with the Wide Input Shim was possible because I by-passed the JST orientation.

Thank you so much @alphanumeric!

I probably could have been clearer in what I wanted you to check. Yeah, some of the cheaper batteries may have the red and black wires transposed / backwards in the JST plug. I think Adafruit actually puts a disclaimer to that effect on some of their product pages. A warning to double check it if you don’t buy your battery from them.
That may not have been all that good for the battery either? You won’t know until you get another charger and see if it actually charges to full capacity.

Not at all, your help was extensive and to the point!

Thank you for the caution regarding the battery!

Sincere thanks, Kerry!

And a thank you right back at you. =) Hopefully the battery is OK.