GEN 2 battery.. single blinking light.. wont charge past one light

I have now 2 very new gen2 batteries that are fast blinking a single light and wont charge past that point. Anyone else seeing this? Is there a fix or do I need to make a case for replacement.

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Do they stop charging at 25%, or is it the light indicator that’s broken? If they still charge to 100, but it only displays one dot, then something is up with the display.

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Gen 2 battery packs / life is new to most of us, I’d get on the phone with VEX Support ASAP and get them to help you. It will cut the wait time down and give you the best answer possible.


nope 25% is all im getting

If that’s the case, I’m not sure. I’m a V5 guy, I’mt not really sure what the case is with IQ batteries. I’d go with Foster’s advice, it’s probablly best to call VEX Support, and see if they either have a fix or if they can offer a replacement.

update… now one has moved past the single blinking to normal looking charging after putting it on a charger with more amps… the other just shut off like it was done charging… I check the status and it still says 25%… not a lot of documentation on these things… you can hold the little button down for a while and the 3rd light will light up… anyone know what that means… I’ll be calling support later today during planning

Each day, it feels more and more like vex manufactures their parts of cardboard and duct tape

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Are you using the vex cord to charge with?

we have two in my lab and they both sit at 25% as well, battery only lasts at 25% time

One of my new Gen two batteries had the one blinking light. I switched from my desktop USB port to my laptop USB port and left it plugged in when I was at work. It moved to two blinking lights. I put it on a usb charger overnight and it is back to four green LEDs.

We had similar issues as well. We eventually got it to start charging using a Nintendo Switch charger and now it seems ok.

It’s important to keep in mind that Li-Ion batteries like the Gen 2 batteries have a specific charge profile, which means you need to make sure you have an adequate charger.

When a Li-Ion battery is charging from a low capacity starting point, it spends the first 70-80% of the capacity in a “constant current” mode, which requires a lot more total power (because the voltage stays pretty constant throughout the charge cycle). If your charger does not allow enough current, then the chip in charge (hah!) of the charging cycle will typically prevent charging the battery. Graph from Google to help illustrate:

See how the blue line ramps up to a flat level? That’s the “constant current” mode. Once it hits a certain point, it then moves to the next phase, where it ramps the current down until it reaches capacity, but keeps the voltage constant.

I got to learn all about this like 16 years ago when I wrote the interface code to a battery charger IC in a still-fielded medical device. Kinda stuck with me. :slight_smile:

TL;DR - buy a charger rated for lots of power output and you won’t have a problem.

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