# Battery flashes red after startup

**URL:** <https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143>\
**Category:** Trouble shooting\
**Created:** [September 4, 2025, 8:34pm UTC](https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143 "2025-09-04T20:34:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![haraldthi](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@haraldthi](https://infinite-battery.discourse.group/u/haraldthi)\
**Post date:** [September 4, 2025, 8:34pm UTC](https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143/1 "2025-09-04T20:34:14Z")

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Hi. I have a battery I have charged to full then depleted almost entirely. I then left it in a trailer, replacing it with other batteries I have until the trip was over. After coming home, I left it for a day or two before trying to recharge, and to my dismay it goes flashing red. The battery activates with four white light, then starts flashing four red lights.  
I can connect to it with the app through Bluetooth, and the battery seems to have charged just fine. The cells look good in the app, and even the “Error State” says “OK”. (See the attached picture.) Yet I can’t get rid of the four flashing lights. So what can the problem be, and how can I fix it?

 ![Screenshot_20250904-221636](https://canada1.discourse-cdn.com/flex028/uploads/infinite_battery/original/1X/2af2cedb50b5869356aae88fbeb43f834582a378.png)

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**Author:** ![Alex](https://avatars.discourse-cdn.com/v4/letter/a/db5fbb/32.png) [@Alex](https://infinite-battery.discourse.group/u/Alex)\
**Post date:** [September 22, 2025, 1:33pm UTC](https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143/2 "2025-09-22T13:33:45Z")

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Hello Harald,

sorry for the late reply.

The red light blinking means that the battery was in alert. The alert was due to the fact that you had more than 70% humidity inside the battery.

 ![Screenshot 2025-09-22 at 15.32.09](https://canada1.discourse-cdn.com/flex028/uploads/infinite_battery/original/1X/96e2532a8300020501db99d192c2a42217272770.png)

I have removed the alert as now the humidity level is back to normal.

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**Author:** ![haraldthi](https://avatars.discourse-cdn.com/v4/letter/h/e9c0ed/32.png) [@haraldthi](https://infinite-battery.discourse.group/u/haraldthi)\
**Post date:** [September 26, 2025, 8:20am UTC](https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143/3 "2025-09-26T08:20:31Z")

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Thanks for fixing it, though. It’s interesting to see how much you can work with these batteries. Perhaps these things could be included in the app, over time? I’m not sure how much use we can have for it but with some text warnings then perhaps.  
But the battery isn’t fully waterproof? Is it the venting seal? That last day of the trip was _wet_, and my trailer isn’t all tight. So I’ll have to pack my batteries in a waterproof bag as well, then, like the rest of my luggage.  
Good to know.

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**Author:** ![Alex](https://avatars.discourse-cdn.com/v4/letter/a/db5fbb/32.png) [@Alex](https://infinite-battery.discourse.group/u/Alex)\
**Post date:** [October 3, 2025, 3:47am UTC](https://infinite-battery.discourse.group/t/battery-flashes-red-after-startup/143/4 "2025-10-03T03:47:22Z")

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the battery is really waterproof in itself (IP67) and we have batteries that spent a few days in rivers that are working like charms.

70% of humidity inside the battery is quite low (you should not even see a drop if there is no condensation).

two things can explain water insinde the casing:

1. you assembled your battery in a humid environment (doesn’t look to be you case)

2. you have a very small ingress that can come from a malpositionned seal, a bad bottom connector waterproofing of from a top casing that is not tight enough (sometimes the anderson discharge connector can force on the top part of the casing if they are malpositioned). We have fixed this in latest prodcutions.