Author Topic: USB lithium battery stops charging before it's full  (Read 262 times)

USB lithium battery stops charging before it's full
« on: 21 November, 2021, 12:03:57 pm »
My USB rechargable front light doesn't seem to charge properly.

It's got a four bar charge indicator. If the light shows one bar in red (nearly flat and needs charging) and I start to charge, straight away it's at 2 bars charged, after about 10 minutes it's showing charged at 3 bars.

When it stops charging, the battery is only about 75% charged but all four bars show as full. I can get it more charged but I have to disconnect and reconnect the cable. I have to do this several times as each time it quickly stops charging.

Is there anything I can do about it?

Oh it fell off my bike once and smashed into the ground, hard enough to break the lens, I'm not sure if that's affected the charging.

Wombat

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Re: USB lithium battery stops charging before it's full
« Reply #1 on: 21 November, 2021, 12:21:35 pm »
How many charge cycles do you reckon its been through?  Could it be knackered?
Wombat

Re: USB lithium battery stops charging before it's full
« Reply #2 on: 21 November, 2021, 12:30:13 pm »
I think less than 100.

Re: USB lithium battery stops charging before it's full
« Reply #3 on: 21 November, 2021, 03:02:29 pm »
Buy an new light.  One that has replaceable batteries.  Recharge the batteries in a good quality recharger.  Have two sets of batteries at least so that there is always one set in the charger and one set in the light.

jiberjaber

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Re: USB lithium battery stops charging before it's full
« Reply #4 on: 21 November, 2021, 03:24:36 pm »
My USB rechargable front light doesn't seem to charge properly.

It's got a four bar charge indicator. If the light shows one bar in red (nearly flat and needs charging) and I start to charge, straight away it's at 2 bars charged, after about 10 minutes it's showing charged at 3 bars.

When it stops charging, the battery is only about 75% charged but all four bars show as full. I can get it more charged but I have to disconnect and reconnect the cable. I have to do this several times as each time it quickly stops charging.

Is there anything I can do about it?

Oh it fell off my bike once and smashed into the ground, hard enough to break the lens, I'm not sure if that's affected the charging.

Sounds like it's getting a bit worn out, it's probably hitting its charged state but the capacity is declining. If the manufacturer has skimped on the C rating of the internal battery to save costs compared to the actual lamps current requirements then this will shorten the cycles you can get the most charge out of it for...

Alternative is that it might be sensing a temperature drop (charging in a cold room?) and reducing the charging accordingly.

What light it is?, might be able to replace the internal battery(s)
Regards,

Joergen

Re: USB lithium battery stops charging before it's full
« Reply #5 on: 21 November, 2021, 03:54:12 pm »
How are you determining it’s only 75% charged?

Battery indicators are often nonsense.

Re: USB lithium battery stops charging before it's full
« Reply #6 on: 21 November, 2021, 04:17:55 pm »
It's a Lidl Crivet light with a dynamo like shaped beam (horizontal cut off). I do actually have an older version of the light that takes 4 AA batteries and also a B&M Ixon IQ Premium (also 4xAA).

I think it's only charging to 75% because a few weeks ago I tested it and got about 2 hours running time whereas it ususally goes flat at 1 and a half hours, although I could have made a mistake.

Anyhow, I'm not too bothered about this, I have to charge it before each evening commute anyway.