Batteries getting weak: How do you know?

[zadiac]

So I was wondering. I'm still on my first set of batteries. How do you know it's time to replace them, as in completely?

Do the batteries not hold the charge for long anymore?
Do they run down quicker? or
Do they not charge up to 4.2v anymore?

I haven't had any batteries that did one of the above or fail completely so far. So I don't know what to expect.

Veterans please advise.

Thanks.

 

[johan]

So I was wondering. I'm still on my first set of batteries. How do you know it's time to replace them, as in completely?

Do the batteries not hold the charge for long anymore?
Do they run down quicker? or
Do they not charge up to 4.2v anymore?

I haven't had any batteries that did one of the above or fail completely so far. So I don't know what to expect.

Veterans please advise.

Thanks.

These batteries have on average a charge-/discharge cycle of around 500+. The first sign will be a quick loss of charge; ie. fully charged to 4.2V and within 12 hours self discharge to <4.1V. The next sign will be maximum charge voltage - when they don't want to charge >4.1V. When any of these 2 situations occur, they will also discharge way quicker during operation and even become warm.

All this happens gradually under normal operating conditions and are difficult to predict. Some cheap-n-nasty-made-in-a-hell-of-a-hurry-in-china batteries, normally just suddenly fail (either don't charge and/or don't hold any charge).

 

[zadiac]

Thanks Ohm Johan. I will look out for those symptoms.