FP3: how to charge battery without phone

Fairphone could manufacture a battery charger for their phones, but few people need them. Those who need more charge just get a battery bank.

sorry, but one things that made me opt for FP is that I do not need a battery banck, because I can swap my battery any time.
I understand that just few people need a charger (I’m one of this)

Hi Renato,

still wondering: what exactly is your need? Do you regularly spend longer periods of time without access to a power outlet?

Best wishes,
Thomas

No, what I want is to use my own two battery and let them to last the more possible. To do so, I discharge the battery, before to insert the second one. So I would need a charger that is not the phone

Renato

As far as I know, it is not necessary at all to completely discharge a modern battery. Especially not if you want to preserve it or use it as long as possible.

Lithium-ions really hate a deep depth of discharge. According to Battery University, a staggeringly exhaustive resource on the topic, a li-ion that goes through 100 percent DoD (the user runs it down all the way to zero before recharging) can degrade to 70 percent of its original capacity in 300-500 cycles. With a DoD of 25 percent, where the user plugs it in as soon as it gets to 75 percent remain, that same battery could be charged up to 2,500 times before it starts to seriously degrade.

Quoted from:

How to Keep Your Phone’s Battery Healthy (popularmechanics.com)

Best wishes,
Thomas

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:flushed:All that I knew…until now…isn’ t true…

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Yep. I’m not an expert so I will quote someone who is:

No, it is not OK to have a Li-Ion deeply discharged at all.

Here is why: When discharged below its safe low voltage (exact number different between manufacturers) some of the copper in the anode copper current collector (a part of the battery) can dissolve into the electrolyte. The copper ions (atoms?) then in turn can stick on to the anode during charging by chemical reduction and cause dendrites. The dendrites might cause a short circuit inside the battery. So basically discharging too much is as bad as charging too much. But the dendrites caused by overcharging is formed out of lithium.

Normally the battery pack should have some sort of supervisory circuit that disconnects the cells from the charger or load when the cells are above or below the recommended voltages.

Question 2:

Does a deeply discharged battery have higher or lower self-discharge compared to normally charged battery?

A deeply discharged battery might have a higher self-discharge due to the above mentioned damage.

From what I can see in the data sheet provided by a large manufacturer (under NDA) the best relative (%) capacity retained is at somewhere around 50% charge and at low storage temperature.

Once I get home from work I get roughly 50% battery left anyway, so from what I’ve learned I would aim at that.

@Renato
Could you not just re-insert the discharged battery at night when the phone is not being used to recharge it for example.

And as far as charging and discharging Li-ion batteries will last a lot longer the less discharged they are and not overcharged, so a max of 90% charge would be better. If the phone reaches 90% and charging slowly then it is fine to stop charging.

The inbuilt charger no doubt has a monitor to stop too much discharge and overcharge but consumers like to have a long battery life so the parameters are not designed for long battery life but long daily use.

Unlike lead acid batteries which can take 20% to 30% overchange (as long as they don’t get hot) li-ion can not cope with heat so the lower the charge voltage the better. Once the battery reaches 4.2v it is at the top range of use more than that and yes the battery will last a lot longer per day but have a shorter overall life.
https://www.eetimes.com/current-voltage-and-temperature-govern-li-ion-battery-charging/#

:disappointed:

Oh…it’s really too much for me…
What I understood is that:
1 - maybe it was better not to buy the second battery
2 - just don’t even look for the charger and plug it in every moment that the battery is under 50%.

… “you never stop learning…”

Thank you

Renato

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A second battery is a great idea. Once it’s charged use once if every month to ensure it is fine. You never know when you may be without a charger and can carry a spare battery. :slight_smile:

Yes looking for a separate charger is a bit unnecessary.

A separate charger is a perfectly fine thing to have.
What if the phone doesn’t charge the battery any more because of a problem? You’ll still be able to charge.

Yes a separate charger could be useful and is more in line with the title of this topic, not how important having one is. It is so easy to go off at a tangent :flushed:

yes…but with one?
FP have “strange” battery
not all universal charger works

Renato

Maybe you could get a recycled FP case with just the charging module or build yourself a charger.

The link below gives you the idea but you will have to ensure you know which connections on the battery to use.

I really don’t know what to do here anymore.
I linked to an earlier post of mine where I specifically pointed out to look out for the contacts of the charger because they needed to be thin enough … and I linked to working chargers two times.
Should I just change .de to .it in the eBay links? Ok, still available …

https://www.ebay.it/itm/264715241517

https://www.ebay.it/itm/401760527578

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And of course https://www.ebay.co.uk/itm/401760527578

Doesn’t look too shabby :slight_smile:

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?? @Renato_Pontefice

Looks a bit confusing to me but this post said you had a charger weeks ago on 4th Nov ??

yes, I had one from 4th November, but it doesn’t works.
Then I had a second (and it doesn’t works too)
I understood the I need a different charger and [AnotherElk] show me a link.
then another one wrote me another link.
Finally I’ve bought that AnoterElk told me in e-bay
but I putted 2 article in the basket so I can’t check-it out before remove one article, but to do that I had to write to seller and tell him to left one article from my basket, but the site was written in German (which I do not know)
So I had to contact e.bay customer support to tell me how to remove an item.
Today (almost a month later) I finally ordered the charger, which should arrive in 10/15 days.

Get the story?

Thank you all and I hope this is the right time

Renato

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