From: Jim Ruxton <jim.ruxton@gmail.com>
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Date: Thu, 3 Sep 2020 19:25:42 -0700
Subject: Re: [OT] Simple LiPo charging circuit
Thread-Topic: [OT] Simple LiPo charging circuit
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Thanks James and Russel for the posts. I hadn't considered that the=20
battery may have some integrated circuitry. There are no markings on the=20
battery so it's hard to know without dissecting it. I have ordered some=20
TP4056 modules so I'll give that a try when I replace the 180 mAH=20
nattery with a larger one. I greatly appreciate the advice.

Cheers,

Jim

>
> That is a good way to destroy the battery early or very early or very ver=
y
> early.
>
> I'll add this here after writing the material below first :-).
>
> An easy way to get a good result is to but a TP4056 module from
> ebay/AliExpress/... .
> These cost close enough to $0 to be hard to beat.
> You can get ones with and without low battery cutoff. The with-cutoff
> ones are a very good idea.
> Distinguishable by some extra hardware and 4 output pads - Vout + - and
> Battery + -
> You get CCCV charging, CC rate settable and low battery discharge termina=
te.
>
> They seem to have got even cheaper than when I last bought some.
> This page has both types as above - plus it seems mini/micro/type C USB
> power input connectors.
> Example only - not a recommendation - but seems as good as most. YMMV.
>
> https://www.aliexpress.com/item/4000061318186.html?
>
> They also offer a version with a switchmode converter allowing a higher V=
in
> (typically up to about 18V rather than the 6V or so for TP4056)
>
>
> ________________________
>
> Simple methods are used "because they can".
> The cell MAY have an internal BMS to sort-of protect it.
> MAy.
> ________________________
>
> LiPo / LiIon should be charged by CC to Vmax with *immediate* terminate,
> or, more usually, CCCV with CC to Vmax, and CV to some CC/N value. N=3D2 =
2 is
> a good charge, n=3D4 is heavyish and N=3D10 is "road warrior".
>
> CC only at mA =3D cell_mAh with immediate terminate at Vmax gives 89-90% =
of
> max capacity and
> CC at mA =3D mAh_cell/2 gives 90%+ of max capacity.
> Immediate terminate at V=3DVmax gives significant gain in cycle life and
> whole of life mAh.
>
> Lowering Vmax slightly gives significant increase in cycle life  and whol=
e
> of life mAh.
>
> FWIW - nobody wants to do it - setting Vmax to about 3.85V (from memory)
> allows Mars Rovers to get about 8000 cycles with LiIon. Capacity (from
> memory) is about 50% of max.
>
>
> Russell
>
>
>
>
>>
>>
--=20
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