EEVblog Electronics Community Forum

Products => Dodgy Technology => Topic started by: zarish2021 on June 01, 2021, 05:07:07 pm

Title: Lifetime Battery
Post by: zarish2021 on June 01, 2021, 05:07:07 pm
I want to know if the charging circuit here is successful

http://youtu.be/RRUBSWFemq8 (http://youtu.be/RRUBSWFemq8)
Title: Re: Lifetime Battery
Post by: tunk on June 01, 2021, 05:32:14 pm
From a quick view, it doesn't look like there's any
charging current limitation (unless the BMS has some).
And that battery won't last forever either.
It might help if you draw the schematics.
Title: Re: Lifetime Battery
Post by: Halcyon on June 01, 2021, 07:40:59 pm
Kind-of spam'ish, might be a bot. I've placed the OP on the watch list. If nothing else, moved to Dodgy Technology.
Title: Re: Lifetime Battery
Post by: Daixiwen on June 02, 2021, 06:35:26 am
Indeed, no current or voltage limit, this is definitely dodgy. He is using the protection circuit from a dead battery, so there is at least overvoltage protection, but this is not a charge circuit. The protection circuit is just supposed to be an extra protection in case of a failure of the charger voltage limiter. If the protection circuit itself ever fails (*) the polymer battery will directly receive 5V (minus the 0.6V from the diode) and will probably ignite.

USB chargers usually don't limit the current either and some can provide 2 amps or more. A 200mAh polymer battery won't survive long with such a treatment, but at least with such a high current the overvoltage protection will kick in pretty quickly.

Besides, how is this useful anyway? I don't remember the last time I had to change any battery in a remote but it has been years.

(*) the probability of the protection circuit failing is also higher in this case if charging with a higher current than designed for. They are usually protected against high current in the discharge path, but not in the charging path. Sending several amps through a small mosfet could destroy it and make it fail as a short, and then there would be no protection at all.
Title: Re: Lifetime Battery
Post by: Haenk on June 02, 2021, 07:42:29 am
Just use a bunch of regular low self discharge Eneloops or the like. They will last for a long time, are easily exchanged/recharged and certainly won't explode.

Just say no to stupid ideas.
Title: Re: Lifetime Battery
Post by: ebastler on June 02, 2021, 09:22:16 pm
I can easily see this battery lasting for the lifetime of the remote control. When the battery dies, it takes the remote control with it... :P
Title: Re: Lifetime Battery
Post by: agtrbt on June 11, 2021, 06:37:07 am
a good quality zinc carbon cell or CR2032 / CR123A will last a lifetime of the mother device.
Title: Re: Lifetime Battery
Post by: AVGresponding on June 11, 2021, 07:49:06 pm
a good quality zinc carbon cell or CR2032 / CR123A will last a lifetime of the mother device.

The manufacturers design lifetime..?
Title: Re: Lifetime Battery
Post by: agtrbt on June 13, 2021, 08:55:21 am
software wise, outdated protocols and firmware EEPROM wearout.

hardware wise, capacitor quality

I have overhauled a LG monitor with bad caps , gave it 8+ years more life.
Title: Re: Lifetime Battery
Post by: hexreader on June 20, 2021, 02:35:30 pm
Definitely a multi-forum, serial spammer  :'(