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Electronics => Beginners => Topic started by: simondid on June 21, 2016, 06:12:05 pm

Title: lipo loadsharing circuit fit my needs / scourcing issues
Post by: simondid on June 21, 2016, 06:12:05 pm
Hey

so i’m traying to find a lipo charing / loadsharing circuit that fit’s my needs

My circuit is going to draw around 300-400ma at peak normal / low power mode witch it is going to be for most off the time. Shut end op around 10-50ma.

I’m aming to have around 3-6 18650 lipo battery  http://www.ebay.com/itm/201468564314 (http://www.ebay.com/itm/201468564314) in parallel and a setup converter to supply the 5v need
 
I found this adafruit bord https://www.adafruit.com/products/2465 (https://www.adafruit.com/products/2465) witch seems to fit my needs but I’m having trouble scouring it in my country… plus the price is kind of high.

 So I’m looking for a new circuit bord that fit the same needs I blog post describing a load sharing circuit http://blog.zakkemble.co.uk/a-lithium-battery-charger-with-load-sharing/ (http://blog.zakkemble.co.uk/a-lithium-battery-charger-with-load-sharing/) but as I’m lacking acces to pcb and wut like the bord to be as small as possible

any suggestions where I can find a circuit that fit this needs? Preferably premad so I only need to connect my battery and circuit
 
Extra question
the adafruit charger is rated at 1000c is this much ore to little for the battery mentioned above ?
 
Title: Re: lipo loadsharing circuit fit my needs / scourcing issues
Post by: Audioguru on June 21, 2016, 11:40:48 pm
Lithium batteries that are Chinese, no-name-brand, high capacity and are sold on ebay are frequently fakes.
https://www.youtube.com/watch?v=eOshOXcSkDA (https://www.youtube.com/watch?v=eOshOXcSkDA)
Title: Re: lipo loadsharing circuit fit my needs / scourcing issues
Post by: Signal32 on June 22, 2016, 12:28:26 am
Currently the highest capacity 18650 battery is 3400mAh, perhaps 3600mAh, and they are ofcourse very expensive. The ones you linked to are most certainly fake and probably have <1000mAh worth of capacity. Extract the cells from a laptop battery for good price/quality.

"the adafruit charger is rated at 1000c"
I think the model number is 1000c, it is rated for 1000mAh. Anyway the only thing that will happen is the battery will take more time to charge, it's not that it will not work.

Perhaps this might work for you:
http://www.ebay.com/itm/0-5A-Single-cell-Li-ion-Battery-Protection-Board-Mobile-Charging-Boost-Board-/231319638186?hash=item35dbb990aa:g:pD0AAOSwPe1UAHwY (http://www.ebay.com/itm/0-5A-Single-cell-Li-ion-Battery-Protection-Board-Mobile-Charging-Boost-Board-/231319638186?hash=item35dbb990aa:g:pD0AAOSwPe1UAHwY)
Title: Re: lipo loadsharing circuit fit my needs / scourcing issues
Post by: simondid on June 22, 2016, 02:24:09 pm
thanks for the ebay link :P
so a few questions the module has 0.5a charring lets say i'm using 6 batteries in parallel will make it a bad for charring (like damage and stuff) ore just a super slow charge?
Title: Re: lipo loadsharing circuit fit my needs / scourcing issues
Post by: Signal32 on June 22, 2016, 06:06:00 pm
Yes, only issue would be charging would be slow. 6 2500mah Batteries in parallel would be charged (from complete discharge) in aprox 30 hours.