Go Down

Topic: rechargeable battery (Read 4658 times) previous topic - next topic

acorbi

Hi,

im working on a project with arduino, led matrix and accelerometer, it should be autonomous , so the use of a battery is mandatory. Also it should be rechargeable so i ask you guys wich is the best solution.

I suppose Li-ion batteries is a correct choice
How is it to recharge the batteries through the usb interface? Do we need a recharging circuit ? how much voltage should it give to feed arduino +the matrix+the accelerometer?

So, i thanK you if you guide me with brief infos



kg4wsv

Lithium batteries are particularly intolerant of incorrect charging; simply connecting the battery to USB would be a good way to generate a fire or explosion (no, I am not kidding).

Since Li technology batteries are ~3.6V, you need either a 3.3V arduino variant with an LDO regulator, 2 cells, or a boost regulator.

There are ICs available specifically designed to charge Li cells from USB voltages (MAX1555, etc).

-j


retrolefty

In addition Li batteries have to be protected from over discharge to prevent permanent damage, so some kind of low voltage cutoff/turn off is required.

Unless you really require the higher power density ( you also pay for this increased density) you are probably better off with other less fussy types of rechargeable batteries.

Lefty


acorbi

Hey, thanks both of you for the answers.

Soo, which solution would you choose to power an arduino + a led matrix + an accelerometer and provide it with rechargeable feature?

acorbi

I think a nice solution would be this:

http://www.sparkfun.com/commerce/product_info.php?products_id=726  

with this

http://www.sparkfun.com/commerce/product_info.php?products_id=341

am i right?

gnu_linux

Yes you will need those parts from sparkfun, a lithium backpack from liquidware or NiMH batteries

http://www.liquidware.com/shop/show/BP/Lithium+Backpack+Stealth

http://www.adafruit.com/index.php?main_page=product_info&cPath=17_22&products_id=80 and http://www.all-battery.com/tenergy9v250mahnimhhighcapacityrechargeablebattery.aspx and http://www.all-battery.com/v3969a1plug-intypespeedyrechargeablebatterychargerforaaaaa9vbatteries.aspx

Or you can use a 6 AA battery holder with a 9V battery connector and AA NiMH batteries http://shop.vetcosurplus.com/catalog/product_info.php?products_id=965 and http://www.all-battery.com/aasizenimhrechargeablebatteries.aspx and http://www.adafruit.com/index.php?main_page=product_info&cPath=17_22&products_id=80

AA and AAA NiMH batteries are particularly useful since you can use them for your *duino as well as other devices :)

Go Up