Battery Charging

[Dragon Tamer]

I've been asking for a while about charging a 9V battery for an application of mine, since Li-ion, Li-polymer, NiMH and NiCd seem to be the most common types of batteries i wanted to make my charger capable of charging them. i have been looking on Newark.com and i can't find the IC I've been looking for. the closest charge voltage was either 10V or 8.4V, the only IC with the capabilities of charging up to 6 series cells is impossible for me to solder onto the board. No matter how hard i try i can't find an IC that can charge a 9V batt. So can someone please show me a site that I can buy from that works with a 9V. the input voltage for the IC can be anything under 30V. AND I DON'T WANT LINKS ON INFO ABOUT CHARGING BATTERIES!!! I HAVE NEITHER THE TIME, THE PATIENCE OR THE ATTENTION SPAN TO REMAIN FOCUSED. The chip should do everything that i need to in a much simpalar manner. if you just give me the link to the site or preferably where i can find the chip, i will look up the datasheet and take care of everything else.

Batt Types

Batt voltage

number of cells (NO i can't solder that)

 

[Boncuk]

MAX712.

Controls charging of one to sixteen NiMH cells. (hardware programmable)

Boncuk

P.S. Posting using capital letters is considered shouting. Please don't shout anymore.

 

[Mr RB]

LM317 set to the max voltage for the charged battery, and a resistor in series with it's input to limit the peak charge current. Requires LM317 and 3 resistors.

 

[Boncuk]

Hi MrRB,

the LM317 will work fine charging lead-acid-batteries.

NiMH batteries require zero voltage slope to determine charge complete. The MAX712 has all the functions necessary not to overcharge an NiMH battery and monitors battery temperature as well.

I think using that chip will make charging simple and safe.

Boncuk

 

[szabi]

Hello and Happy New Year!

 

[Dragon Tamer]

MAX712.

Controls charging of one to sixteen NiMH cells. (hardware programmable)

Boncuk

P.S. Posting using capital letters is considered shouting. Please don't shout anymore.

thank you for using giving me such a straightforward answer. the only reason i used caps was because in chat, everyone kept getting sidetracked by everything else and started lecturing me about what i need to do.

LM317 set to the max voltage for the charged battery, and a resistor in series with it's input to limit the peak charge current. Requires LM317 and 3 resistors.

are you talking about just hooking up a 317 to the battery? i tried that before, first it fried the 317, then it fried the battery.

 

[Sceadwian]

Dragon, the lectures are because you're just slapping things together without knowing what you're doing. The LM317 is overload protected if you fried an LM317 and then a battery you hooked something up wrong it's that simple. If you have neither the time or willingness to pay attention then buy one don't try to build one.

 

[Dragon Tamer]

the 317 was fried because i did not have it hooked up properly, and it happens to me a lot. transistors are the most common device subject to overheating and shorting out.

 

[Sceadwian]

If you're not capable of hooking up a three terminal chip properly why do you think you're capable of hooking up one that has 8 or more? You want results you want them now and you want them without learning. So how exactly are we supposed to help you?

 

[Dragon Tamer]

embarasing but true, tried to use the 317 in a dual rail, back when i knew little to nothing about electronics. i thought that the 317 could be used to replace a 7912 by pluging it in in reverse. i wont be doing that again but, i am better than my dumb as dirt cousin, he thinks that you can exceed the maximum rated voltage on a part if you maitain the wattage disipation (by decreasing the current).

 

[mneary]

but, i am better than my dumb as dirt cousin, he thinks that you can exceed the maximum rated voltage on a part if you maitain the wattage disipation (by decreasing the current).

There will come a time when you'll want to become the best you can be, instead of finding someone who isn't as 'good'.

 

[Dragon Tamer]

it's not that he's not good, he has the potential, he just lacks the effort and the common sense to make an effort to learn, and most of the time his ideas are stupid, and dangerous! some of the things he does makes me scared for my life!

 

[Sceadwian]

Dragon Tamer

it's not that he's not good, he has the potential, he just lacks the effort and the common sense to make an effort to learn, and most of the time his ideas are stupid, and dangerous! some of the things he does makes me scared for my life!​

That is the very definition of 'not good' Unrealized potential is something the person needs to work on and means nothing if effort isn't applied.

 

[Dragon Tamer]

exactly, one of the reasons he scares me is because he tried to charge a 1uF 6.3V capacitor by sticking it into an ac outlet. yes, he did have to go to the hospital, no he was not happy, looking back on it... Yes it was pretty fun. and i learned something that day.

 

[Birdman Adam]

Aren't all caps made today designed to pop gracefully (slits in metal top), instead of exploding?

 

[Dragon Tamer]

i didn't know there was such a thing as exploding gracefully. but back to seriousness real quick, i was looking at the data sheet for the MAX712, what is the load for? and can R1 be any value as long as it's over say 100 ohms? those 2 things are not explained in the data sheet.

MAX712

 

[audioguru]

The load is what the battery would normally power but this battery charger IC can power the load at the same time it charges the battery.
The datasheet explains how to simply calculate R1 on page 6.

 

[Dragon Tamer]

oh, ok. thanks

 

[Sceadwian]

birdman, there is no way to apply 120V AC to a 6.3V 1u capacitor and have anything even closely resembling 'graceful' occur =O Even the ones with the slits on top I've seen bad caps that blew the entire casing clean off the leads with the slits perfectly intact.