Has anyone made a circuit that recharges batteries without having to take them out of your bot and put them in a charger? I would like to be able to plug my bot into an ac/dc adapter and charge it without having to remove the batteries.
I am assuming you have to use caps to keep voltage in check as well as determine when the batteries are fully charged to keep them from being damaged.
Also I'm not sure what I don't know ;) Anyone have any suggestions or experiences with this?
can’t help much, only thing
can’t help much, only thing i can tell you is that i saw some battery charging ICs, no idea on how they work though.
It is going to depend on
It is going to depend on what type of battery. Different types of batteries have different indicators of when they’re charged and some require careful regulation of heat buildup. Find some examples of chargers online (sparkfun has them for sale) and look at what they use. Then do some research has to how and why they work. Aside from that you will need a circuit bypass that will cut power to the bot when the charger is plugged in. Pretty easy to do and many of the dc plugs have this built in already.
battery charger link
This link http://adamone.rchomepage.com/guide3.htm taught me about chargers. Some basic circuits are shown for different chemistry batteries. But the circuit for a pulsed charger (which is described on this page) is sadly missing.
But you are a robot builder. So you already know how to program a micro controller to do pulse charging! Or you could ask your LMR buddies for suggestions.
Hootyhoo is right: do not connect your robot to external power and batteries at the same time. Always (automatically) disconnect the one when plugging in the other. See http://www.robotroom.com/Traffic-Light-Decorative-Desktop-Toy2.html for an excellent desciption why and how.
you can also check out
you can also check out maxim-ic.com
They’ve got ic’s for all types of battery managment and most have some sort of article on their use.
I’ve been eyeing their products for a while…
wouldn’t it be possible to
wouldn’t it be possible to modify a cheap AA charger?
As stated above, it depends
As stated above, it depends onthe type of battery that you charge. If you use the wrong charger those $20+ battery packs can get severly damaged making them loose their charge faster.
I got some free samples of
I got some free samples of the max713 nimh/nicad charger IC a while back. It works for me, but some of the calculations are a bit tricky and I`m still not 100% trusting of it with my batteries so usually I keep an eye on it and the clock at the same time.
