Prius traction batteries

[dcb]

got a link handy?

[bwilson4web]

http://focus.ti.com/general/docs/lit...Number=slua411

[dcb]

Ah, I did see that, thx. I remember saying "wow did they overcomplicate that!"

I'm hoping something a bit more like one of these will work as a current source (and not take much more than a bridge and caps from the wall as input)

[bwilson4web]

Agreed, it is complicated but I thought they were trying to use the battery charger chip to moderate the switching power supply output. This avoids the efficiency hit of a linear or transistor/MOSFET regulating power via current limiting resistors.

For tickle charging, I would just limit the voltage and let the batteries reach stasis. Low current at a fixed voltage and the problem is solved.

Bob Wilson

[dcb]

mostly the chip was to protect the batteries. If I can string 4 modules together and put an amp through them cheaply and without destroying the batteries, I can recharge in 7 hours ish. This is for a bike/scooter sized experiment so I'm not overly concerned w/efficiency yet, though I will certainly revisit it after looking at the kill-a-watt and the odometer.

[dcb]

here is a constant current controlled by an atmega, I should start there, as that looks like it makes it a software problem (as in bugs=smoke) to add some smart logic (i.e. peak detection, pulse trickle), and even has a separate voltage for the batteries. And I have a small pile of atmegas.

http://www.opend.co.za/hardware/nimh1/nimh1.htm

I'm gonna need a new thread though...

[bwilson4web]

You might also look at the MAXIM712/713.

Bob Wilson