Or maybe purchased Nicads. Just about double the range. Yes when charging even the bad boys will taper naturally. Start at 12 to 20 amps. Not quite top voltage. As the voltage rises and the batteries charge the batteries will reach top voltage and the current will naturally taper down to nothing eventually. I usually stop charging at 1 amp. 12 amps continous might stir up a golf cart battery. Now I'm out on a limb. Lawrence Rhodes.... ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, October 07, 2002 10:08 PM Subject: Re: Tropica update/charger chip.
> Lawrence, > > I'm certainly not a charger expert. The way the bq2003 is used in the Tropica charger (oh I'm out on a limb here)is as a controller for a buck converter. It turns on a FET sending current through an inductor and then the batteries. When the current reaches a programmed threshold it shut it off. Current is regulated by adjusting the pulse width. There's really no output that can turn off a charger. When 2003 senses the threshold voltage, it just quits turning on the FET. I'll let others explain the details of a buck converter. > > My problem is that it looks to me like in this configuration, it just keeps pumping out 12 amps until a threshold voltage and then shuts off. This doesn't sound like a valid charging method for lead acid. Is this why everyone I know of with a Tropica has replaced the charger? > > Steve > > > In a message dated Mon, 7 Oct 2002 11:41:57 PM Eastern Standard Time, [EMAIL PROTECTED] writes: > > > > > > > The charger chip that senses current and voltage is a nice feature. Can > > these chips be added to a charger like the B&W or maybe a variac bad boy. > > It seems that that chip and a relay would be all that is needed to shut down > > any circuit. Lawrence Rhodes... > > ----- Original Message ----- > > From: <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Monday, October 07, 2002 9:12 AM > > Subject: Tropica update > > > > > > > Last Thursday we went to DMV to start the "adventure" of getting our never > > registered 1995 vehicle registered. I had pretty low expectations for this > > first trip based on the experience of others. Well, I was wrong (again)and > > we came home with a red temp sticker good through year end after just an > > hour! Next it's off for a CHP inspection. Last Friday I was able to drive it > > to work, about 14 miles each way. I can charge at work so it got a drink > > before going home. > > > > > > Speaking of charging, I've got the schematics for the Tropica charger. > > Thanks Matt! I was looking over it this weekend and it's "brains" are a > > BQ2003 which seems to be a NiCad charger. If I understand the options they > > have it wired for, it does a constant current charge of 12amps to a set > > voltage and then shuts down. That doesn't sound like a good plan for lead > > acid does it? I looked at another part from Benchmarq, the bq2031, which is > > designed for lead acid. It has a constant current bulk charge followed by a > > constant voltage charge and terminates on hitting a min current or a delta > > voltage. The parts look close in the support they need but certainly not pin > > compatible. Any comments on the wisdom of replacing the > > 2003 with the 2031? > > > > > > thanks, > > > Steve > > > > > > > > > >
