The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
NNTP-Posting-Date: Mon, 25 Nov 2002 13:01:01 -0600
From: "Dave VanHorn"
Subject: Re: Questions on building a battery charger
Date: Mon, 25 Nov 2002 14:01:22 -0500
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
"Robert Richter" wrote in message
> I am building my own battery charger with a MAX712. (Probably seen
> this post many times) I am wondering what the charge efficiency of a
> NiMH battery is if I use the slowest charge time-out available on a
> MAX712 IC (the slowest time-out is 264 minutes). I would like to
> match my amp-hours of the batteries with this safety timeout with a
> comfortable margin for determining my sense resistor, or in other
> words, the charging current. The batteries are typical AA 1600mAH
Ideally, you set your timeout and high rate charge current to be a bit more
than the capacity of the batteries. You don't want the timeout to kick in
normally, it's just a backup in case the thermal or delta-V triggers don't
> Is it better on the crystals of NiMH batteries to use the slowest
> charge rate or a faster charge rate, such as one hour? Speed is not
> as much of an issue to me as I want the charger to be "intelligent."
> The original charger was a trickle-charger that slowly cooked the
> batteries, so I want something a little better.
The max712 still trickles the battery too fast.
C/300 is where it should be.
I've used this chip before, and I've given up on it.
We are rolling our own chargers, based on the Atmel Tiny-26 processor, with
It's less expensive too, about $1 less in production quantities.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup