Xref: utzoo rec.autos.tech:21967 sci.electronics:17974 Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!cs.utexas.edu!asuvax!mcdphx!mcdchg!laidbak!jeq From: jeq@i88.isc.com (Jonathan E. Quist) Newsgroups: rec.autos.tech,sci.electronics Subject: Re: Charging two 6 volt car batteries Message-ID: <1991Feb22.160837.18501@i88.isc.com> Date: 22 Feb 91 16:08:37 GMT References: <74@owl.ukc.ac.uk> Sender: usenet@i88.isc.com (Usenet News) Organization: INTERACTIVE Systems Corporation, Naperville, IL Lines: 31 Nntp-Posting-Host: laidy.i88.isc.com In article <74@owl.ukc.ac.uk> abs@ukc.ac.uk (A.B.Smith) writes: > >I just bought two six volt car batteries for my car (they are connected >in series to give a 12 volt system). Oh, you own an MGB, then? >The question is, can I charge them in parallel or series to cut down on >the time/effort ? I did try charging them in series, but got a very low >amp reading (was this because the charger couldn't cope?). I'm assuming you used a 12 volt charger to charge them in series. Since the batteries are new, the current draw from the charger will be relatively small, since a battery fresh from the box is generally about 65% charged already, possibly more. You could charge them in parallel with a 6 volt charger, but this will take twice as long since each battery is only getting half the current. (E.g., if you have a charger that produces 6V @ 2A or 12V @ 2A, charging in series gives 2A through both batteries; in parallel would give each only a 1A charging current.) As someone else mentioned, if one battery is bad, you're better off charging seperately. With new batteries (or batteries with no serious problems that have been wired in series) charging in series should give good results. -- Jonathan E. Quist INTERACTIVE Systems Corporation jeq@i88.isc.com Naperville, IL DoD #094/ '71 CL450-K4 "Gleep" Brought to you by Super Global Mega Corp .com