RE: (ET) Charger Alternative: 3 Soneil 1206S Chargers, together for $100

["Markus Lorch" <mlorch vt edu>]

Chris,

you are correct and I plan to build a battery monitor similar to 
the one proposed by Chris Z. Up to now I have been monitoring the
chargers and batteries pretty closely with a voltmeter.

The reason why I NEED a battery monitor is the fact that I have
batteries of different capacity. I recently damaged one of my
smaller 12V when I was running the ET all empty (I thought) My
larger batteries still had plenty of capacity left when the small
one was all empty which caused the small battery to be reversed.
I am glad I had a spare. I'll be very careful not to do this again. 

Markus

> -----Original Message-----
> From: Chris Tromley [mailto:chris_t microtrac com] 
> Sent: Thursday, July 01, 2004 1:48 PM
> To: 'Markus Lorch'; 'Elec-trak Mail List'
> Subject: RE: (ET) Charger Alternative: 3 Soneil 1206S 
> Chargers, together for $100
> 
> 
> Markus Lorch wrote:
> 
> > Hi all,
> > 
> > the talk about chargers lately and somebody's post on a
> > Soneil 36V charger prompted me to report on my experiences 
> > with three Soneil 12V automatic 
> > chargers. While they are 3 Amp the manufacturer claims they 
> > are as fast as standard 6 Amp chargers.
> > 
> > I opted for 3 chargers for two reasons: (thanks to David
> > Roden for valuable
> > tips)
> > 1. I had differing battery capacities (2 90Ah 12V and two 200 
> > Ah 6V Gel) 
> > 2. Low Price
> > 
> > I bought the three chargers for about $100 (batterymart.com
> > sells them as "battery defender" 
> > http://www.batterymart.com/battery.mv?p=ACC-> 1206WB) 
> > and 
> > hooked each of them up to a 12V battery (2 6V 
> > batteries respectively). 
> 
> Hi Markus,
> 
> "Modular charging" like this has been discussed many times on 
> the EV discussion list.  It has all the advantages you 
> describe.  And one potentially big disadvantage.  If one 
> charger fails and you're not paying attention, you won't 
> notice the somewhat lower pack voltage when starting out on 
> what you *think* is a full charge.  As you discharge, the 
> batteries that didn't get charged get really hammered or even 
> reversed.
> 
> This is admittedly more of an issue with a road EV with many 
> batteries in series.  The voltage drop from one uncharged 
> battery will be easier to see if you only have 36 V.  Still, 
> you have to pay attention.  Chris Zach's monitor would be a 
> good thing to add to a modular system, allowing you to verify 
> that all batteries are ready to go.
> 
> Chris
> 
>