Date: Mon, 29 Apr 2002 22:53:04 EDT From: [EMAIL PROTECTED] Subject: Re: [LIB] Solar Panels
In a message dated 4/29/02 8:35:21 PM Mountain Daylight Time, [EMAIL PROTECTED] writes: > > >There was some interest in using the Libretto with solar panels a > > >while back. I think I might have found some that will work if the > > >information I found is accurate. First I found out that the Libretto > > >takes about a amp of current from the AC adapter when it isn't > > >charging and is being used. Second I found that when the Libretto > > >is off and charging it uses about .6 amp. Has anyone measured the > > >current that can confirm these measurements? > > > > Well I found some very different results with my L50 when I was mucking > > around with an automobile laptop adapter ... the current consumption > > actually went UP when I switched it off (presumably because the battery > > went into fastcharge - it was dead at the time). During running, I was at > > about 800mA, in the first bit of charging I was in excess of 1.5A! Enough > > to brown out the 1A regulator I was using at the time ... > > > > Not surprizing. 1 + .6 is about 1.5 amps. A battery usually takes a > ton of current in the intial stae of charging. This does show that it > should work with solar. The peak current will be less because there > will be less to draw on but over a long time like a couple days the > battery should reach a full charge. It would be nice if there was a > software settable switch for battery charing so a person could turn > it off if they wanted. Thanks for the info > > > > > > So with this I found > > >some setups that might work. They provide about 1.2 amps or > > >greater which would be enough to run but you'd really want to shut > > >it off to charge otherwise it'd take about three days to fully charge > > >the battery. > > > > Well depending on what the situation is, it might well be better to get > the > > solar panel to charge a lead acid cell and run the libby off that ... > > charging circuits that will properly and efficiently charge a lead acid > > cell from a solar panel are readily available whilst charging a 15V Libby > > from a 12 volt solar panel would be considerably less efficient. > Reasonably > > lightweight lead acid cells of several AH can be had relatively cheaply > and > > will run a libby (with an auto adapter or using a tricker) continuously > for > > at least a day (plus IIRC the discharge curve is considerably nicer on a > > lead acid cell) ... > > > > I am trying to avoid anything but the libretto and auto adapter and > solar panel(s). Additional batteries are bulky and heavy and are > difficult if a person is on the move. Especially if you have to carry > everything. Even a li-poly or li-ion in the 6-8 Ah range will weigh 2-4 > pounds. A person could add a third panel for less weight to make > up for lost effiency. Even without an extra battery the setup will > weigh a good 7 lbs and is pretty bulky. > > John I had posted awhile back on the solar panel idea, and have the same thoughts on weight &/or bulk as John. The panel would be used only when one was away from all other power, which means carrying or moving the equipment. One thought I've started to work on is to connect a solar panel to a modified Toshiba battery charger. You'd have to bypass the 110VAC/DC transformer, and I haven't opened up my spare charger to see how feasible that is. Given it's workable, you'd simply run the Lib on batteries which you'd charge independent of the Lib. Whether the charger could handle the variable current from the panel I don't know...but better the charger than the Lib. It would add some weight, but less than a lead-acid battery. Still working this one out... Lee ************************************************************** http://libretto.basiclink.com - Libretto mailing list http://www.silverace.com/libretto/ - Archives -------TO UNSUBSCRIBE------- Reply to any of the list messages. The reply mail should be addressed to: [EMAIL PROTECTED] - Then replace any text on the message's subject line: cmd:unsubscribe --------TO UNSUBSCRIBE DIGEST------ Do above but with this on subject line: cmd:unsubscribe digest **************************************************************
