Re: Running NEC UL on C-cell nicads

Dave, MRO1-3/C6, DTN 297-8251, 508 467-8251 16-Sep-1994 1430 ((no email))
Fri, 16 Sep 94 14:33:18 EDT

Hi,

A few responses to various feedback:

>From David:
>Subt: Re: Running NEC UL on C-cell nicads
>HI!
>
>I'd like to know if anyone has the description for the pinouts in the power
>supply/recharger. I'd like to replicate what the person who posted the msg.
>on using D cells for powering the UL did.

>One question I have for this person is whether he was able to initiate comm-
>unication with his PC via Laplink before he used the substitute cell? Can
>he do it with the regular cells? Last; has he tried to use 10 cells as he
>proposed in his post? Oh.. also, did he plug in the disk drive as well?

My inputs:

I used C cells as stated in the subject and text. Although true D cells have
more power than C cells, they are bigger, heavier, and many aren't true D
cells. Many nicad D cells have the same sub-C battery inside a bigger case.
This explains why most of the mass marketed nicads sell the C and D sizes at
the same price. I believe that both Radio Shack and Digikey sell true D cell
nicads (which have 4 Amp Hr capacity), but they naturally cost more than the C
cells. In addition to the higher cost, I wouldn't want to lug that many D cells
around.

I had good Laplink performance with the power supply, the NEC battery, and my 8
*fresh* nicads (which initially measured 10V with no load). It was only as the
nicads started drooping that the desktop couldn't read the notebook's data.
I haven't tried it with 10 batteries yet, and I'm pretty sure that the disk
drive won't work unless I supply the 5V that it needs to run.

Frank's Comments:
> After reading the post about using "D" cells, it occured to me that buying
> a small 12v "gel cell" would be a good idea, a gel cell is a lead acid
> battery much like a car battery except the electrolyte is sealed inside
> the battery, if you have a UPS, it has some in it.
> They are available from places
> such as Digi-key, they also stock the connector for the Ultralite power
> as well as the connector for the serial port. The number for them is
> 800 344 4539 (800 digikey), the part number for the serial connector is
> CP2090ND the current price is $1.65 US. The power connector is the same
> as the one used for Mac printers, also known as Philmore EMA8.

My input:

I looked at Digikey's gelcells when ordering my power connector. Although they
would be a little more compact, I decided against them. The $30.04 price (of
the comparable 2.2 Amp HR battery) compared unfavorably against the <$20
($3.99/pair * 4 or 5) of the retail nicad C cells. The gelcell also weighs more
than 10 C cells and I am not sure about any warrantee. Also, with my slick
battery case, I can grab new, charged batteries off of any retail shelf in the
event of an emergency. Of course, I would be careful about the battery
voltages: blindly substituting ten 1.9V (rechargable or not) alkaline cells for
ten 1.2V nicads would probably make alot of smoke!

Disclaimer: the above text is unreal, you didn't read it, and you shouldn't
try it.

Dave Brown

dbrown@milkwy.enet.dec.com