Re: Cache Battery question

[DrFranken <midrange@xxxxxxxxxxxx>]

No question they aren't going to put anything with 'fast charge' 
capability in there. That would add weight, cost, and importantly load 
on the PCI slot power as well. Consider that in many cases there are 
(were?) batteries in 2 of 3 slots at times, if they all needed a fast 
charge that would be a design issue right there.

Also consider that 99.999% (or more one would hope) of the time that 
battery needs little to no charging, just keep it topped up occasionally 
so it's available. Then consider that of the times there IS an outage 
they are normally not very long so the battery doesn't get drawn down 
much. I wonder how many cache batteries spend their ENTIRE life and 
never once get utilized, that has to be a fair number of them.

However since we know shipping these batteries fully charged is no 
longer legal here there MUST be a way for them to charge. Adaptec (and 
others) have chargers on their boards, this isn't new ground we're 
plowing here.

I can see it now, IBM shows up with 30 new cache batteries and plugs 'em 
all in and you roll in the 100A 220V charger with the #0000 cables and 
clamp onto these copper bolts hanging out the sides. 7.5 seconds later 
'all charged up'!  I see some Franken' coming here... :-)

We used to start the JD 4010 Diesel in the winter with the DC Welder. 
Set it to 400 Amps, clamp on one side ham a stubby welding rod on the 
other side then turn the key. What could go wrong? It's not like 
batteries produce explosive gasses or anything and welders don't make 
sparks do they? :-)

        - Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 5/18/2015 1:22 PM, Buck Calabro wrote:

> Doc,

> I'm a ham.  I've build, debugged, and busted my fair share of power
> supply and battery charging circuits - enough to understand the
> technology well enough to speak about it in a public forum.  I don't
> know the specifics of any IBM cache battery charge controllers though.
> In layman's terms, Holger is describing the difference between a 1 amp
> trickle charger and a 100 amp boost charger that one would use for a
> car.  Every computer problem needs a car analogy :-)
>
> If IBM's charge controller is built along the lines of a trickle
> charger, I fully expect that they have a spec which says that newly
> installed cache batteries need to be within X% of full charge, where X
> is a number within the controllers ability to source current.
>
>    --buck