[Shop-talk] EE question

[Bill Gingerich]

We have several 3, 5, and 10 KVA APC rack mount UPS' at work, and all of
them have plugs for eternal battery packs.  I believe they are 48 volt, but
I'm not 100% sure.  I would think finding used units that will take external
batteries would be fairly simple.

BillG
Newalla, OK



-----Original Message-----
From: shop-talk-bounces+bill=gingerich.us at autox.team.net
[mailto:shop-talk-bounces+bill=gingerich.us at autox.team.net] On Behalf Of
Randall
Sent: Saturday, November 03, 2007 5:20 PM
To: shop-talk at autox.team.net
Subject: Re: [Shop-talk] EE question

> I know there are 28V Li-ion tool chargers but I don't think 
> they would work for lead acid.

Are you sure they are lead-acid ?  The ones my helicopter pilot buddy used
to give me were nickel-cadmium.

FWIW, some APC UPS units at least used to have external battery connections.
Even if you had to modify the charger portion somewhat for a different
battery voltage/chemistry, I would think a used UPS would be a much cheaper
starting point than trying to source the components (and design) to build
your own from scratch.

Randall