Re: Battery Boxes...What One Company Designed

[Marc F Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On 16 Sep 2005 12:23:51 -0700, "Too_Many_Tools" <too_many_tools@xxxxxxxxx>
wrote in message  <1126898631.801389.317530@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>Since I am starting the homepower/automated house journey, I have been
>collecting surplus commercial equipment that might prove useful. One of
>those items was a surplus Best battery box for a large UPS. Some
>comments on the construction and design follows.
>
>The box is designed for sealed 6v batteries (two banks or four) with
>the second bank located above the first. The cabinet is metal with
>galvenized trays for the batteries to sit in. The box was wired for 12v
>at 200 amp with commercial welding cable. There are two in line fuses,
>one per bank. The cabinet is on wheels. The cabinet has two vents
>located on the back of the cabinet, one lower and one higher. The
>cabinet is NOT actively ventilated but relies on natural convection. On
>the front it has a single heavy duty switch to switch the direct
>current. The switch has a ceramic resistor on it (to quench arcs when
>switching?).
>
>Several things caught my attention. The use of metal throughout the
>box...I would have expected fiberglass or plastic for corrosion
>resistance. Next was the absense of an active ventilation system.
>Third, the lack of an integrated charger for the battery box. I assume
>the batteries are charged through the UPS.
>
>I plan on making some mods to this box for my home system.
>
>One is to make plastic tray inserts to keep acid at bay.
>
>Next is an active ventilation system.
>
>Third is to consider doing some type of a sliding tray on the bottom
>level to allow one to access the batteries easier during maintainance.
>
>Fourth is to incorporate a charging system.
>
>Fifth is to place meters on the front to monitor voltage and amperage
>and add the option for remote sensing.
>
>Sixth rewire it for a different voltage (it was 12v at 200a)...any
>suggestions?
>
>I would be interested in any suggestions or comments as to what you
>have added to or wish you had designed into your system.
>
>Thanks for any and all suggestions.
>
>TMT

Assuming that you are in US:

Check the National Electrical Code (NEC) which addresses both batteries and
low voltage.

Make sure that the DC/charging system is isolated from the AC, draws not more
than 20 (IIRC) amps source AC, is UL-listed and is not connected to earth
ground.

Above 30 volts, or if the system is not isolated, the NEC is more restrictive.

(FWIW, I have some of your questions.  I have a growing 28vdc system.
A natural gas-powered 28VDC generator awaits installation. )

Marc
Marc_F_Hult
www.ECOntrol.org