Battery backup setup

[colinhowlin]

Hi

Looking to deploy a WS-12V-DC on one of our sites with a battery backup system in place.
New territory for me - how does everyone else do this?
What gear do you use as far as battery, controller etc are concerned?

Thanks
Colin

[rockhead]

I reaaaaaly like AGM batteries as they are unspillable and will only off gas if massively overcharged. Samlex makes good simple reliable charge controllers, there are many more.

[sirhc]

If using a WS-12-DC unit you need 48V +/- conditioned power.

The WS-12-250-DC unit will accept 9-60V unconditioned power.

[colinhowlin]

Thanks,

When you say it needs 48V+/- conditioned, I take it there is very little tolerance for voltage fluctuations?

So what's my shopping list!
I need something to take mains AC (240V), which will be used to primarily power the switch.
Batteries are for backup in case of mains failure.
Controller?
Rectifier?
Pretty clueless in this area.

[sirhc]

If you are on grid then I would do this:

Trip Lite 750 or 1250 watts inverter charger
They make 120V and 220V versions.
http://www.tripplite.com/products/power ... hgod-woOKQ

2 to 4 AGM 12V batteries
I use Optima Blue top
http://www.optimabatteries.com/en-us/pr ... hgodYXMFEg

I would use an AC powered switch not a DC switch since your on grid


All this information and more is already on this forum and discussed many times just do some searching

[lligetfa]

I guess it boils down to how (un)reliable the grid is and how much offgrid runtime is needed. A UPS is simpler but will limit the runtime. Once power fails, you are babysitting it more than a DC site. A UPS may need additional monitoring to know when to ignore the alerts and when to act. Also depends on what mitigation steps are available. Do you drag out a genset? Shed load?