# looking for advice on battery backup for home



## MACSPECTRUM (Oct 31, 2002)

I've been trying to figure out the most cost effective way to create a battery backup system for my home
(I prefer NOT to use a fuel based generator as they are noisy and I would need to store fuel onsite. I also don't want to bring natural gas to my home to avoid another utility bill. I will be using a wood stove for backup heat)

We have outages that usually last from 18 - 48 hours.
I keep a battery powered (w/ hand crank) Grundig radio and would use a flash light and candles for lighting.

I have a one floor cottage heated with baseboard heaters with a 30" crawl space which can only be accessed from outside. Crawl space is insulated and heated with electrical space heater.

Summer blackouts are annoying, but I can always make a BBQ or go play golf and there are lots of people up here for entertainment. The worst is a blackout during winter when population drop by 95% and entertainment is television.

Here's what I want to keep running in the event of a blackout;

1. water pump 1/2 horse power (electrician pulled power for pump as a plug iside home for easier access to backup power)
2. fridge, 4.5 amp
3. macbook, satellite modem, router

I don't think my 62" tv can be backed up effectively. I may buy a small tv or some device to run tv on my laptop, but that would be a luxury.

Here's what I have found at Cdn. Tire prices reflect items on sale

*OPTION 1*
Powerpack 1200 - $250 (sale) 60 amp hours, 1200 watt
very similar to this unit, except 1200 watt
Xantrex XPower Powerpack 1500
Canadian Tire Powerpack 1200
additional Deep cycle battery 100 amp hours @ 100 hr. rate - $250, maximum of one
Canadian Tire deep cycle battery
additional battery needs to be charges separately from Powerpack 1200 (cdn tire version of 1500)
need external battery charger @ $200
$500 = 160 amp hours each "station"
$1500 for 480 amp hours (might not be enough wattage for pump startup)

*OPTION 2*
PowerSource 1800 - $350 (sale price) - 60 amp hours, 1800 watt (3600 peak), NO extra batteries
Xantrex XPower PowerSource 1800
Units discounted by $100 - I was thinking about 5 of these
$1750 for 300 amp hours

*OPTION 3*
PowerHub 1800 - $900
Xantrex PowerHub 1800 - Canadian Version
additional Deep cycle battery $250 each, maximum of 2
$1400 for 200 amp hours

OPTIONS 1 and 2 are portable units and can be stored away when not in use.

OPTION 2 can be setup as a UPS for auto-backup, but I don't want to use backup power in case power goes out while I am not here, except for fridge.

OPTION 3 would require floor space I may or may not have and is NOT portable.
Can be hooked up to wind/solar in future as it already has these hookups.

Any comments or suggestions or experiences would be most welcome.
I've been agonizing over this for many months now and don't want to be caught when winter comes.

Also, can anyone explain amp hour ratings as per 5 hr rate, 20 hr. rate, 100 hr. rate?

Thanks in advance.


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## Demosthenes X (Sep 23, 2004)

The Eliminator power packs are very good, and have been very popular since they were introduced. I don't have much experience with the larger ones, but I've used a number of the smaller ones to run various things, and I can say they work very well.


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## krs (Mar 18, 2005)

MS -

The first thing I would do is spend $20.- or maybe $40.- for two, and buy these UPM electric power meters at CTC.
Plug each device you want to back-up in case of a blackout into those and run them for a week or two to find out what the average power consumption is.

You list those three items:

1. water pump 1/2 horse power (electrician pulled power for pump as a plug iside home for easier access to backup power)
2. fridge, 4.5 amp
3. macbook, satellite modem, router

The first two will only run intermittently, the last one probably longer but you could always shut down the computer and associated equipment when not in use.

Once you have your average daily power consumption, you can add a safety factor and then multiply it by the number of days you need the backup power to last which you can then translate into amp-hours to focus in on the size of system you need.
I don't know what you need water for, but a toilet consumes a lot of water unless you have one of these really low-flow ones. You may want to think of upgrading your toilet or buy one of these camping ones for an emergency.

As to question, can anyone explain amp hour ratings as per 5 hr rate, 20 hr. rate, 100 hr. rate?
I don't know much about batteries, but here are the basics.
A 100 amp-hour battery for instance will theoretically provide 100 amps of current for 1 hour or 1 amp of current for 100 hours or any other factor in between, ie 2 amps for 50 hours, 4 amps for 25 hours etc.
That's in theory. In practice it's a bit different in that there isn't such a straight linear relationship, so the battery manufacturer specifies the battery amp-hour rating at a specific discharge rate. So if a battery is specified at 100 amp-hours at a 20 hour discharge rate, the manufacturer will 'guarantee' that the battery will provide 5 amps (100/20) for 20 hours, but he makes no 'guarantees ' about performance at any other discharge rate.

Now remember, the "amps" may sound great, but those are at the *battery voltage*, not at the 115 VAC you need to run your fridge etc.


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## MACSPECTRUM (Oct 31, 2002)

> The first thing I would do is spend $20.- or maybe $40.- for two, and buy these UPM electric power meters at CTC.


that's a good idea
it's on tomorrow's list of things to buy

thanks !!


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