Looking for a Deep Cycle AGM battery

[Ranga]

I'm after a 120AH battery. Best price I've seen is $315 for a Ritar brand from Springers.

Anyone know of a better deal in Brisbane?

This is to run a pond pump and will be charged with a 80W solar panel. If anyone has suggestions for another type of battery, please let me know.

[d2dave]

What is the current draw of this pump?

Dave.

[Ranga]

35W

[d2dave]

Is the pump going to be running after dark or just during the day?

Dave.

[bee utey]

Ebay. Lots of ex UPS batteries on there, take your pick.

[DEFENDERZOOK]

how much life could there be left in a ups battery that has been sitting on a float charge for the last 5 years.....?

ive been looking at these myself but have been too scared to spend the dollars and only have it last less than a year or so......

anyone have any experience with these......?

[Africampers]

I've recently purchased 2 X 120ah Fullriver AGM deep cycle batteries on Ebay - made in the USA with 2 year warranty - very high quality and fast delivery. I have no connections with the company - but its a good product and will gladly support them again.
Anton Africampers

[bee utey]

how much life could there be left in a ups battery that has been sitting on a float charge for the last 5 years.....?

ive been looking at these myself but have been too scared to spend the dollars and only have it last less than a year or so......

anyone have any experience with these......?
i bought a set of six 2V 275AH cells last year and they are going great. Most commercial UPS batteries get turfed way before their use-by date as 100% reliability is important. Yes there are risks but that is the way the cookie crumbles.

[drivesafe]

Hi Ranga, why the specific need for an AGM?

[Ranga]

Hi Ranga, why the specific need for an AGM?

I guess it doesn't really have to be AGM - I'm just after something that's reliable, and can handle running a 35W pump for 15 minutes every hour, 24 hours a day, and occasionally a few days with the solar panel.

[drivesafe]

Hi ranga, save your self a bucket load of money and just go with a standard flooded wet cell battery, a small cranking battery is about as cheap as you can get and this will easily do what you want.

[Blknight.aus]

Back of the napkin maths points me to....

about 55ah worth of battery should do what you need without risk of the battery overly discharging and shortening its life PROVIDING that it gets 8 hours of effective full power from the panel every 2 days.

add roughly 10AH per additional day you want to be able to go without sun but remember that means that at the end of the period of no sun for every additional 2 days you run uncharged you will need 1 more day of 8 hours effective full charge to bring the battery back up to full.

[drivesafe]

I got 4 days stored power from the 80w panel for every 3 days of sun.

Depends on panel efficiency and the regulator used.

[Blknight.aus]

I got longer but rounded all the partials against the battery and charge rate to make up for losses in wiring, pump loadings as filters clog and the battery discharges and a fair safety margin.

[Ranga]

I was told in QLD we only get about 6 hours of effective full power per day, but your advice gives me encouragement just the same.

So long as the system runs fine with the panels day in, day out, and the batteries can handle 4 days without them, I'll be happy. I plan the give the batteries a good charge on return with the C-Tek, so hopefully that should help maintain them.

I was considering a couple of these Powertech Monocrystalline Solar Panel - 80W - Jaycar Electronics (http://jaycar.com.au/productView.asp?ID=ZM9097&CATID=7&form=CAT&SUBCATID=920). Anyone know a better option?

So, what batteries do you recommend, and where should I get them from? If they're cheap enough, I'd rather get a bit more capacity than I need just to be sure.

Hopefully they'll end up cheaper than the $315 I was planing to spend on a 120ah AGM deep cycle!

[digger]

Is the pump going to be running after dark or just during the day?

Dave.

well, i would suggest that that very much depends on the battery...wouldnt you?:D

[drivesafe]

So, what batteries do you recommend, and where should I get them from? If they're cheap enough, I'd rather get a bit more capacity than I need just to be sure.

Hopefully they'll end up cheaper than the $315 I was planing to spend on a 120ah AGM deep cycle!

Hi ranga, just a suggestion but why not just get two small cranking batteries from K Mart or the likes and if you find you need more capacity, just add another battery.

A couple of 70 Ah cranking batteries ( total capacity 140 Ah ) should workout a lot cheaper that a single 120 Ah AGM.

Remember, the cheaper batteries are a trade off, they won’t have as long an operating life span but it will still work out about the same price in the long run and by using a few small batteries in the first place, you can then experiment to see what best suits your set up.

Just a rough calculation but 4 x 70 Ah batteries would give you 6 days operation with no sun and would not discharge the batteries below about 60%.


It would take 16 days of sunlight to fully recharge the batteries and operate the pump at the same time.

[incisor]

Dave's Interesting Things - 80 Watt Mono Solar Panel (http://www.davesitshop.com/davesitshop/index.php?_a=viewProd&productId=69)

[Mudsloth]

Don't be too scared of second hand batteries, just buy them from a shop and not ebay. I have 10 100ah batteries running various devices around my house, they cost me $100 each from battery stop and so far they have been as good as gold. If you're going to be using an 80 watt panel for 35w worth of draw I think you will find the battery will do bugger all anyway. Just make sure the regulator you buy has a dc load connection and the pump will operate directly from the panel for most of the day.

[Blknight.aus]

I was told in QLD we only get about 6 hours of effective full power per day, but your advice gives me encouragement just the same.




yep but that doesnt always include the partials... dead flat on the ground with no shade you can pull about 9 hours worth of full power out of a panel in the summer and 6 during winter.


Hi ranga, just a suggestion but why not just get two small cranking batteries from K Mart or the likes and if you find you need more capacity, just add another battery.

A couple of 70 Ah cranking batteries ( total capacity 140 Ah ) should workout a lot cheaper that a single 120 Ah AGM.

Remember, the cheaper batteries are a trade off, they won’t have as long an operating life span but it will still work out about the same price in the long run and by using a few small batteries in the first place, you can then experiment to see what best suits your set up.

Just a rough calculation but 4 x 70 Ah batteries would give you 6 days operation with no sun and would not discharge the batteries below about 60%.


It would take 16 days of sunlight to fully recharge the batteries and operate the pump at the same time.

and I'll back that. As sparky work isnt my specialty area my napkin calcs have a bit more meat on the bone so I get 5 days run and 17 days to charge


as for where to get the batteries, seconds in large battery shops are the way to go as are some call out battery vans.

[drivesafe]

dead flat on the ground with no shade you can pull about 9 hours worth of full power out of a panel in the summer and 6 during winter.

Yep, slightly tilled to face north but no tracking.

The tests I’ve done gets on average roughly 3 amperes an hour, for an average of 8 hours a day from an 80w panel.

BTW, Dave’s 80w panels seem like a good price.

I’ve had my 80w panels for a good few years now but that’s half what I paid.


Dave's Interesting Things - 80 Watt Mono Solar Panel (http://www.davesitshop.com/davesitshop/index.php?_a=viewProd&productId=69)


If solar panel prices keep going down, and our electricity bills keep going up, it won’t be long before solar will be a cheaper option.

[DeanoH]

Why are you going solar and not off the mains? Too far fom the supply? For a $400 ? panel plus bits you can dig a long shallow ditch in the yard a lot cheaper instead.

Deano:)

[Ranga]

Why are you going solar and not off the mains? Too far fom the supply? For a $400 ? panel plus bits you can dig a long shallow ditch in the yard a lot cheaper instead.

Deano:)

Too far from mains, and I'm buying panels for camping anyway, so that way I get to use them all year, not just when camping!

[Ranga]

Dave's Interesting Things - 80 Watt Mono Solar Panel (http://www.davesitshop.com/davesitshop/index.php?_a=viewProd&productId=69)

PM sent!

[d2dave]

If you want cheap solar panels these are the cheapest I have seen.

80watt $337 and 10% discount for AULRO members.

Solar Steve (http://www.solarsteve1950.com/)

Dave.