Still looking? You don't mention capacity.

I have a pair of gel 12V 120Ah (might even be 150Ah - I'll check tomorrow). They were retired as part of scheduled maintenance program on a launch. I may be willing to part with them as they're surplus to requirements. I used them briefly for a powering a LiPo battery 4x 100W field charger. They've been maintained monthly by regular charging since I've had them.

I'm in West Auckland.

Yeah I am always on the lookout.

If you do decide to part with them do you have a price in mind? I see you are in auckland, I forgot to mention I live in Cambridge so anything in the Waikato region would be best for easy pick up.

@jeffnz may be able to help.

cadman:

 

Still looking? You don't mention capacity.

 

I have a pair of gel 12V 120Ah (might even be 150Ah - I'll check tomorrow). They were retired as part of scheduled maintenance program on a launch. I may be willing to part with them as they're surplus to requirements. I used them briefly for a powering a LiPo battery 4x 100W field charger. They've been maintained monthly by regular charging since I've had them.

 

I'm in West Auckland.

 

"Scheduled maintenance" and retirement of Deep Cycle batteries happens after 5 years. Manufacturer warrant those for 10 years. I have tested recently a bulk of retired 5 year old ones under the 25A load. Design capacity - 144AH - Tested capacity - about 63AH.

Regardless of how well you maintain them capacity drops with age. 

Age is far less important in retention of capacity than depth of discharge cycles.

Turns out they are 150Ah.

PM me an offer and if it's agreeable I'll go further with determining if the capacity meets your criteria.

cadman:

 

Age is far less important in retention of capacity than depth of discharge cycles.

 

Turns out they are 150Ah.

 

......

 

- First statement is not correct;

- Second I am 100% confident is "labelled", or "designed" capacity and NOT actual "Remaining Capacity" or "Full Charge Capacity" of a particular battery.

RUKI:

 

cadman:

 

Age is far less important in retention of capacity than depth of discharge cycles.

 

Turns out they are 150Ah.

 

......

 

 

- First statement is not correct;

 

- Second I am 100% confident is "labelled", or "designed" capacity and NOT actual "Remaining Capacity" or "Full Charge Capacity" of a particular battery.

 

 

 

I would agree with his first statement as the deeper the discharge the less life a battery will have, if a battery is only discharging to 80% and well maintained it will last longer than one that is constantly discharged below 50%. I'm not an electrical engineer nor do I spec systemsso could be wrong in this but it is what we are told by manufacturers.

Depending on its uses capacity isn't the measure of a deep cycle battery its run time, standby applications for instance are designed to provide x amount of time if power is interrupted therefore amp's per hour is important in measuring this as they sit there in constant state of charge never needing to cycle. Cycling batteries on the other hand are used in applications that have a constant draw therefore it is important to calculate the depth of discharge and the amount of time they can run before needing charged.

Hopefully I am understanding the conversation, if not I apologise :)

bonkas:

 

Yeah I am always on the lookout.

 

If you do decide to part with them do you have a price in mind? I see you are in auckland, I forgot to mention I live in Cambridge so anything in the Waikato region would be best for easy pick up.

 

PM me your requirements as we always have batteries lying around and we have a branch in Hamilton.

jeffnz: 

 

Depending on its uses capacity isn't the measure of a deep cycle battery its run time, standby applications for instance are designed to provide x amount of time....

 

That sentence is self-contradictory :-)

Take by example those batteries used in Telco network (e.g. cabinets) - those are sitting there with the purpose - to provide back up in case of power failure constantly "trickle charged". According to maintenance schedule load tests are run from time to time. However - in 5 years capacity drops more than 1/2 and hence they unable to provide expected run time to support telco network and hence replaced.

When I make statements - those are from practical experience, supported by captured data, cross referenced to datasheets I have in my DB.

RUKI:

 

cadman:

 

Age is far less important in retention of capacity than depth of discharge cycles.

 

Turns out they are 150Ah.

 

......

 

 

- First statement is not correct;

 

- Second I am 100% confident is "labelled", or "designed" capacity and NOT actual "Remaining Capacity" or "Full Charge Capacity" of a particular battery.

 

 

 

First statement is absolutely correct. Shallow discharge bodes for a much longer useful life.

And I never claimed that their capacity now is as labelled. I don't think anyone is under any illusion that these batteries are as-new, are they?

EDIT: I should have mentioned that these particular batteries were charged both by the boat's engine charging system and by a wind generator and from shore power when at the marina.

RUKI:

 

jeffnz: 

 

Depending on its uses capacity isn't the measure of a deep cycle battery its run time, standby applications for instance are designed to provide x amount of time....

 

 

That sentence is self-contradictory :-)

 

Take by example those batteries used in Telco network (e.g. cabinets) - those are sitting there with the purpose - to provide back up in case of power failure constantly "trickle charged". According to maintenance schedule load tests are run from time to time. However - in 5 years capacity drops more than 1/2 and hence they unable to provide expected run time to support telco network and hence replaced.

 

When I make statements - those are from practical experience, supported by captured data, cross referenced to datasheets I have in my DB.

 

 

 

I expect they're also sized to allow for an particular outage duration with little reserve capacity beyond that so when they do come online, they're quickly depleated to a considerable depth - both heavily weighted factors in battery durability.

The capacity is based on a 20 hour discharge. So 150Ah/20 is 7.5A for 20 hours. Go over that draw and they're quickly derated. Correct me if I'm wrong but I can't see telcos anticipating a 20 hour outage so I doubt they size their backup supply for that so I'd expect they'd be minimising cost and going for smaller capacity to cover shorter durations at full power.

RUKI:

 

jeffnz: 

 

Depending on its uses capacity isn't the measure of a deep cycle battery its run time, standby applications for instance are designed to provide x amount of time....

 

 

That sentence is self-contradictory :-)

 

Take by example those batteries used in Telco network (e.g. cabinets) - those are sitting there with the purpose - to provide back up in case of power failure constantly "trickle charged". According to maintenance schedule load tests are run from time to time. However - in 5 years capacity drops more than 1/2 and hence they unable to provide expected run time to support telco network and hence replaced.

 

When I make statements - those are from practical experience, supported by captured data, cross referenced to datasheets I have in my DB.

 

 

 

What you are talking about are not deep cycle batteries, they aren't designed to cycle. The OP is talking about deep cycle so maybe we should get the thread back on topic.

jeffnz:

 

What you are talking about are not deep cycle batteries, they aren't designed to cycle. The OP is talking about deep cycle so maybe we should get the thread back on topic.

 

I am dropping off this at this stage. I know exactly what I am talking about... I've spent over 30 years in Telco with 13 years of that in New Zealand Telco. For obvious reasons I can not mention here MOP & SOW reference numbers and part numbers of DEEP CYCLE batteries used ... (can't disclose..) . Good luck.. If you need to test whatever batteries you might find around - give me a buz...

RUKI:

 

jeffnz:

 

What you are talking about are not deep cycle batteries, they aren't designed to cycle. The OP is talking about deep cycle so maybe we should get the thread back on topic.

 

 

I am dropping off this at this stage. I know exactly what I am talking about... I've spent over 30 years in Telco with 13 years of that in New Zealand Telco. For obvious reasons I can not mention here MOP & SOW reference numbers and part numbers of DEEP CYCLE batteries used ... (can't disclose..) . Good luck.. If you need to test whatever batteries you might find around - give me a buz...

 

Don't be like that. I'm interested in hearing what you have to say but context should be taken into account.

All I'm saying is that just because the batteries in the service you have experience with might well have only 50% of their original rated capacity after 5 years doesn't mean all batteries will be the same. That level of durability may be all they're aiming for with a particular installation for whatever reasons.

I am after something/multiple in the vicinity of 80-100ah (of course larger is always better!)

This is for a small electronic project so looking for low cost used options.