Best batteries?

[Gibbo]

Hows this little experiment going?

 

They are Hawker 12FV120 AGMs.

 

I've never seen them for sale anywhere. These are from the MOD.

 

I'm having a bit of trouble breaking them

[Justme]

Sound good, but I guess costly

 

http://www.army-technology.com/contractors/electrical/enersys/

[badgerburger]

They are Hawker 12FV120 AGMs.

 

I've never seen them for sale anywhere. These are from the MOD.

 

I'm having a bit of trouble breaking them

 

I'd be very interested to know how this goes. We've got Hawker AGMs (though not that exact model) in our boat. I've been trying hard to break them for several years now ...

 

B.B.

[Gibbo]

Quick update.

 

The brand new Hawker battery started off, on the first discharge following an initial charge, at 120 ahrs. After a few cycles it was up to 130 ahrs (it's rated at 110!).

 

It has now had 25 cycles with each discharge going down to a terminal voltage of 10.5 volts (ie as flat as a pancake).

 

The capacity is still at 130 amp.hours. Remarkable.

[DHutch]

We bought some fairly middle of the road Exides last time, 7 years a go i beleave, and they are just about up for renewal. They arent used hard, but the nature of a steam engine means occationally they are used for a week without decent recharge (genny to top up sometimes, sometimes not )and get a bit low but generally well looked after.

 

I have heard comments suggesting wet lesure batterys might be getting harder to get hold off, but assuming there some around in march this will be our plan again.

 

If you are going for the 'cheap and cheery, replace them often' then £25 for even a used 110ah battery isnt a bad price.

 

 

 

Daniel

 

i wasnt, warm beer and the risk of food poisoning from warm meat, no thanks

We turn our fridge off over night, partly for elec reasons, mainly for noise reasons, and have never risked warm beer.

- Throughout the day it runs for about 60-80% of the time turned down to max then during the night it coasts on the 6 freezer blocks in the ice box at the top.

 

 

Daniel

[Pretty Funked Up]

Quick update.

 

The brand new Hawker battery started off, on the first discharge following an initial charge, at 120 ahrs. After a few cycles it was up to 130 ahrs (it's rated at 110!).

 

It has now had 25 cycles with each discharge going down to a terminal voltage of 10.5 volts (ie as flat as a pancake).

 

The capacity is still at 130 amp.hours. Remarkable.

 

They might be rated at 110Ah on the 20hr rate, so 130Ah would easily be feasable on the 100hr rate.

 

I've just picked up 2 hawker SBS C11's (92Ah). The guy had 6 of em for sale and by the sounds of the above I'm going to be kicking myself for not getting all 6

Edited December 16, 2010 by Pretty Funked Up

[nb Innisfree]

They might be rated at 110Ah on the 20hr rate, so 130Ah would easily be feasable on the 100hr rate.

 

I've just picked up 2 hawker SBS C11's (92Ah). The guy had 6 of em for sale and by the sounds of the above I'm going to be kicking myself for not getting all 6

 

I assumed that Gibbo meant an advertised 110 ah@20hr but 130 ah@ 20 hr was achieved?

[Robin2]

I think this is as good a place as any to ask this question...

 

Manufacturers talk of batteries surviving for X cycles at Y depth of discharge etc. But what is a single battery cycle?

 

This is not a trivial question.

 

For example a cycle could be from one time at full charge to the next time at full charge - perhaps with a period of several days in between when the battery was partially discharged and partially charged.

 

Or it might be from the low of one discharge to the low of the next one - eg discharge to 50% last night, charge to 65% this morning and discharge to 55% this afternoon before a longer evening charge.

 

Neither of these seems to me to be a reasonable definition.

 

So what is the correct definition?

[nb Innisfree]

I think this is as good a place as any to ask this question...

 

Manufacturers talk of batteries surviving for X cycles at Y depth of discharge etc. But what is a single battery cycle?

 

This is not a trivial question.

 

For example a cycle could be from one time at full charge to the next time at full charge - perhaps with a period of several days in between when the battery was partially discharged and partially charged.

 

Or it might be from the low of one discharge to the low of the next one - eg discharge to 50% last night, charge to 65% this morning and discharge to 55% this afternoon before a longer evening charge.

 

Neither of these seems to me to be a reasonable definition.

 

So what is the correct definition?

 

Varies, depends on the manufacturers definition, take all claims with a large pinch of salt.

[Pretty Funked Up]

I've always taken a cycle to be from fully charged to the manufacturers recommended DOD.

And the figures are based on it getting immediatley charged back up again.

[Gibbo]

They might be rated at 110Ah on the 20hr rate, so 130Ah would easily be feasable on the 100hr rate.

 

LMAO

 

Considering what I do for a living, it didn't occur to you that this has been taken into consideration and accounted for?

 

 

I think this is as good a place as any to ask this question...

 

Manufacturers talk of batteries surviving for X cycles at Y depth of discharge etc. But what is a single battery cycle?

 

This is not a trivial question.

 

 

It starts fully charged, then is discharged down to the specified DOD, then immediately recharged, then immediately discharged again and so on.

 

They do it at two extremes of a low DOD and a high DOD then interpolate.

[Pretty Funked Up]

LMAO

 

Considering what I do for a living, it didn't occur to you that this has been taken into consideration and accounted for?

 

 

fairy point

 

Hawker seem to advertise Ah based on the 10hr rate.

 

my SBS C11's say 92Ah on em but when i looked into it thats the 10hr rate (didnt say that on label though)

 

So I should've put ...

'They might be rated at 110Ah on the 10hr rate, so 130Ah would easily be feasable on the 20hr rate'

Edited December 17, 2010 by Pretty Funked Up

[Gibbo]

They are rated at 110Ahrs@20hrs. They are rated at 100Ahrs@10hrs.

 

This calculates to a Peukert exponent of 1.16

 

They are actually producing 130ahrs at the 20 hour rate.

[Pretty Funked Up]

Very interesting/good news they are still showing full capacity after 25 killer cycles.

nice1

[smileypete]

They are Hawker 12FV120 AGMs.

 

I've never seen them for sale anywhere. These are from the MOD.

 

I'm having a bit of trouble breaking them

 

Hi Gibbo,

 

Would be interested in more info on the starter batt you tested.

 

Eg make, type, part no?

 

cheers,

Pete.

[Gibbo]

Hi Gibbo,

 

Would be interested in more info on the starter batt you tested.

 

Eg make, type, part no?

 

cheers,

Pete.

 

The one that broke when I sneezed near it with a load in my hand?

[Pretty Funked Up]

The one that broke when I sneezed near it with a load in my hand?

 

Sure theres a joke in that somewhere

[smileypete]

The one that broke when I sneezed near it with a load in my hand?

Yeeeees!

[Nickhlx]

Does a lower Peukert Exponent ( nearer to 1) indicate a high quality battery, or nothing to do with it ?

 

(I notice the Trojans I have are 1.23)

 

 

Nick

[Robin2]

 

It starts fully charged, then is discharged down to the specified DOD, then immediately recharged, then immediately discharged again and so on.

 

 

That's sort of what I imagined. So how do we extrapolate from that rather impractical (and uneconomic) way of using batteries to the real world of the narrowboater? (Whether narrowboaters live in the real world is for another day )

 

If I discharge a battery from 100% to 50% then go to 80% 50% five times before I charge back to 100% how many of the manufacturers cycles have I used? Does the time between recharging matter - for example if the five partial charges that I mentioned are spread over 5 days or 10 days?

[Pretty Funked Up]

If I discharge a battery from 100% to 50% then go to 80% 50% five times before I charge back to 100% how many of the manufacturers cycles have I used?

six

 

Does the time between recharging matter

yes

Edited December 17, 2010 by Pretty Funked Up

[Gibbo]

Sure theres a joke in that somewhere

 

 

I thought that at the time I wrote it.

 

 

Yeeeees!

 

I had to go in the garage to find it. It's a Varta D21 which apparently is 61Ahr and 600CCA.

 

 

Does a lower Peukert Exponent ( nearer to 1) indicate a high quality battery, or nothing to do with it ?

 

It is related but not that simply. The biggest difference is the type (as opposed to quality) of battery. Generally speaking (there are exceptions) AGMs and engine start have the lowest, then gel cells and leisure then deep cycle usually being the worst. But it really is a very rough guide with loads of exceptions.

 

That's sort of what I imagined. So how do we extrapolate from that rather impractical (and uneconomic) way of using batteries to the real world of the narrowboater? (Whether narrowboaters live in the real world is for another day )

 

If I discharge a battery from 100% to 50% then go to 80% 50% five times before I charge back to 100% how many of the manufacturers cycles have I used? Does the time between recharging matter - for example if the five partial charges that I mentioned are spread over 5 days or 10 days?

 

I don't thik there would be any way to even guess at it let alone calculate it.

[Evo]

Interesting stuff...what actually happens to the batteries when they discharge..?? why do some recover so well and others not at all. I'd like to know whats physically/chemically happened inside. Why are they not recoverable, have plates bent and shorted, have they sulphated, if sulphated are they recoverable. I dont understand whats actually happened. has the acid gone..the lead gone. I ask because I have alot of batteries and some maybe recoverable if the right thing is done to them..they are not old but have been left to go flat. They haven't discharged quickly, just slowly over time.

Edited December 17, 2010 by Evo

[Pretty Funked Up]

Interesting stuff... I dont understand whats actually happened. has the acid gone..the lead gone.

 

The available lead and available acid gets locked into lead sulphate crystals.

 

They used to this and still should:

 

A battery you can take apart to clean up the surface of the plates (sand paper or a file doesnt really matter so long as they arent distorted etc.)

[Evo]

Yes I understand some of the process, but I assume all batteries have the same quality of acid so is the only difference the quality of the alloy used for the plates. I understand Charging reverses the process, what makes it fail..??

 

I've got 4 or five batteries on the floor of my garage that when I charge them all cells bubble away and they appear to be charging fine. They are not however and lose any charge very quickly, whats going on there.? The batteries are less than a year old...(they are motorcycle batteries).