Trojan batteries supplied at 50% charge - worrying?

[mattcyp]

As a long time lurker I've finally not been able to find an answer here so thought i'd start my own thread.

 

I recently purchased 6 trojan 27tmxs (an alteration to the battery boxes to take the recomended t105s just isn't possible at the moment) for a leisure bank and was a little suprised when they arrived with a teminal pd of 12.2v. Given a good charge (sterling combi) up to 14.7v until the current tailed off to ~5 amps all seemed well and I then set about letting them discharge through their first cycle.

 

After 330ah had been taken off over a couple of days (measured with a vectron bmv 600 - the bank is just over 600ah stated capacity) the terminal pds were looking poor so I let them stand for 4 hours to check them out further. To my dismay they showed a rested pd of 11.8v and a specific gravity of just over 1.12, which I interpreted as them being pretty much flat.

 

So, to the expertise of the forumn - If I draw off 300ah from a quality (trojan) 600ah battery bank, I should only see the soc dropping to around 50%, not the near 0% I saw?

Secondly, is it bad for batteries to stand for months (in the warehouse, I assume) at such a low state of charge as was indicated by the voltage I measured when they were delivered?

 

Thanks in advance for any ideas on this!

Edited February 4, 2015 by mattcyp

[dmr]

Can you find a date stamp somewhere on the batteries? If so you should find how to "decode" it somewhere on the www..

Batteries do discharge themselves over time but this is very temperature dependant.

As they may have a hint of sulphation I would charge them at at least 14.8 volts, and maybe do an initial 15.5 volt equalisation charge.

I would also check the specific gravity with a hydrometer.

 

...........Dave

[mattcyp]

Thanks for the suggestions. They were manufactured in april 2014.

Doing an equalisation charge sounds like a good idea, though the disparity between the stated capacity and what I'm getting seems too large for that to have the major effect required?

 

I haven't checked the specific gravity when charged - only when 330 ah had been drawn out.

 

 

[nicknorman]

Regarding storage, Trojan recommend recharging when they get down to 70% SoC, checking every 4-6 weeks. I would suggest this hasn't been done by the supplier. Since your batteries are a relatively uncommon variety, I guess the turnover at the retailer has been slow.

 

Anyway, I would flag this issue up with the supplier now. Depending on how hard it is, you could contemplate returning them, but of course they may supply you with new batteries that were in the same state until they recharged them today. Alternatively you could give them a good charge plus equalisation (until the SGs stop rising) and they will probably be fine.

 

In my case when I got a new set of T105s, even though they appeared well charged, they were very reluctant to both take and give charge. I would say that my first cycle only gave about 50% capacity. However, after about 5 deep cycles they were absolutely fine and remain at full capacity after a year. So perhaps flag the issue up straight away, but then try a few deep cycles before deciding if they are damaged and whether you want to return them.

Edited February 4, 2015 by nicknorman

[mattcyp]

Thanks for this input. Your comments on T105's being slow to get in to their stride is consoling.

 

I'll give them a good charge (equalisation) and see if that improves things.

After a bit of a fight the supplier has since confirmed that the entire batch showed low pds (12.2v) and are being returned to the importer for testing so perhaps there is something wrong with them.

[cereal tiller]

Thanks for this input. Your comments on T105's being slow to get in to their stride is consoling.

 

I'll give them a good charge (equalisation) and see if that improves things.

 

After a bit of a fight the supplier has since confirmed that the entire batch showed low pds (12.2v) and are being returned to the importer for testing so perhaps there is something wrong with them.

I bought 3 Trojan TMX's June 2014,checked Voltage as soon as they were delivered .it was 12.6/12.7 average.

 

The 2 previous sets of batteries which were Numax and Powerbatt failed to deliver rated capacity from new,

 

The Trojans have performed faultlessly thus far,will get 3 more to increase bank size.

CT

[mattcyp]

CT, thanks ofr this input. What are you using to measure the capacity?

[cereal tiller]

CT, thanks ofr this input. What are you using to measure the capacity?

Digital shunt ammeter and 5 digit Volmeters which have a dedicated supply from master switch with an inline fuse.3 Voltmeters in total placed around the boat, one on engine instrument panel,one in main saloon and the third

one on bulkhead at foot of bed.No battery power is drawn overnight as the Inverter is turned off and the boat has a gas fridge

 

So after 7-8 hours rest the indicated voltage gives a good indication of S.O.C.

I confess to being a 'Battery Gazer'

 

CT

CT

[dmr]

Digital shunt ammeter and 5 digit Volmeters which have a dedicated supply from master switch with an inline fuse.3 Voltmeters in total placed around the boat, one on engine instrument panel,one in main saloon and the third

one on bulkhead at foot of bed.No battery power is drawn overnight as the Inverter is turned off and the boat has a gas fridge

 

So after 7-8 hours rest the indicated voltage gives a good indication of S.O.C.

I confess to being a 'Battery Gazer'

 

CT

CT

 

A voltmeter in the bedroom, that's serious stuff. Are you worrying about your batteries a bit too much?.

 

We sleep in the backcabin so I can just about see the ammeter in the engine room from my bed, but I have to sit up to get a line of sight to the Smartgage.!!!!!

 

...............Dave

[cereal tiller]

 

A voltmeter in the bedroom, that's serious stuff. Are you worrying about your batteries a bit too much?.

 

We sleep in the backcabin so I can just about see the ammeter in the engine room from my bed, but I have to sit up to get a line of sight to the Smartgage.!!!!!

 

...............Dave

Moi,O.C.D.?Surely not!

 

The nice thing about the one that can be seen from the Bed is that one knows when it is Dawn,so satisfying to watch the Voltage ascend once the Solar Panels become active.

 

CT

[mattcyp]

So after 7-8 hours rest the indicated voltage gives a good indication of S.O.C.

I confess to being a 'Battery Gazer'

 

 

That's a nice way to do it. Sadly I've got an electric fridge which stops the voltages settling too much.

 

Solar is always very satisfying too!

 

 

Incidentally, how long would you recomend for a good equalisation charge?

 

It owuld be done with a sterling pro combi connected either to shoreline (if the current ice melts) or perhaps a generator.

[dmr]

 

That's a nice way to do it. Sadly I've got an electric fridge which stops the voltages settling too much.

 

Solar is always very satisfying too!

 

 

Incidentally, how long would you recomend for a good equalisation charge?

 

It owuld be done with a sterling pro combi connected either to shoreline (if the current ice melts) or perhaps a generator.

 

The standard method is to measure the specific gravity every hour and to continue till the specific gravity is no longer increasing, or when the batteries get too hot. Several hours in some cases.

 

..............Dave

[nicknorman]

Incidentally, how long would you recomend for a good equalisation charge?

 

It owuld be done with a sterling pro combi connected either to shoreline (if the current ice melts) or perhaps a generator.

 

You really need a hydrometer (the refractometer ones from eBay are really easy to use, and accurate). You then fully charge the batteries as normal, only once they are fully charged do you increase to 15.5v. Then monitor the SG every hour and stop the EQ when the SG stops increasing. However my suggestion would be to give them a good few normal cycles first (fully charging each time) to see if they settle down on their own.

[forsberg]

 

Incidentally, how long would you recomend for a good equalisation charge?

4 hours to 3 days in worst case.

Use of a hydrometer to check each cell will tell when done (and also if at all neccesary/ being the issue).

Alterative disconnet bridge and mesure volt on each battery after 1h rest.

It will also indicate if any of the batteries stand out and you could give it some special attention.

Just note that SOC is logarithmic and hydroweight is linear, so no need to fret if you dont get green readings first cycle.

You should disharge to at lest 80 SOC between equalisations if you do it more then once.

 

 

[trackman]

Matt I have sent you a pm. I recently acquired the same type of Trojans and your posts are concerning me!

[smileypete]

 

The standard method is to measure the specific gravity every hour and to continue till the specific gravity is no longer increasing, or when the batteries get too hot. Several hours in some cases.

 

ISTR US Battery recommend the eq. current is limited, to something like C/30.

 

If your batts tend to get a bit sulphated, an online seller Courtiestown Marine does decent kits at reasonable prices last time I looked.

 

cheers, Pete.

~smpt~

Edited February 6, 2015 by smileypete

[Loafer]

 

ISTR US Battery recommend the eq. current is limited, to something like C/30.

 

If your batts tend to get a bit sulphated, an online seller Courtiestown Marine does decent kits at reasonable prices last time I looked.

 

cheers, Pete.

~smpt~

 

My Victron limits it's charging current when equalising. To about 12A or so. If that's not enough to maintain Eq voltage, it drops back into Absorb at 14.8V until you intervene again a bit later. Once able to sustain Eq voltage with it's limited current, off it goes then for 2 hrs.

[mattcyp]

Thanks to all the info on this thread (and sorry for the slow reply). After about half a dozen cycles and 3 or 4 equalisation charges the batteries perked up significantly and are now working well.