Trojan 6 volt batteries ruined?

[grafozz]

Due to the lockdown issues I had not been down to the boat for 1 month +, when I did manage to get there , I found the 4x 105 6 volt batteries were showing around 2- 3 volts ,
they are in series for a 12 v system on board .
I have slowly recharged them up and they are at 1270+ now , after 2 days rest .

My question is , have they been irreversibly damaged by this low voltage event ?

I would usually see them up at 13.5 / 14 volts after full charge but now they will only reach 1270+
Batteries are 5 years old and always on charge from 300 watts of solar panels .

 

[pvb]

Due to the lockdown issues I had not been down to the boat for 1 month +, when I did manage to get there , I found the 4x 105 6 volt batteries were showing around 2- 3 volts ,
they are in series for a 12 v system on board .
I have slowly recharged them up and they are at 1270+ now , after 2 days rest .

My question is , have they been irreversibly damaged by this low voltage event ?

I would usually see them up at 13.5 / 14 volts after full charge but now they will only reach 1270+
Batteries are 5 years old and always on charge from 300 watts of solar panels .

If they're always on charge, how come they'd dropped so much in voltage? Have they lost their electrolyte?

 

[simonfraser]

12.70 at rest once charged possibly not ruined
you'll need to do a discharge test to find outfor sure
wire up something of known / useful amp draw and see what happens

 

[sailaboutvic]

I would had said if your battery was 2/3v they seen better days
A discharge test to 10.5 v will give you a better indication.
My old trajan although they would hold their charge i lost 2/3 of their capacity

 

[Mistroma]

12.70 at rest once charged possibly not ruined
you'll need to do a discharge test to find outfor sure
wire up something of known / useful amp draw and see what happens

Usually 12.78V or similar but 12.7V isn't too bad. Obviously something odd has happened if batteries were left on charge with 300W solar. Even without charging T-105s would only lose less than 16% in a month, probably a lot less as temp. won't be very high at present.

I think that OP should also check the charging system.

1) Is there something wrong with the solar charging system?
2) Is there a large load somewhere due to a short?

I'd want to work out why the voltage was so low.

 

[sailaboutvic]

As I read it the op sId his 6v batteries are in serial 12v and are showing 2/3 v I'm taken that he means his 12v bank is showing 2/3 v
But even so if each 6v battery showing that low a voltages it doesn't sound good to me .

 

[pyrojames]

I'd charge them up, if they sit at 12.7 in a bank they might be OK. However if that is in a 2 series 2 parallel configuration you might be hiding a dead one. I'd disconnect them all and test individually after 24 hours and check the water and density if you can. That will show up a failed one (or more).

 

[William_H]

As said divide them so you have 2 lots of 12v. Charge them as best you can then discharge checking current and time to say 11v. You may find one pair better than the other. You may find one 6v battery drops before the other. Ultimately your batteries must be replaced if they won't do the job you require. ie if they won't start the engine (each pair separately) or they won't give you enough time using them to suit your needs. So don't rush to replace them although at 5 years one might think it near time. ol'will

 

[Bobc]

My Trojan 105s sit at 12.7 once left off charge for a day or so, and they've been like that for the last 9 years, so I doubt there's much wrong with them.

Put a load tester across them, and that'll tell you if they're ok or not.

They're bloody tough batteries and are hard to kill.

 

[RichardS]

I suspect that the batteries will not be ruined in the normal sense of the word so you will be able to continue to use them. However, I also suspect that their longevity will also have been shortened so their charged capacity will decrease n a few years earlier than would otherwise have happened.

Richard

 

[Graham376]

If they're always on charge, how come they'd dropped so much in voltage? Have they lost their electrolyte?

My thoughts as well, how much water did they take?

My Trojans are sometimes left for 2-3 months connected to 320w panels via Victron Smartsolar but I turn absorption down to 14.4v if leaving for extended periods with no load except auto anchor light.

 

[simonfraser]

yeh they def are thirsty

 

[differentroads]

1270 SG? or 12.7v as other posters have mentioned? 2-3V over the 12v system or per battery? I'd guess the latter. Too much guesswork from the sparse info provided for us to be much help imho.

 

[grafozz]

1270 SG? or 12.7v as other posters have mentioned? 2-3V over the 12v system or per battery? I'd guess the latter. Too much guesswork from the sparse info provided for us to be much help imho.

Thanks everyone for the feedback .
some further info ,

Trojans are set up as two separate banks of 2x 6v batteries in series as a 12v supply .
Both have solar panels connected through individual MPPT controllers.
Low voltage / 3 v , was seen as a 12v bank , by both banks .
there was perhaps a week of 0 sunshine so little solar charge , before discovering the very low voltage .
the batteries have now been sat for a week + and are still showing around 12.7volts without being connected ,
they are in my garage.
Water did get just below in some cell plates but have been topped up before charging ,
as Simon said , they are "thirsty " !

As both pairs showed this low voltage when connected in the boat I am now thinking that there is possibly some type of drain occurring ?
they keep the charge on the bench .
In the next few days I will refit them and monitor the voltages

What is the best way to load test them ?

 

[sailaboutvic]

Thanks everyone for the feedback .
some further info ,

Trojans are set up as two separate banks of 2x 6v batteries in series as a 12v supply .
Both have solar panels connected through individual MPPT controllers.
Low voltage / 3 v , was seen as a 12v bank , by both banks .
there was perhaps a week of 0 sunshine so little solar charge , before discovering the very low voltage .
the batteries have now been sat for a week + and are still showing around 12.7volts without being connected ,
they are in my garage.
Water did get just below in some cell plates but have been topped up before charging ,
as Simon said , they are "thirsty " !

As both pairs showed this low voltage when connected in the boat I am now thinking that there is possibly some type of drain occurring ?
they keep the charge on the bench .
In the next few days I will refit them and monitor the voltages

What is the best way to load test them ?

If you research back about 18 month you will find how I checked the capacity on my Trojan .
Mine held their charge and worked fine, I charged mine and left them for a week and they never drop ,
but when I did a capicity test I found they lost two third of their capicity .
I was always lead to believe if you fully charge batteries and left them standing over time and they kept their voltage up they fine ,
Now I know all that means is there not a duff cell ,

Just to give you a quick run down , what I did was fully charge the batteries , let them stand a few hours , then I put a 20A load , when the voltages got to 10.5v I checked how many Amps used ,
Others may have a better ways .
Not sure by just putting a load tester on them going to tell you much regarding capicity.

 

[simonfraser]

load test them with a load that you are likely to put on them, they just need to be fit for purpose
if they power your LED anchor light for a week and that is all you need them to do you're ok
on the other hand if they need to run your fridge 24/7 put that on and see what happens over the time interval that you need

 

[RichardS]

Thanks everyone for the feedback .
some further info ,

Trojans are set up as two separate banks of 2x 6v batteries in series as a 12v supply .
Both have solar panels connected through individual MPPT controllers.
Low voltage / 3 v , was seen as a 12v bank , by both banks .
there was perhaps a week of 0 sunshine so little solar charge , before discovering the very low voltage .
the batteries have now been sat for a week + and are still showing around 12.7volts without being connected ,
they are in my garage.
Water did get just below in some cell plates but have been topped up before charging ,
as Simon said , they are "thirsty " !

As both pairs showed this low voltage when connected in the boat I am now thinking that there is possibly some type of drain occurring ?
they keep the charge on the bench .
In the next few days I will refit them and monitor the voltages

What is the best way to load test them ?

The simplest way to test for a current drain is to connect up one terminal of the battery bank to the boat, make sure that everything is turned off as when you would leave the boat, and the connect the other terminal through a multimeter set on the 10 amp (or highest) range and the other side of the multimeter to the boat. If you get a zero or very small reading on the highest amp range, switch the multimeter to a lower range.

If you end up with a zero reading on a low amp range then there is no drain through the boat systems when everything is turned off. If you end up with reading you can use that to calculate roughly how long it would take to flatten the batteries and also start the process of discovering the source of the power drain.

Richard

 

[vas]

grafozz,

a good sign of buggered/dried T105s is that they sort of baloon both along the long sides but surprisingly on the short sides as well! I'm talking about getting off shape by almost 10mm, clearly visible.
Mine have after stupidly letting them for two+ summer months year before run with 600W solar and no topping up. Add to that the earlier firmware from Victron that was a bit more aggressive and things are not that good now.
Still I guess for Med summer and two 80lt fridges I'm doing fine as I can run all things OKish, just V drop late at night to 23.6 or so (with 1-2A loads).
Mid day with the panels pumping I can even run my 2KW watermaker for 30-45mins dragging them down to 22V for 15mins and letting them recover during the afternoon.

Do you have a service battery shunt measuring amps consumed? you mention Victron MPPT controller for them, have you checked/upgraded firmware to the latest one?
Are the settings on the firmware matching carefully the T105 specs? you do need to tune them properly imho.
Highly recommend fitting a BMV7** monitor

cheers

V.

 

[Bobc]

Get one of these to load test them

 

[RichardS]

a good sign of buggered/dried T105s is that they sort of baloon both along the long sides but surprisingly on the short sides as well! I'm talking about getting off shape by almost 10mm, clearly visible.

I'm surprised that a wet cell array which is open to atmospheric pressure would ever be able push out the sides although, from personal experience with a different brand, I know that a blocked vent will do that without fail. I wonder what the mechanism is with the Trojans?

Richard