Failure of Trojan batteries after 2 years and 9 months

pvb said:
But you had T105s, which are known to have longer lives than Trojan's 12v batteries. The OP has Trojan 12v batteries.
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True these are about 600 cycles to 50%DOD rather than 1200 for the T105 which don't fit easily. However have had much less than 100 cycles less than 80%

The Victron stuff is supposed to be able to take external control but does not seem to work well when I have tried to implement it. I think I agree that the best way to proceed is to disconnect solar when on shore power.
 
pvb said:
But you had T105s, which are known to have longer lives than Trojan's 12v batteries. The OP has Trojan 12v batteries.
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Yes he did, I should have made it clearer, although I did say the T105 were 6v.

In fact eventually I had a combination of T105 and 12v (not trojan 12v) amounting to some 700Ah not including the starter.

We have had this discussion re solar chargers previously, it could be possibly the cause of the problem, but I have and still advocate fitting the more expensive controllers of reputable make in preference to others.
An extra 40 to 50 £'s is well worth paying, if, and I repeat if, the PO's problem was caused by a controller. There is currently, no pun intended, evidence it was a controller.
 
Providing the controller is a good one there is no reason why solar and mains are incompatible, one will not effect the other, that has been my personal experience with some
400w of solar in Greece, as you will know a very sunny place.
 
Freedom35 said:
... There is currently, no pun intended, evidence it was a controller.
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If the battery hs been overcharged, the controller is not doing the job.
That's not to say the controller isn't brilliant at doing the job is was intended for.
Whih probably wasn't closely related to storage mode on a yacht not really in commission.
 
So presumably if you have both shore power charger and solar chargers connected the following has occurred. The shore power goes through its normal charging process when first connected and brings the batteries up to fully charged then sits them in float. They would stay like this for weeks or months with out a problem. If you then have solar charging, each morning the solar charger boots up, sees a float voltage then as the sun rises in the sky, it starts to charge the batteries to their absorption voltage. Once at their absorption voltage the solar charger hold the batteries at this elevated voltage for a few hours then drops them back to float. It does this every day needlessly as the shore power charger has already charged them and is holding them in a state of charge. Consequences are serious over charging and warped plates. Depending on how the batteries are wired together, it is likely that the first battery to fail will be the one closest to the positive terminal with the lowest resistance and hence seeing the highest voltage.
Never run shore power and a large PV installation at the same time if you want to look after your batteries. No battery whether its open cell, AGM or gel likes being overcharged.
 
DuncanHall said:
Paul I did in #1

Its remote monitored on and can be seen on Victron connect. Thats how I spotted the failure as the current increased and the battery temperature rose.
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Sorry, missed the mention of Venus. So, you have been monitoring the solar controller ? You should be able to see how long it's been on absorption and what the max voltages have been. You can also check the controller settings to ensure the output voltages are correct. Should help identify what went wrong.

As only one battery failed it's also quite possible (even likely), that you had a faulty battery. If it was an over charging issue, you'd expect all three to fail together.
 
geem said:
So presumably if you have both shore power charger and solar chargers connected the following has occurred. The shore power goes through its normal charging process when first connected and brings the batteries up to fully charged then sits them in float. They would stay like this for weeks or months with out a problem. If you then have solar charging, each morning the solar charger boots up, sees a float voltage then as the sun rises in the sky, it starts to charge the batteries to their absorption voltage. Once at their absorption voltage the solar charger hold the batteries at this elevated voltage for a few hours then drops them back to float. It does this every day needlessly as the shore power charger has already charged them and is holding them in a state of charge. Consequences are serious over charging and warped plates. Depending on how the batteries are wired together, it is likely that the first battery to fail will be the one closest to the positive terminal with the lowest resistance and hence seeing the highest voltage.
Never run shore power and a large PV installation at the same time if you want to look after your batteries. No battery whether its open cell, AGM or gel likes being overcharged.
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Sorry, but that's all totally incorrect. The Victron controller will not behave as you have described, if the mains charger is on. It's smart enough to know the batteries are charged and it will not over charge the batteries as you describe.
 
PaulRainbow said:
Sorry, but that's all totally incorrect. The Victron controller will not behave as you have described, if the mains charger is on. It's smart enough to know the batteries are charged and it will not over charge the batteries as you describe.
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The OP states he has MPPT 75/15. Does he state that his shore power charger has an interface to the MPPT 75/15? I didnt see any mention of this in his post. The MPPT solar charger on its own is not sophisticated enough to know the shore power is on and working. The MPPTs only control is seeing the elevated voltage on the batteries each morning and reducing the absorption time.
 
geem said:
The OP states he has MPPT 75/15. Does he state that his shore power charger has an interface to the MPPT 75/15? I didnt see any mention of this in his post. The MPPT solar charger on its own is not sophisticated enough to know the shore power is on and working. The MPPTs only control is seeing the elevated voltage on the batteries each morning and reducing the absorption time.
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The Victron MPPT, BMV 700 and the multiplus are interconnected via a Raspbery Pi runningVenus OS connected via USB. T MPPT does attempt to get to absorption each day. However due to the limited solar it does not get to absorption.

For instance on 25th August it achieved 14.4V and 4.2A net to battery. Battery temperature was 24C

I recall that a year earlier it did get to absorption indicating perhaps as the batteries aged that they took more current.

Looking back to the end of June when the boat was unattended and on charge I was typically getting up to 5.5 A into the batteries but never attained absorption here The battery temperature was between 20 and 22 C
 
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DuncanHall said:
The Victron MPPT, BMV 700 and the multiplus are interconnected via a Raspbery Pi runningVenus OS connected via USB. T MPPT does attempt to get to absorption each day. However due to the limited solar it does not get to absorption.

For instance on 25th August it achieved 14.4V and 4.2A net to battery. Battery temperature was 24C

I recall that a year earlier it did get to absorption indicating perhaps as the batteries aged that they took more current.

Looking back to the end of June when the boat was unattended and on charge I was typically getting up to 5.5 A into the batteries but never attained absorption here The battery temperature was between 20 and 22 C
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I think you have a strange idea of what absorption is all about.
Your batteries are full.
They need a few mA at 13.6V or so to counter any self discharge.
You are shoving in 4 or 5 amps and wondering why they're now broken.
 
lw395 said:
I think you have a strange idea of what absorption is all about.
Your batteries are full.
They need a few mA at 13.6V or so to counter any self discharge.
You are shoving in 4 or 5 amps and wondering why they're now broken.
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Sir

I understand perfectly well what Absorption is. It is not I that am putting in 4 or 5 A but the controller.

Reading Victrons Manual it states

"3.8 Battery charging information
The charge controller starts a new charge cycle every morning, when the sun starts shining.
Lead-acid batteries: default method to determine length and end of absorption
The charging algorithm behavior of MPPTs differs from AC connected battery chargers.
Please read this section of the manual carefully to understand MPPT behavior, and always
follow the recommendations of your battery manufacturer.
By default, the absorption time is determined on idle battery voltage at the start of each day
based on the following table:
EN NL FR DE ES SE Appendix
Battery voltage Vb (@start-up) Multiplier Maximum absorption time
Vb < 11,9V x 1 6h
11,9V < Vb < 12,2V x 2/3 4h
12,2V < Vb < 12,6V x 1/3 2h
Vb > 12,6V x 1/6 1h
(12V values, adjust for 24V))
Default absorption voltage: 14,4V"

On seeing 13.2 V it seeks to go into bulk mode first but never gets to absorption as it does not achieve the absorption voltage. For example on the 25th August It set itself at the bulk mode from 6am to 6pm

All the systems components are using the latest firmware and the voltages are set to Trojans recommended values.
 
Running a shore charger and the Victron MPPT controllers at the same time on batteries that have little discharge will result in overcharging on the default values. This is easily fixed, the Victron controllers are very adjustable. If leaving the boat with little draw when it is connected to shore charger the parameters should be changed to be appropriate for this storage mode.

One thing to watch is new Victron software (1.42) very radically alters how the controllers work. The new charging algorithm is better but it significantly increases the chances of overcharging if the default values are unchanged. In particular the way the absorption and equalisation time is measured is very different following the software update. This results in most circumstances in a much longer absorption and equalisation time.
 
geem said:
The OP states he has MPPT 75/15. Does he state that his shore power charger has an interface to the MPPT 75/15? I didnt see any mention of this in his post. The MPPT solar charger on its own is not sophisticated enough to know the shore power is on and working. The MPPTs only control is seeing the elevated voltage on the batteries each morning and reducing the absorption time.
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They don't need to be interfaced. When the solar controller starts in the morning and the battery voltage is at float voltage, it's not too difficult to know what's going on. The Victron controller will not overcharge the batteries just because the mains charger has been on, on the contrary, if the mains charger is on, there is negligible output from the controller. If your theory was correct, every boat that has the mains charger on and solar fitted would have fried batteries.
 
lw395 said:
I think you have a strange idea of what absorption is all about.
Your batteries are full.
They need a few mA at 13.6V or so to counter any self discharge.
You are shoving in 4 or 5 amps and wondering why they're now broken.
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How do you "shove" 4 or 5 amps into fully charged batteries ?
 
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