Failure of Trojan batteries after 2 years and 9 months

D

DuncanHall

Well-Known Member
Joined
14 Feb 2013
Messages
152
Location
Cardiff Yacht Club
Visit site
I have a domestic battery bank of 3 Trojan 31 XHS batteries purchased February 2016. They are charged by a Victron multiplus at the recommended charging voltages for Trojan batteries with Trojans recommended temperature compensation. Fortuitously I monitor the battery state remotely using a raspberry PI running Victorns Venus software which connects to a Victron BMV 700, the solar charge controller (MPPT 75/15). Last week I noted the current rising and the battery temperature increasing. I went to the boat and found that one of the batteries had failed. Once disconnected from the charger it read under 11V. Fortunately the other pair seem OK reading about 12.8V fully charged with no load after a days rest.

In the remaining batteries the plates are clearly distorted

The boat is not in daily used and has suffered very few deep discharges. It is typically used about 8 weeks per year so the cause of failure is not deep cycling the batteries. The battery bank is used to drive the inverter in the multiplus. When it does this the current is typically up to 100A. Could this be the cause of failure or is something else in my use causing a problem.

Should I persevere with this type of battery or would I be better switching to AGMs.
 
The first question I'd ask, Duncan, is what charging regime applies in the evidently extended periods you are not at the boat? Deep-cycle Trojans have a considerable self-discharge rate. I would personally not consider using them for 8-weeks-in-52 use. (That said, distorted plates do suggest overcharging.)
 
Last edited:
macd said:
The first question I'd ask, Duncan, is what charging regime applies in the evidently extended periods you are not at the boat? Deep-cycle Trojans have a considerable self-discharge rate. I would personally not consider using them for 8-weeks-in-52 use.
Click to expand...

The multiplus on on and it follows Victrons recommended prescription for Trojans, e.g
Ansorbtion 14.82V
Float 13.5
Max charge current 17A per battery
Temp comp -30mV/deg C
Repeated Absorption time 1hr
Repeat Absorption Interval 7 days

Storage mode set which gives 13.2V after 1 day at float.

However the solar panels are not so constrained so that it goes on bulk mode each day
 
Last edited:
Trojan T105's are beloved of the liveabord community.
6v 225Ah.
Two in series and you have 12v and 225Ah
Parallel another series pair and 12v 450Ah
They have long lives, used in go carts which are subjected to heavy discharing and re charging, they thrive on it.
 
Is the mains charger connected when the boat is not in use?

My guess would be that the solar controller has been overcharging, by spending unnecessary time in absorption phase every day.
Possibly you have some small permanent load causing the charger to wrongly assess the state of charge every morning?

I don't think these solar controllers are really designed around the concept of medium term 'mainenance' charging, they are intended for applications like street signs where the battery is loaded every night.
The algorithm they use to decide when to switch to float is optimised around that concept from what I can undertand. That's why they have a pair of terminals labelled 'load'.

Frmom the remote monitoring, can you see how much current was going in every day, for how long?
 
Freedom35 said:
Trojan T105's are beloved of the liveabord community.
6v 225Ah.
Two in series and you have 12v and 225Ah
Parallel another series pair and 12v 450Ah
They have long lives, used in go carts which are subjected to heavy discharing and re charging, they thrive on it.
Click to expand...


Yes, Trojan's own figures confirm that their 12V range will usually only manage about 50% of the cycles managed by the 6V range. T105s usually work out much better value than their 12V range as price difference isn't very great and you can reasonably expect twice the lifespan. Only problem is fitting them into some battery boxes, I re-built mine to handle them.

OP isn't deep cycling so I suspect overcharging is more to blame than repeated deep cycling.
 
Last edited:
Freedom35 said:
Trojan T105's are beloved of the liveabord community.
6v 225Ah.
Two in series and you have 12v and 225Ah
Parallel another series pair and 12v 450Ah
They have long lives, used in go carts which are subjected to heavy discharing and re charging, they thrive on it.
Click to expand...

That might be useful if the OP had T105s
 
Had a sailing boat in Southwold that has the same sort of batteries and his solar over the summer had basically dried the batteries out, ruined the plates. Only apparent when we went to move the boat on his instruction to find the batteries egging up a treat, all cells very dry!

They are actually very good batteries but need looking after. I find this doesn't happen if the batteries are in an awkward place to get to or if people are the "just want to go boating" type.

My own boat uses Victron AGM's because they're buried and difficult to get to so no chance of maintenance.


simonfraser said:
they use a lot of water, did they dry out ?
Click to expand...
 
lw395 said:
Is the mains charger connected when the boat is not in use?

My guess would be that the solar controller has been overcharging, by spending unnecessary time in absorption phase every day.
Possibly you have some small permanent load causing the charger to wrongly assess the state of charge every morning?

I don't think these solar controllers are really designed around the concept of medium term 'mainenance' charging, they are intended for applications like street signs where the battery is loaded every night.
The algorithm they use to decide when to switch to float is optimised around that concept from what I can undertand. That's why they have a pair of terminals labelled 'load'.

Frmom the remote monitoring, can you see how much current was going in every day, for how long?
Click to expand...

Yes mains charger on when not in use but has Victron recommended configuration.

There is only about 200W solar on deck in partial shade which in Sept for example raised voltage to about 14.5V so did not get to absorption on the solar controller. The net current was typically 3A compared to the storage current of 0.2 A for the bank.

Over winter I leave the mains on since it is used to run the dehumidifier. I wonder whether the best course of action is to turn the bulk voltage down to 13.2 on the solar system when connected to the grid.
 
lw395 said:
I don't think these solar controllers are really designed around the concept of medium term 'mainenance' charging, they are intended for applications like street signs where the battery is loaded every night.
The algorithm they use to decide when to switch to float is optimised around that concept from what I can undertand.
Click to expand...

I suspect that's right, and certainly borne out by experience with our Trojans (4xT105S) during a long lay-up, when they used a startling amount of water. They since seem to have fully recovered but it was a worrying experience. Three years ago our regime changed from full-time liveaboard to being on board only a few months each summer. We now disconnect the 340W array and jury-rig a 30W panel during extended absences.

I have to question whether the OP's choice of deep-discharge batteries really suits his usage (or ours). Lead-calcium batteries have such a low self-discharge rate they can confidently be left for six months plus; lead-antimony batteries, like his Trojans, very much not.
 
You must log in or register to reply here.

Share this page

Top