Trojan T105 6v Battery bank advice required !

[nicknorman]

57 minutes ago, meerlaan said:

Yeah I have the manual I remember seeing the terminal I think when the front cover was off.

 

@nicknorman Perhaps easier to see from these photos I am not sure what to look for.

 

The fat black wire from the shunt presumably goes to the rear left battery connection. The other rear connections on the battery bank are the negatives which are all connected together. But there is one rogue small black wire connected to the rear left terminal too. Do you know  where that goes? Perhaps it is a small unimportant thing, but if that wire goes to something that takes significant current then it will cause the meter to read too high an SoC.

Edited November 20, 2017 by nicknorman

[mross]

You HAD a reasonable amount of solar.  Now, in winter, you need to be more involved!  

[nicknorman]

3 minutes ago, meerlaan said:

haha, I think you understand the situation correctly @Sea Dog

I think I am beginning to understand that my trusting my battery monitor has been a massive mistake and hopefully my batteries are still in reasonable condition. after three hours of so charging the charging current is now 20amps

I am surprised once a week is not enough as I have a reasonable amount of solar, but am learning lots this week  

Solar is very seasonal. Your strategy is probably fine in summer, but not in winter. You get about 1/10th of the power from solar in winter, and this corresponds with much longer hours of darkness ie much more use of lighting etc.

[mross]

1 minute ago, nicknorman said:

Do you know  where that goes?

to the battery monitor? OP might find some numbers or marking on the wire itself.

[nicknorman]

Just now, mross said:

to the battery monitor? OP might find some numbers or marking on the wire itself.

I would have thought the battery monitor -ve came from the shunt, but perhaps not.

[nicknorman]

1 hour ago, meerlaan said:

@nicknorman great thanks for that I will change that when I reset my BMV after a proper eq charge, any idea why its reading 100% now ?? as even 4% should be 27amps (I think)

No I don’t fully understand this, but then I don’t have a BMV. My Mastervolt equivalent tend to sit at 99% until the tail current has fallen to the set value, but perhaps the BMV is different and just goes to 100% when the same number of AH that have been taken out, is put back in. Perhaps it has just become way out of sync and or that wire I mentioned is “stealing” current.

Anyway, the important point is to keep charging until the tail current is down to perhaps 1% ie 6A. Also, Trojan batteries like a high charge voltage towards the end and that voltage has to be higher when they are cold. If your batteries are in an unheated area then they will like to finish at 15 to 15.5v. You can set the Victron up to do this if you have the right equipment (interface between Victron and PC).

Once you get your hydrometer we will know whether the batteries have sulphated. I suspect they probably have. But should be recoverable with an equalise charge at 16v or so.

[mross]

I got this photo off t'internet; looks as though you only need to remove four screws to get the cover off.

Try not to lose the screws down the bilge!  They should remain in the cover if you don't unscrew them all the way, just enough to pull the cover off.

It looks safe to do unless you are absolutely determined to shock yourself 

You'll be measuring at the top of those chunky red and black cables.  While cover is off, check those two nuts are tight but don't go berserk.  

The best way to check is to loosen them half a turn and retighten (in case they are loose but stiff)

It might be a good idea to fit a thermometer on the casing, outside, near the top.  A cheapo, magnetic radiator thermometer would do.

Or a cheapo remote fridge or outdoor temp thingy if it goes up to, say 60deg C.  And if it gets that hot you need to do something!

Edited November 20, 2017 by mross

[Sea Dog]

6 minutes ago, meerlaan said:

haha, I think you understand the situation correctly @Sea Dog

I think I am beginning to understand that my trusting my battery monitor has been a massive mistake and hopefully my batteries are still in reasonable condition. after three hours of so charging the charging current is now 20amps

I am surprised once a week is not enough as I have a reasonable amount of solar, but am learning lots this week  

Ok, then here are some quick considerations. Your solar will be doing less and less as winter draws in.  What's important it that you get the batteries fully recharged after each discharge,  by whatever method, preferably daily.  Do this by charging until your tail current is steady - mine gets to less than 2 amps when this is the case. Reset your meter to 100% manually at that point, but also note nicknorman's advice to adjust the auto reset to 1%. It's easiest to see what your tail current gets down to on longer cruising days when you're charging anyway whether the batteries are full or not, so you have no rush to switch off.  Then apply this figure when using your genny.

A battery meter is a great asset but, as you've found out, the percentage state of charge can wander and be misleading. I like to leave it on the Amps scale when charging so I can watch the charge current fall as the batteries fill, and Volts when discharging - Google a battery voltage chart to see what info a 'resting' voltage gives you. Amp hours used on the monitor is handy to see how much you've taken out of your batteries. Conventional wisdom says not to go below a certain percentage. I like to use down to about 60% SoC remaining as my bottom figure, so I avoid using much more than about 150 amp hours from my bank of sealed batteries. Your Trojan's are far more tolerant and someone who runs them might give you a more appropriate figure, but the principle remains that deeper discharges equate to fewer cycles. Even though you might be able to eek out a week before you've used that amount, recharging weekly is not preferred. Who knows though, in summer your solar may get you a full charge daily, so you may gave caught an emerging issue early.  Hope that helps. I note that new replies have already rolled in as I type so maybe you already have the advice you need. Good luck.

[cuthound]

It can be tricky putting the Victron Combi into "equalising charge" mode. It involves switching the unit from on to "charger only" and back to on again and back to "charger only"in a short period of time (0.5 to 2 seconds for each change of switch position).

It is described in the manual, but I struggled with it until I found the YouTube video.

 

 

Edited November 20, 2017 by cuthound
Clarification

[nicknorman]

Can it be put into EQ mode via a laptop / interface cable?

But anyway, my experience with Mastervolt suggests that it’s far better simply to crank up the Absorb / float voltages rather than mess about with a special EQ mode.

Edited November 20, 2017 by nicknorman

[cuthound]

59 minutes ago, nicknorman said:

Can it be put into EQ mode via a laptop / interface cable?

But anyway, my experience with Mastervolt suggests that it’s far better simply to crank up the Absorb / float voltages rather than mess about with a special EQ mode.

I'm not sure, I dont have the Victron software, but thought that it was used to quickly and easily adjust parameters, rather than being used to switch on a specific charging mode.

The equalising mode automatically resets back to a normal charging mode after one hour, so a proper equalising charge to break down extant sulphation requires you to rinse and repeat several times.

However a one hour equalising charge undertaken every 3 months or so (after all sulphation has been  removed by one or more longer equalisation charges) keeps the batteries in good condition. 

[Phil.]

4 hours ago, meerlaan said:

Hi @mross  Could you clarify how I can "measure the volts between the battery and the inverter." I will be checking the battery bolt and crimp in a moment.

I have added some photos of my setup annoyingly after a year I have finally boxed in my inverter so its a little tricker to get to the cables at the bottom :/ 

@nicknorman that would make a lot of sense!! it has only started happening the past 5 or 6 weeks since the temps have been getting colder, I guess the heating element requires more power as the water is colder, thanks so much for your idea I will try your hot water trick.

Hi @Phil.  does it do it automatically?? think I need to check my setup as in the summer months I certainly had enough solar. 

Yes it can be programmed to perform this function automatically if you wish, I believe you can set it to occur between 1 - 250 days. It is easy to just start it manually as well. You should also be able to see how many amp hrs have been produced over the past 180 days so this will guide you as to how little solar you are getting at this time of year compared with the summer months.

[nicknorman]

1 hour ago, cuthound said:

I'm not sure, I dont have the Victron software, but thought that it was used to quickly and easily adjust parameters, rather than being used to switch on a specific charging mode.

The equalising mode automatically resets back to a normal charging mode after one hour, so a proper equalising charge to break down extant sulphation requires you to rinse and repeat several times.

However a one hour equalising charge undertaken every 3 months or so (after all sulphation has been  removed by one or more longer equalisation charges) keeps the batteries in good condition. 

This is why I think it better just to put the Absorb/float voltages right up to do the equalise. Then it runs until you decide it’s enough.

[Dr Bob]

5 hours ago, nicknorman said:

No I don’t fully understand this, but then I don’t have a BMV. My Mastervolt equivalent tend to sit at 99% until the tail current has fallen to the set value, but perhaps the BMV is different and just goes to 100% when the same number of AH that have been taken out, is put back in. Perhaps it has just become way out of sync and or that wire I mentioned is “stealing” current.

 

My BMV counts in the amphrs during charge in line with the 'instantaneous' Amps until it hits the setting that you have defined as the target tail current and then it goes to 100%. Sometimes however it gets totally confused and jumps to 100% when you dont expect it - and the amps in will not be right anyway (charging efficiency), so it is useless to pay any attention to the state of charge value when getting near full. As everyone esle has said, use the tail current.

I reset my 100% every time I get it back to 100%.

You obviously are getting welll charged in the summer/autumn but a once a week charge is just not good enough with no solar in the winter. I cant quite see how you can only be going down to 80%SOC and charging once per week? It hasnt been that sunny has it? Have you got something drawing power without going through the shunt that is taking you lower than 80%. Of course, If the SOC reading is confused and you are not reaching 100%, then reading it when it says 80% could be false. I use the voltage at rest first thing in the morning to give me my approx state of charge - but cross checked against Ahrs out from the last time it was full. Oh to have 1000W of solar!

[MtB]

On 20/11/2017 at 12:06, nicknorman said:

You get about 1/10th of the power from solar in winter

 

This might be the case if you tip your panels up to about 70 degrees to face the (low) winter sun, but in my personal experience if you leave them flat on the roof this figure is closer to 1%.

[meerlaan]

Thanks for all your reponses!!

My hydrometer has arrived and I am planning to check my batteries later today, I am currently giving them a good charge with my genny and keeping an eye on my amps, hoping to get them to rest for 30mins of so before checking my batteries with my hydrometer, is it safe to do direclty after charging for a few hours or should I wait a bit?? do I squirt the acid from the hydrometer back into the battery? do I need to clean before each cell of each batter ?? Thanks for any tips

On another note after charging my batteries for 3 or so hours on tuesday I then left them for about 6 hours or so with everything off and when I came back first thing I did was check the voltage on my BMV it read 13.00v which dosnt make sense as I didnt manage to get tail current down to below 20amps before I went out and 13.00v is above 100% what am I missing.

Thanks

[nicknorman]

Yes definitely put the acid from the hydrometer back into the cell. No need to clean out between cells or batteries. But acid is very pervasive so clean out well after use, and store somewhere where any residual acid won’t cause mayhem.

Yes absolutely fine to check the sg right after charging. Or even during charging!

To get an accurate reading you need to adjust the actual reading for temperature, so you need to have an idea of the battery electrolyte temperature (within say 5 degrees). If the electrolyte is cooler than nominal (25C I think) you have to subtract from the measured value to get the real value.

 

As to the 13v, this is just residual “surface charge” effect. It takes longer to disperse with cold batteries and 6 hrs isn’t enough. If you put a reasonable load on, the voltage will fall fairly quickly to a value representative of the SoC.

Edited November 24, 2017 by nicknorman

[WotEver]

1 minute ago, nicknorman said:

To get an accurate reading you need to adjust the actual reading for temperature

I seem to recall that OP has bought a temperature compensated hydrometer. Or maybe that was another thread?

[nicknorman]

5 minutes ago, WotEver said:

I seem to recall that OP has bought a temperature compensated hydrometer. Or maybe that was another thread?

Oh yes, you’re right.

[meerlaan]

Great thanks @nicknorman just thought best to check, thanks thanks for explaining the 13v

Will post results up later.

[meerlaan]

So it took me a little longer to have enough time on the boat to charge the batteries for long enough to do a SG test.

Today I charged my batteries for about 9 hours using my genny, my victron mulitplus didnt go into float until about 8.5 hours, ( I happened to be watching my BMV when it did) the amps where reading 4.8a (ish it was still jumping around a little) and 14.59v, it switched to float mode and this dropped to 2.07a and fluctuated to 2.33a the voltage dropped to 13.92v and crept up to 14.24v and then rested at 13.96v with the current at 3.06a.

I reset my BMV and set the tail current to 1%, I noticed my charge voltage is 13.2v is this correct ??

Just before batteries were in float mode, amps where probably down to 5.89a I did a SG test for all my batteries. I took three readings of each just to be sure, results are:

(All in chronological order of when I took readings)

Battery 1

[Front]  1.185 (first reading) , 1.255 , 1.255 

[Middle] 1.245 , 1.250 , 1.250

[Rear] 1.255 , 1.255 , 1.270

Battery 2

[Front]  1.245 , 1.270 , 1.270 

[Middle] 1.240 , 1.260 , 1.255

[Rear] 1.275 , 1.275 , 1.260

Battery 3

[Front]  1.260 , 1.255 , 1.255 

[Middle] 1.245 , 1.250 , 1.245

[Rear] 1.260 , 1.250 , 1.255

Battery 4

[Front]  1.255 , 1.255 , 1.255 

[Middle] 1.255 , 1.265 , 1.260

[Rear] 1.245 , 1.255 , 1.245

Battery 5

[Front]  1.250 , 1.250 , 1.250 

[Middle] 1.250 , 1.260 , 1.260

[Rear] 1.245 , 1.245 , 1.250

Battery 6

[Front]  1.260 , 1.260 , 1.260 

[Middle] 1.250 , 1.255 , 1.255

[Rear] 1.255 , 1.265 , 1.260

Anyone make any sense of these ?? Hoping to do an eq charge at the weekend and retest, any idea how long I should do this for ??

Thanks for all your help, Hopefully these results dont show my batteries to be ruined :/

 

 

[cuthound]

Definitely in need of more charging and then equalising.

A fully charged battery should have an SG of around 1265-1275 @ 25°C. 

Also the first cell of battery 1 (SG 1185) is either faulty or a mis-reading.

Take the SG of that cell again and if it is still that low then you will need to replace that battery.

[Tony Brooks]

I think they show the batteries are well charged but not fully charged. I would do the EQ, let the batteries cool and retest. personally if you had time I would have turned the charger off and back on again when it went into float.

As for how long to do the equalising charge I would not like to say because to do the job properly you should be monitoring the battery temperature, current & electrolyte level throughout the process. Without this I would try a couple of hours.

2 minutes ago, cuthound said:

Definitely in need of more charging and then equalising.

A fully charged battery should have an SG of around 1265-1275 @ 25°C. 

Also the first cell of battery 1 (SG 1185) is either faulty or a mis-reading.

Take the SG of that cell again and if it is still that low then you will need to replace that battery.

I agree with that as it came up in the subsequent readings I put it down to a misread. Retest it when you get back to the boat and before charging. If it has dropped then its probably new battery time. However repeat the process of charge, rest for some days & retest to be sure.

[nicknorman]

9 hours ago, meerlaan said:

So it took me a little longer to have enough time on the boat to charge the batteries for long enough to do a SG test.

Today I charged my batteries for about 9 hours using my genny, my victron mulitplus didnt go into float until about 8.5 hours, ( I happened to be watching my BMV when it did) the amps where reading 4.8a (ish it was still jumping around a little) and 14.59v, it switched to float mode and this dropped to 2.07a and fluctuated to 2.33a the voltage dropped to 13.92v and crept up to 14.24v and then rested at 13.96v with the current at 3.06a.

I reset my BMV and set the tail current to 1%, I noticed my charge voltage is 13.2v is this correct ??

Just before batteries were in float mode, amps where probably down to 5.89a I did a SG test for all my batteries. I took three readings of each just to be sure, results are:

(All in chronological order of when I took readings)

Battery 1

[Front]  1.185 (first reading) , 1.255 , 1.255 

[Middle] 1.245 , 1.250 , 1.250

[Rear] 1.255 , 1.255 , 1.270

Battery 2

[Front]  1.245 , 1.270 , 1.270 

[Middle] 1.240 , 1.260 , 1.255

[Rear] 1.275 , 1.275 , 1.260

Battery 3

[Front]  1.260 , 1.255 , 1.255 

[Middle] 1.245 , 1.250 , 1.245

[Rear] 1.260 , 1.250 , 1.255

Battery 4

[Front]  1.255 , 1.255 , 1.255 

[Middle] 1.255 , 1.265 , 1.260

[Rear] 1.245 , 1.255 , 1.245

Battery 5

[Front]  1.250 , 1.250 , 1.250 

[Middle] 1.250 , 1.260 , 1.260

[Rear] 1.245 , 1.245 , 1.250

Battery 6

[Front]  1.260 , 1.260 , 1.260 

[Middle] 1.250 , 1.255 , 1.255

[Rear] 1.255 , 1.265 , 1.260

Anyone make any sense of these ?? Hoping to do an eq charge at the weekend and retest, any idea how long I should do this for ??

Thanks for all your help, Hopefully these results dont show my batteries to be ruined :/

 

 

There is a lot of scatter in those results, which tells me the measuring device isn’t very good. I would get a refractometer type which is pretty accurate and repeatable.

Anyway the reading should be 1.277 for Trojans, so you have a fair bit of sulphation. Only solution is a long equalise charge at 15.5-16v. Top up the electrolyte first. 

[WotEver]

1 hour ago, nicknorman said:

Only solution is a long equalise charge at 15.5-16v.

How long, Nick? Couple of hours? More?