Trojan T105 6v Battery bank advice required !

[rusty69]

Is the engine starting battery fixed?

Edited November 20, 2017 by rusty69

[meerlaan]

not really :/

[rusty69]

It will be interesting to see what the current and voltage is at 100%

Edited November 20, 2017 by rusty69

[meerlaan]

Well its reading a 100% now and its still in absorption, current was reading about 60amps but falling... now 58 ish

 

[system 4-50]

Your Multiplus is going to overheat! The picture appears to show the top RHS adjacent to the cupboard wall!

[mross]

There should be a red and a black cable running from the batteries to the Victron.  To verify that they are correctly sized and tightened you should try and measure the voltage from one end of the red cable to the other end of the red cable with as much load on the Victron as possible.  But don't do this if you are not confident.  You might just create a big spark if you poke yer leads where you shouldn't oughta!

Can you get a friendly neighbour to help?

The black cable, that runs from the top left battery post in your photo, to the brass terminal in the bottom left, looks thinner than the other cables?  I wonder if others could comment?

It may be that the insulation is just thinner.

[rusty69]

4 minutes ago, meerlaan said:

Well its reading a 100% now and its still in absorption, current was reading about 60amps but falling... now 58 ish

 

So, do you normally turn off charger when it reaches 100%?

[meerlaan]

@system 4-50 I hope it will be ok, I have done my best to vent it as much as possible, it is a little hard to see but the plywood has holes that continue all the was down to the sides of the multiplus.

@rusty69 Yeah, every weekend I try to give my batteries a 'good charge' and usually can hear when the genny quietens down I would check and if there reading 100% I would stop charging :/

[mross]

It might be easier just to measure the 12v at the batteries and measure the 12v at the input terminals on the Victron when the washing machine is running.  The difference will be the volt drop in the cables and isolator switch.

[meerlaan]

@mross The electrics were done recently by someone who seemed to do a very good job and checked all the cable sizes with me around so I would hope they are right

Measuring at batteries and at input terminals makes sense to me but could you clarify where I should stick my red and black prongs!

Thanks

I wonder why my monitor is reading 100% and 50amps but its still in absorption on my mulitplus,  I am sure it is usually on float when it reaches 100% and I turn it off. This make sense to anyone??

[nicknorman]

Out of the box, the BMV resets to 100% when the tail current reaches 4%. This is far too high IMO and will encourage you to undercharge. I would change that setting to 1%.

4% is 27A so does not fully explain the high current. I wonder if all circuits that supply current go through the shunt? What can happen is that all charging current goes through the shunt, but not all discharging current goes through the shunt. This fools the BMV into thinking the batteries are at a higher SoC than they actually are.

Edited November 20, 2017 by nicknorman

[nicknorman]

It’s difficult to see from the photos but there do seem to be a few random wires connected to the batteries. Follow the thick black wire from the shunt back to battery negative. This should be the only wire connected to the battery negative, apart from the interconnects to the other domestic battery negatives. If there are ANY other wires on the battery negatives, this is wrong.

[meerlaan]

@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)

[mross]

Can you post a photo of the connections at the bottom of the Victron?  I can edit it to show you where to measure.  On the batteries, measure from top left to bottom right.

[MtB]

On 20/11/2017 at 09:33, meerlaan said:

I have finally boxed in my inverter so its a little tricker to get to the cables at the bottom :/ 

 

As  general comment it is never a Good Idea to box in equipment of any nature. Access for maintenance or repair WILL eventually be needed. And I dunno about your Victron in particular but it is highly likely it needs a good airflow/ventilation through it for cooling. Boxing restricts or stops this. 

[mross]

Do you have the manual for the Victron?  https://www.victronenergy.com/upload/documents/Manual - MultiPlus 3k 230V Ve.Bus enabled - rev 00 - EN NL.pdf

Appendix 1 (after page 42) shows the connections but I doubt you can reach them without removing the cover.  I think you should have a knowledgeable friend or professional with you before you take any covers off.

Someone who owns a Victron can advise if the terminals are readily accessible.

[Robbo]

1 hour ago, meerlaan said:

 

 

Not read the whole thread so not sure if already mentioned., but boxing the combi isn't good, the air is sucked in from the bottom exits from the top sides and they are now basically covered and will reduce performance and maybe lifetime of the device.

I'm also guessing the Outback will suffer as well.

Edited November 20, 2017 by Robbo

[meerlaan]

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.

8

Edited November 20, 2017 by meerlaan

[Sea Dog]

1 hour ago, meerlaan said:

@mross

I wonder why my monitor is reading 100% and 50amps but its still in absorption on my mulitplus,  I am sure it is usually on float when it reaches 100% and I turn it off. This make sense to anyone??

I'm late into this, so forgive me if I've missed something.

Are you aware that your charger will go into 'bulk' initially every time you switch it off and then on again? After a short period, it will then go to 'absorption' for a while and eventually to 'float'. This will occur even with fully charged batteries. Also, if you draw anything much of a domestic load, the charger can drop out of float and back into absorption. All the detail on this stuff, including voltages and timings, will be in the appropriate manual. Therefore, what phase of charge your charger has gone into, doesn't necessarily tell you the state of charge of your batteries and may even appear to disagree with your perception.

As someone above mentioned, if you have a clever charger like in the Victron Multiplus, why are you switching it off?  Float mode is there to keep your batteries in a good state and the later Victrons will drop into an even lower state if there's been no draw from the batteries for a while (standby iirc) where they use almost nothing. They will also, on a regular basis, return to a bulk charge at intervals to keep the batteries in good shape. 

Oh, and now the pictures have popped up, to access the the terminals, there's a smaller blue front cover behind your lower white panel which you'll need access to. 4 screws hold that in place and you'll have access to the lower 2 screws on the front panel. The lower panel gives access to the cable entries and the large panel gets you in to the main terminals themselves. The connections are not complicated. Careful where you put you fingers!

Edited November 20, 2017 by Sea Dog
Terminals

[mross]

Seadog- can he expose the 12v input connections without risk?  I'm thinking of the 240v connections and the chunky capacitors in there.  Easy for you and me but not so for a non-techie.

To the OP, if you do take covers off, you would measure between one nut/bolt marked '+ BATTERY' and one nut/bolt marked  '- BATTERY'

While removing any covers, turn off battery isolators, shore supply and generator.

Edited November 20, 2017 by mross

[meerlaan]

@Sea Dog Thanks for your response I think I basically understood / understand the bulk - absorption - float stages but am prepared for my understanding to be wrong! I thought float charge was a lower amp charge given when the batteries had almost reached 100%. So I am confused why currently they have been charging for a few hours with my monitor saying 100% but still in absorption stage my amps currently reading 36ish

It is the generator that I am switching off, I have a portable honda job. I am using this to charge the batteries up once a week. Once I thought sufficient charging had been done I would turn off.

[Sea Dog]

10 minutes ago, mross said:

Seadog- can he expose the 12v input connections without risk?  I'm thinking of the 240v connections and the chunky capacitors in there.  Easy for you and me but not so for a non-techie.

To the OP, if you do take covers off, you would measure between one nut/bolt marked '+ BATTERY' and one nut/bolt marked  '- BATTERY'

While removing any covers, turn off battery isolators, shore supply and generator.

A picture paints a thousand words.  I did say 'careful where you put your fingers', but you put it so much more eloquently!

[meerlaan]

thanks mross that is very helpful 

[Sea Dog]

4 minutes ago, meerlaan said:

@Sea Dog 

It is the generator that I am switching off, I have a portable honda job. I am using this to charge the batteries up once a week. Once I thought sufficient charging had been done I would turn off.

Oh-oh. This takes us into other territory! Once a week isn't enough. From this comment, if I understand you correctly, my take now is that the 100% reading is misleading and the high current you're seeing is the charging current your genny/Charger combination is stuffing into your batteries. This shows they're far from full.

I'm gonna stop there because I came to this thread late purely to offer the advice about the charger states and I might be going off on a tangent from where the others have been guiding you. Anyway, I need to buy some popcorn...!  

[meerlaan]

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