Battery question,

Mr B2 · Senior Member

Battery question,

brian · Guru

Mr B2 wrote:

My house battery is an 8D,
When I put it on the 240 volt charger it charges to the full four bars on my dash,
I use the trickle side of the charger when it gets up near full, and then leave it on till the four bars are full,
When camping it has gone down to one bar, No Solar and no Generator,
Driving home, the Engine alternator brings it back up to four bars, 3 or 400 miles, 120 amps on the main engine alternator,
House and vehicle batterys are separate systems, But its all automatic on charging both batterys from the engine,
Now I have the solar connected up, Its connected to charge only the house battery,
The bars only come up to 3/4 on the dash monitor,
The engine battery monitor is a different guage, It stays fully charged, Its not used except for starting the engine, Its an 8D also,
Its been sitting in full sun for over two weeks, with no shade on the panels,
what does the reset button on the MPPT controller actually do,
Will it reset the controller to charge the battery more, or alter the charge in any way,
Is there some way I can make the dash monitor register the four bars instead of just three,
Or is it some thing I just have to live with,

A few things to be aware of:-

1. The bar graph is nothing more than a very basic voltage monitor, it does not tell you with any certainty what the true state of charge of the battery is. The meter will simply reflect the output voltage of the charger, not the true rested voltage of the battery.

2. The terminal voltage of a battery under charge will very quickly rise to the same voltage of the source, this makes a simple volt meter redundant for accurate state of charge readings other than when the battery has been at rest for at least 8 hours, ie no load or charge applied.

3. The only way to have a reasonable idea of battery state of charge is by Coulomb counting, ie Ah in versus Ah out as counted from when the battery was known to be fully charged.

4. The amps rating of your alternator has almost no bearing on the rate of charge that you will get into your battery. The charge rate is primarily controlled by the battery's charge acceptance rate which will very rarely be anywhere near the capacity of the alternator.

5. You don't say what wattage your solar array is, or the type of MPPT controller, so it's not possible to offer any thoughts on those questions.

Mr B2 · Senior Member

Thanks Brian,

The solar panels are 270 Watts, They are all working, I have tested them,

The Controller is a Wellsea 30 amp MPPT, Its Chinese,

It replaced my 10 Amp Morningstar one that got drowned,

All power has been turned off in the Coach, So it isnt drawing any power out of the batterys,

What I dont understand is,

the engine and Battery charger will bring the dash monitor up to the full four bars,

The solar only brings it up to 3 bars, and I think after a fornight or so, with full sun on the panels, It should soak the batterys to full charge,

Is the Controller set too low,

Please keep it simple, Electricity is not my Forte,

All this Solar Equiptment was Purchased to replace the drowned electrics on my boat,

I just installed it on the Coach, I will purchase new ones again for the boat,

-- Edited by Mr B2 on Monday 17th of February 2014 12:42:52 PM

-- Edited by Mr B2 on Monday 17th of February 2014 12:46:11 PM

brian · Guru

From memory the Wellsee 12v charger has a maximum charge voltage of 13.7v which is a bit lower than most and may not be high enough to set the upper bar on your meter.

This doesn't necessarily mean that the battery is not fully charging but it will take longer than it would if you were getting a higher input voltage.

If you get the 4 bars on the dash monitor, does it stay at 4 bars after you stop charging, and if so, for how long, and at what voltage does it extinguish?

Have you checked the rested voltage of the battery when you are only getting 3 bars on the meter?

Do you have specs for the meter?

I have no idea what the reset button does, it may be to reset the Ah info, or the overvoltage or undervoltage cutouts, or something entirely different.

Mr B2 · Senior Member

If the four bars are up on the dash, They stay lit till I go camping, Then take about 3 days to get down to the second bar, with out really conserving power,

I wanted to know how much battery I was using, With two people on board,

I get 3 nights and then I need to charge the batterys without any solar, Solo,

Thats with out any charging going in,

But with the solar panels on and connected, Two days camping, It stayed on the 3/4 mark,

I would much rather it stayed just below fully charged rather then fully charged,

If I get a spike or whatever, The battery will still take that bit extra charge with out cooking itself,

I dont know if that is reality or not,

It could also be the Chargers position saying its full, on the 3/4 mark,

Up untill recently till I retired, I had sparkys running out my ears, Onsite, I wanted some thing done, Whistle up one of the good sparkys, Can you fix that for me Please,

Yep no problem, So I never bothered even trying to learn to read a meter, I still cant, Never had a need too, Two wires with a globe in the middle is all I ever needed for my self,

Big jobs, I just paid and had it done, By which sparky, was my choice,

Its now 3 weeks its been sitting there, Its still on the 3 Bars, I dont think it will increase to four bars,

It took 3 days to get the battery up to full with the charger, But that dont have a cutout on it, So I disconnected it before it was fully full, as soon as the four bars came up, shut it off, My charger will cook the battery,

As long as it charges more than I use, I am happy with it, Or bigger panels if it dont,

SnowT · Guru

My B do you self a favor make sure that you clean up every exposed surface that is used for a connection..
- Any form of corrosion will act as a source of resistance..

Better to reduce the resistance to 0 than have it affect the current flow..

Juergen

Wirroff · Senior Member

This is the only user manual I can find for the Wellsee MPPT30 - It may help in some way although it's in Chinglish!

Mr B2 · Senior Member

SnowT wrote:
My B do you self a favor make sure that you clean up every exposed surface that is used for a connection..
- Any form of corrosion will act as a source of resistance..

Better to reduce the resistance to 0 than have it affect the current flow..

Juergen

They are all spotless my connections, I use a bit of grease to allow the two surfaces to squeeze together giving full contact, Then cover them over with grease, Air tite,

This way I get years of trouble free use out of them, Thats the battery terminals Etc, all other electrical joins are soldered and taped,

brian · Guru

Mr B2 wrote:
SnowT wrote:
My B do you self a favor make sure that you clean up every exposed surface that is used for a connection..
- Any form of corrosion will act as a source of resistance..

Better to reduce the resistance to 0 than have it affect the current flow..

Juergen
They are all spotless my connections, I use a bit of grease to allow the two surfaces to squeeze together giving full contact, Then cover them over with grease, Air tite,
This way I get years of trouble free use out of them, Thats the battery terminals Etc, all other electrical joins are soldered and taped,

I hope the grease that you're using is highly electrically conductive, many are very good insulators and so will cause issues if you put it between the joints.

PeterD · Guru

Mr B2 wrote:
They are all spotless my connections, I use a bit of grease to allow the two surfaces to squeeze together giving full contact, Then cover them over with grease, Air tite,

Grease = grime, or in other words not the best in the way of cleanliness. Clean your connections before assembly. Connect up and tighten all joints. Then apply any protective coatings.

Mr B2 · Senior Member

The grease is not conductive, I know that, The pressure thats applied squeezes all the grease out and gives a perfect connection,

The grease allows the two surfaces to slide together making one surface with out gaps,

Its worked for me with no problems for over forty five years, The only time I touch battery terminals or cables is when the Batterys are dead from old age,

Do it once, Do it right, Forget it,

Thats one of my connections laying on the ground,

I forgot to add, when I pull my connections apart after years of service, They are still shiny and clean,

My time is very valuable, I dont get paid if my equiptment breaks down, So I make sure it is totally reliable to start with,

My complete system for the Coach that I actually had to pay for, Was $40-00 for the Controller,

Every thing else came out of my workshop, I already had it sitting there, Or hanging on the walls,

Fixed the spelling mistake, I missed that one, Hahahaha. I do my own spell check,

-- Edited by Mr B2 on Monday 17th of February 2014 08:47:19 PM

-- Edited by Mr B2 on Monday 17th of February 2014 08:49:05 PM

-- Edited by Mr B2 on Monday 17th of February 2014 10:35:33 PM

brian · Guru

Mr B2 wrote:

Its worked for me with problems for over forty five years, The only time I touch battery terminals or cables is when the Batterys are dead from old age,

A Freudian slip perchance?

-- Edited by Mr B2 on Monday 17th of February 2014 08:47:19 PM

-- Edited by Mr B2 on Monday 17th of February 2014 08:49:05 PM