[Spruce]

One question I have is about when to charge , we are told to get them back on charge as soon as possible but I thought they had to sit dormant for about 4 hours so they can settle and give the charger a true reading of state of charge ?

Which is it ? 

Having just got a Numax 105 that will be charged every night I am starting to question my chargers , both smart , one is an Avon 8 Amp and the other a Halfords with 2 settings , standard at 5 Amp and sealed at 3.7 Amp , out of the two I trust the Halfords one more on sealed setting but am wondering if it will put a charge in fast enough ?

I have power analysers on the van so know what comes out daily , I am just about to fit an identical analyser inline on my charger to see if the charger puts in what I know has come out at the time it switches to float and maintain

TBH I don't often check the batteries actual state of charge after 4 hours all that often. Generally I find that there isn't that much difference after a couple of hours.
I just used to plug the charger in when I got home and let it do its job overnight.  I have to say over the years its done a good job. Since I've had this charger and done this charging procedure I haven't had a battery last less than 3 years and that was a cheap Orange battery - both in name and in colour I got from Ropers Caravan World over 12 years ago now.

I didn't put the charger on last night. We did a bit of work yesterday morning before the rain came in and drove 5 miles home. Checking the leisure battery voltage is much easier with the Victron battery monitor as I just step outside the front door, point my phone at the van on the drive and activate the app.

In fact I have just done that and the battery voltage is 12.95v so fully charged. Its my van starter battery that's a problem as that has dropped to 12.56 volts. The van hasn't moved since 2pm yesterday.

If I put the charger onto the battery today (I'm not going to as its still raining) the charger will go straight to float mode.

[P @ F]

My little analyser experiment appears to have worked, yesterday I ran the system until 5Amps was taken from my fully charged battery.
I then let the battery sit for a few hours while I did other bits and wired in the spare analyser to my charger .
It gave the results as follows ...
Standard - 14.4V @ 4 Amp
Sealed      - 14.4V @ 2 Amp

I decided to go with the sealed setting as only 5 Amp was missing
I assumed that if the charge rates stayed the same that it would take about 2.5 hours to get to float and maintain mode .
It actually took 3 hours and the charge rates did stay at the same levels , battery has now been resting overnight, when I get out of bed in a bit I will take a multimeter reading then whack it back on a sealed charge to see what it does !

[P @ F]

I think that when I do a normal 6 hour stint at around 24 Amps use I may use the standard setting as the voltages of both settings were the same , tbh I was expecting the sealed voltage to be 14.2V but then it’s only a £40 Halfords charger isn’t it   

[P @ F]

Ok , so this was the voltage  with an overnight rest

[P @ F]

And this is back on sealed charge at 12.10 , let’s see what it takes in Amps once it’s hit maintain again

[P @ F]

That didn’t take long , 13 minutes, I can only assume that the battery is fully charged then 

[Spruce]

With both of those analyzers monitoring  charging and output current you will get a better idea how your battery charging is going.

The Victron Battery monitor I have doesn't give me that level of detail.  It seems to re-calibrate the system battery back to 100% fully charged when it records a voltage anywhere between 12.7 volts and above.

I can finish the last job and before leaving I see the battery monitor tells me I have consumed 5 amps from the battery. When I get home the battery monitor indicates they I'm still 2amps down.  But once the van has been stationary for a few hours the monitor resets itself to 100% fully charged and clears the 2 amps deficit using the battery reading voltage at rest.
This is exactly what happened yesterday and the battery voltage shows 12.95 volts after resting all night.

Where the cutoff point is when your charger goes from bulk to absorption and float charge is determined by the manufacturer of the battery charger.  I don't know exactly how the manufacturers determine this point but when bulk charging is finished but I'm assuming the its to do with a combination of charge rate and time.
 
 

[P @ F]

It’s all very confusing eh !
As long as my analyser on the bench charger puts in what the analyser on the van says has been used I don’t think I can go far wrong !
There is of course then the solar in to be accounted for too !

So my formula will be...van analyser amps out minus solar amps in equals amount of charger amps registered before float is reached.   

[dazmond]

under load(my heater shutting down and reeling hose in at the same time)at the end of my working day my voltage can read as low as 12.2.......but then goes up to 12.6 after the heaters 3 min shut off finishes and hose has been reeled in......is this normal?

[Spruce]

under load(my heater shutting down and reeling hose in at the same time)at the end of my working day my voltage can read as low as 12.2.......but then goes up to 12.6 after the heaters 3 min shut off finishes and hose has been reeled in......is this normal?

Yes. The voltage drops when the battery is under load but 'recovers' when the load is removed.

This is why Spring and Varistream controllers are programmed to shut power off when the battery voltage drops to 10.3/10.4v under load. If you left that battery for a few hours when the controllers shut down the battery would return to around 12v.
10.4v under load is flat as is a rested battery showing 12.0v.

[dazmond]

Thanks spruce......

Also when I start my engine in the morning my voltage is reading 14v and falls to 13.7 when I fire the heater up....
Is this normal too?

[Jonny 87]

I’m still in a quandary what batteries to buy. 

The more I research the more I seem To confuse myself.

I’ve been looking into AGM batteries as they seem
To have far better “deep cycle” facilities.

Who knows. I might just end up buying 2 yuasa 115 leisure batteries and see how long they last.

Aslong as I get 2 years Atleast out of them then I suppose I shouldn’t complain.

My power use has just really increased the last few years, whereas my batteries haven’t. My last yuasa battery lasted 5 years, but that was with a cold system and manually reels. Big difference to now.

[Spruce]

Thanks spruce......

Also when I start my engine in the morning my voltage is reading 14v and falls to 13.7 when I fire the heater up....
Is this normal too?

The voltage you are reading is the driving force of the power you want to start your heater.  As soon as you demand the battery to do a task the voltage will drop.

14.0v is not a stabalized voltage. If you left the battery for 4 hours it would drop to 12.7v or above. So the moment your take power from that battery showing a high voltage, you are helping to stabalise the voltage across the battery cells. In your case the battery voltage will not recover from 13.7v if you switched all power draw from the battery.

[dazmond]

I’m still in a quandary what batteries to buy. 

The more I research the more I seem To confuse myself.

I’ve been looking into AGM batteries as they seem
To have far better “deep cycle” facilities.

Who knows. I might just end up buying 2 yuasa 115 leisure batteries and see how long they last.

Aslong as I get 2 years Atleast out of them then I suppose I shouldn’t complain.

My power use has just really increased the last few years, whereas my batteries haven’t. My last yuasa battery lasted 5 years, but that was with a cold system and manually reels. Big difference to now.

why dont you phone grippatank  and ask their advice on what batteries they recommend?im sure oliver would be helpful.....

[P @ F]

2 of these

[P @ F]

Or better still 2 of these !

[Jonny 87]

Thanks P@f

Numax seem to be what grippa recommend too.
Great minds think alike. 

[dazmond]

Your best bet is to get a numax commercial 20amp charger too and charge up every night.....

[Jonny 87]

Your best bet is to get a numax commercial 20amp charger too and charge up every night.....

Already do daz. A ctek 25amp charger that cost me  a pretty penny. I think I’ve just had a failed battery.

[Jonny 87]

You know you’ve ordered 2 heavy duty batteries when they come on a pallet. 

Numax leisure batteries, 180amp each.

It’s probably overkill, but call it an experiment. My theory is that if I’ve got excess power, then I should be depleting the batteries very little, and I’m
Also going to charge them every night. (My ctek MXS 25 charger is built for 300 amp plus).

If I get less than 2 years out of these batteries then I’ll go back to two standard 115 amp batteries.