Question about battery level reading

[spud159]

I have a question regarding the battery level indicator in our Murvi.
Both leisure batteries are reading around 14v. They are being constantly topped up by a 150 watt solar panel, and the solar controller is saving they are full. The van has been parked on the drive for 5 days.
When I check the Kigass info control panel the battery level indicator is showing around 40%… I don’t know what that means ? Why wouldn’t that be showing as full?
Any help/ guidance would be appreciated
Thanks
Steve

 

[Vanman]

You can only really tell the amount of power in a battery by disconnecting it for an hour and then trying it with a multi-meter. If it's showing 14v then it is charging (from solar or other) as a full battery should show about 12.8v depending on type.

 

[spud159]

Thank you
Does that mean I should ignore the battery level indicator then?

 

[Phill D]

a lead acid battery at 40% would show around 11.9Volts only and be in danger of dying.

can our level indicator be calibrated or reset ?

 

[spud159]

I’m sure that batteries are fully charged and I’ve reset it, and it’s back to being 100% again.
Still entirely sure what’s it’s telling me though?
Thanks for help

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[Lenny HB]

14v is the charging voltage from the solar. If your solar regular is a 2 or 3 stage charger (most are at least 2 stage) as the van has not been used for 5 days I would expect the batteries to be fully charged and the regulator dropped to a 13.8v float charge.

It suggests the batteries may have had it.
I would disconnect or cover the solar panels leave it for an hour then measure the battery voltage.

 

[Vanman]

I’m sure that batteries are fully charged and I’ve reset it, and it’s back to being 100% again.
Still entirely sure what’s it’s telling me though?
Thanks for help

If you disconnect any external power input (EHU) and turn the engine off, then an hour after dark it might tell you somewhere near the truth, Try not to draw any power in the meantime - use a torch and turn the fridge / heating / alarms off.

 

[autorouter]

There is a possibility that the gauge is correct. The voltage is not a good guide to how full the batteries are. If the batteries were charging from a low level, then at 40% they may well be indicating 14V.

What type of solar controller is it? PWM or MPPT? I'm not familiar with the Kigass battery gauge, so I don't know if it is a simple voltage monitor or the more complex 'Amp-hour' (Ah) meter, with a shunt. If it's an Ah meter, it may need resetting.

Usually that is done when you are quite certain the battery is 100% full. For example if it's been on hookup for 24 hours and no loads switched on. Unfortunately I don't know the procedure for resetting the gauge, maybe someone with a manual for it can help.

 

[autorouter]

I’m sure that batteries are fully charged and I’ve reset it, and it’s back to being 100% again.
Still entirely sure what’s it’s telling me though?

An amp-hour (Ah) gauge is a much better indicator of the state of charge than a simple voltage monitor, especially if you have solar power. Basically it measures the amps into and out of the battery, minute by minute. There's a small chip that keeps a continuous count of how much amps goes into and out of the battery.

So if you are using power while the solar is charging it, the solar controller might keep the voltage up at 14V, but the charge in the battery might be going down if you are taking out more than the solar can put in. The gauge will be an accurate indication of the state of charge, but the voltage doesn't really tell you much, except that the battery is being charged.