Battery Charge/Voltages

[VXman]

I may be being paranoid due to ease of checking the voltages on the panel but....

I have a brand new Burstner (whatever 'new' means - not sure how long it had been on the forecourt). Had it for 3 weeks but obviously not really used it other than drive it 80 miles from the dealers and one local trip for a few miles. I have plugged in the EHU for a few hours several times.

The engine battery and the leisure battery seem to sit at around 12.2 Volts most of the time (which I take to be, looking around google, 60% capacity) higher after a charge but soon settles down to this after a few days. Nothing is switched on other than the alarm.

Is this OK/normal or should it be higher?

 

[pappajohn]

If that's a consistent reading its whatever your reading the voltage with that's faulty/inaccurate.

 

[VXman]

If that's a consistent reading its whatever your reading the voltage with that's faulty/inaccurate.

As said above - that's what the meter reads on the standard Burtstner Electricity Control panel. I will access the batteries and check with my multi meter and see if it matches up.

 

[Badknee]

My two leisure batteries and starter battery when driving read 14.3v. At rest read 12.7v, on float while on ehu 13.4v, when on anti sulphate mode 14.3v
this info from three voltage read outs, I know, ocd

 

[pappajohn]

Apologies, I skipped the top two lines.

As both batteries appear part discharged I would say it is the panel readout which is wrong.
Two new batteries reading identical low voltage is very unlikely

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[donkey]

You have had the vehicle on EHU 'for a few hours'.
Before carrying out any meaningful testing the EHU needs to connected for a day or two. That will ensure the batteries have received a full charge.
Geoff

 

[VXman]

You have had the vehicle on EHU 'for a few hours'.
Before carrying out any meaningful testing the EHU needs to connected for a day or two. That will ensure the batteries have received a full charge.
Geoff

Really? How are they charging then - just a trickle? I was comparing to a car battery charger. You would expect a full charge in 5 or 6 hours I would have thought?

 

[Terry]

Apologies, I skipped the top two lines.

As both batteries appear part discharged I would say it is the panel readout which is wrong.
Two new batteries reading identical low voltage is very unlikely

Surely the batteries will be connected together so one may be goosed pulling the other down / both goosed or as you say faulty reading. Only way to be sure is with multimeter Give them a full charge and see reading from mm next day then Seperate batts and read after a couple of hours and check again ....

 

[VXman]

Surely the batteries will be connected together so one may be goosed pulling the other down / both goosed or as you say faulty reading. Only way to be sure is with multimeter Give them a full charge and see reading from mm next day then Seperate batts and read after a couple of hours and check again ....

As far as I am aware there is no connection between the two batteries. They both charge from the alternator or EHU but are separate when discharging to ensure that you don't flatten the engine battery when using the habitation electricity when parked up.

 

[Terry]

My misunderstanding only way to check then is with MM Sounds like your van reading is faulty, I doubt both would be giving same reading

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[Tombola]

Really? How are they charging then - just a trickle? I was comparing to a car battery charger. You would expect a full charge in 5 or 6 hours I would have thought?

Depends on how many Amps your on board charger is thrwoing out/rated at.
Some are as little as 10apms and then take off the odd amp if other things are using as a powre source.

 

[donkey]

You would need to look at the specs for the charger. Also, what battery technologies are we talking about?

There are huge differences between chargers, and even more between batteries.

A basic charger connected to basic batteries that have been allowed to run quite low, would try to wack a load of charge in, which could raise the surface voltage. This in turn could indicate to the charger that the batteries were charged and so basically switch off.

If you have AGM, then they need several hours of absorption charge, or they will never be fully charged and will die an early death.

If you have wet lead acid then there is no better way of checking the state of charge than a hydrometer to measure the specific gravity of the electrolyte.

Geoff

 

[VXman]

You would need to look at the specs for the charger. Also, what battery technologies are we talking about?

There are huge differences between chargers, and even more between batteries.

A basic charger connected to basic batteries that have been allowed to run quite low, would try to wack a load of charge in, which could raise the surface voltage. This in turn could indicate to the charger that the batteries were charged and so basically switch off.

If you have AGM, then they need several hours of absorption charge, or they will never be fully charged and will die an early death.

If you have wet lead acid then there is no better way of checking the state of charge than a hydrometer to measure the specific gravity of the electrolyte.

Geoff

AGM batteries 90AH I think.

I think charger part of the Elektroblock EBL 119 Power Supply unit. ah yes-

The motor home manual says 'when attached to the EHU the engine battery and the leisure battery are automatically charged by the charging unit on the transformer/rectifier. The starter battery is only charged with a float charge. The charging current is adapted to suit the condition of battery. The ensures it is not possible to overload the battery.'

 

[pappajohn]

Regardless of battery charger type or make its extremely unlikely both batteries would read exactly 12.2v.
The digital panel readout is wrong and a multimeter check on each battery will prove or disprove.

 

[Tombola]

Looks llike the charger ia 18A so is plenty to charge a 90ah battery.

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[VXman]

Regardless of battery charger type or make its extremely unlikely both batteries would read exactly 12.2v.
The digital panel readout is wrong and a multimeter check on each battery will prove or disprove.

Multimeter - Engine battery 12.41 Leisure Battery 12.36. Not massively different.

Put the EHU on now.Will leave it on for a day or two and see what happens.

 

[autorouter]

The motor home manual says 'when attached to the EHU the engine battery and the leisure battery are automatically charged by the charging unit on the transformer/rectifier. The starter battery is only charged with a float charge. The charging current is adapted to suit the condition of battery. The ensures it is not possible to overload the battery.'

If you look on the EBL front you will see the symbol 'IUoU'. This indicates it is a 3-stage intelligent charger.
I = Bulk charge, Uo = Absorption charge, U = Float charge.

Charging a lead-acid type battery is quite inefficient - to put 50Ah of charge in, you need to supply 70Ah, and 20Ah is wasted. Lithium is better - 50Ah in requires a supply of 55Ah.

The last bit is a mistranslation from German. Battery charging in German is 'ladung', literally loading, but in English it's always called charging. So it means it is not possible to overcharge the battery.

 

[Bessy765]

I have a 2019 Iexo 736, try with the ehu off unplug the large and small fuses by the battery wait a couple of mins then put back in. My panel will sometimes only read 92% even after being on hook up for a week, when parked up not being used. Find doing this batteries will come up to 100%.