Batteries dead?

[Yondo]

I am wondering if my leisure batteries are dead.

I have put my T6 on plug hookup yesterday at 17h and took it off next day that 12h. It showed 12.7v and 90% (almost always drops to 90% immediately).

At 19h I put the fridge on max as a test for the batteries. It showed -4a and was still at 90%. At 23h I checked up on the camper and heard the fridge still buzzing. Looked at the display and it showed 11.2v and 90%.

Opened the fridge to feel if it was cold and it stopped buzzing. Fridge was cold though (4°c).

As far as I have read the fridge shouldn't have been running at 11.2v because it shuts off at that point?
It is also weird to me the displays shows 11.2v but still 90%? Is it normal a battery drops voltage when running fridge etc.?

Are my batteries dead? Or do I have a different problem?

 

[Steve1]

It definitely sounds like one or both of your batteries have a problem. They should definitely last much longer than that before reaching 11.2V. When they were on charge before unplugging you should have seen them reach over 14V first then if that happens then charger will shut down to something like 13.2V and trickle them continuously. So put on charge and see if that happens first to see if they fully charged in the first place.

 

[Yondo]

@Steve1 thanks for the anwer.

Yesterday at 23h I turned off the fridge and left it. We only charged 2 phones and the battery went to 10% really quick.

Put it on charge again and now, when actively charging, it get 13,7v. Very rare that I see 14v. When it was trickle charging yesterday morning it was around 13,2v. And when I unplugged it showed 12.7v 100% but it always drops to 90% in first 5min when using no electricity.

Could it be the 75a fuse on the back battery? How do I check this fuse?

What is the expected behaviour between voltage and amps when using fridge? Is it expected the voltage drops or should it only drop as the battery is being drained?
Because now it drops around 1v when I put in fridge, even when at full charge.

 

[Yondo]

@Steve1 thanks for the anwer.

Yesterday at 23h I turned off the fridge and left it. We only charged 2 phones and the battery went to 10% really quick.

Put it on charge again and now, when actively charging, it get 13,7v. Very rare that I see 14v. When it was trickle charging yesterday morning it was around 13,2v. And when I unplugged it showed 12.7v 100% but it always drops to 90% in first 5min when using no electricity.

Could it be the 75a fuse on the back battery? How do I check this fuse?

What is the expected behaviour between voltage and amps when using fridge? Is it expected the voltage drops or should it only drop as the battery is being drained?
Because now it drops around 1v when I put in fridge, even when at full charge.

 

[dspuk]

@Steve1 thanks for the anwer.

Yesterday at 23h I turned off the fridge and left it. We only charged 2 phones and the battery went to 10% really quick.

Put it on charge again and now, when actively charging, it get 13,7v. Very rare that I see 14v. When it was trickle charging yesterday morning it was around 13,2v. And when I unplugged it showed 12.7v 100% but it always drops to 90% in first 5min when using no electricity.

Could it be the 75a fuse on the back battery? How do I check this fuse?

What is the expected behaviour between voltage and amps when using fridge? Is it expected the voltage drops or should it only drop as the battery is being drained?
Because now it drops around 1v when I put in fridge, even when at full charge.

There a lot going on in the posts but I think the answer is quite simple

Your batteries are not “dead” but it does sound as if they are quite old and have lost a bit of capacity. When were they last replaced? Is there a manufacturer date on them?

As such they are likely “fine” but could do with replacement if you wanted a few days off grid.

Ref the percent. @WelshGas can answer better for a T6 but if the % works the same way as the 6.1 then the % may mean % left at the point in time you are using the batteries. The 6.1 gives you hours but works the same way and goes up and down depending on the draw.

For the amps and volts question. It’s normal behavior for the amps to go into minus (the draw) as you are using something. Fridge. Lights. Chargers. It should go into the positive when driving and your alternator charging, or if you have solar. As a fridge gets to working temp the draw should reduce (to -1) as it’s now just ticking over.

As for volts. Yes your volts will go down. That is what is giving you the power to do things when not driving or on EHU.

 

[Yondo]

@dspuk Thanks for the explanation.

I think the batteries are still the original ones from 2016. And I think the previous owners did not take care for them very well.

 

[dspuk]

@dspuk Thanks for the explanation.

I think the batteries are still the original ones from 2016. And I think the previous owners did not take care for them very well.

While not unheard of 9 years for used and abused leisures might be pushing it a little.

As mentioned, your issues seem to be around the numbers rather than use. If they are not failing on you when camping then soldier on.

 

[Benji Boy]

I am wondering if my leisure batteries are dead.

I have put my T6 on plug hookup yesterday at 17h and took it off next day that 12h. It showed 12.7v and 90% (almost always drops to 90% immediately).

At 19h I put the fridge on max as a test for the batteries. It showed -4a and was still at 90%. At 23h I checked up on the camper and heard the fridge still buzzing. Looked at the display and it showed 11.2v and 90%.

Opened the fridge to feel if it was cold and it stopped buzzing. Fridge was cold though (4°c).

As far as I have read the fridge shouldn't have been running at 11.2v because it shuts off at that point?
It is also weird to me the displays shows 11.2v but still 90%? Is it normal a battery drops voltage when running fridge etc.?

Are my batteries dead? Or do I have a different problem?

 

[Steve1]

@Steve1 thanks for the anwer.

Yesterday at 23h I turned off the fridge and left it. We only charged 2 phones and the battery went to 10% really quick.

Put it on charge again and now, when actively charging, it get 13,7v. Very rare that I see 14v. When it was trickle charging yesterday morning it was around 13,2v. And when I unplugged it showed 12.7v 100% but it always drops to 90% in first 5min when using no electricity.

Could it be the 75a fuse on the back battery? How do I check this fuse?

What is the expected behaviour between voltage and amps when using fridge? Is it expected the voltage drops or should it only drop as the battery is being drained?
Because now it drops around 1v when I put in fridge, even when at full charge.

It does sound like one or both are pretty close to dead for that amount of drop in the time you said. In regards to voltage drop when the fridge is on Vs off, on a good battery only about 0.2V drop.

You can check the fuse on the rear battery by opening the compartment below the wardrobe in the boot and using a multimeter, set to volts and with the wires in the volts terminals, put the black on a screw which goes to earth and the red first on the top of the fuse going off the the wire, the directly on the battery terminal under the fuse. Both readings should match if the fuse is ok.

Another thing to check is to put the batteries back on charge for quite a while and feel if one or both are getting hot. If your batteries won't reach 14V or more then one is not charging properly and in this case it will normally get warm. You can touch the one under the seat but sliding it forward a little and the one in the back in the compartment in the boot again. This might give away which one has a problem. Batteries in good condition don't get hot when charging at the normal rate. Close to dead ones do.