What’s a UB and an IB battery?

[colinallcars]

Thread title should have ‘reading’ at the end.

I was checking the voltage of my battery as it’s the original, getting on for ten years old. Stop / start is not cutting in (which is fine) but suggested the battery might be failing. Seems OK at 12 volts engine off, 14 volts engine running and the car starts fine but with the benefit of stop / start not cutting in so I’ll leave it meantime. That shows against UB, what is IB?

 

[Neiltodd]

Do you have a secondary battery in the car? (Most stop/start runs off the auxiliary battery)

 

[Ted]

Battery voltage and battery current. - would indicate a discharge.

‘I’ is the standard way to denote current.

 

[Larkone]

Battery voltage and battery current. - would indicate a discharge.

‘I’ is the standard way to denote current.

It also has a A (amps) not V (voltage) after the number

 

[ALFAitalia]

Seems OK at 12 volts engine off

12 volts is far from ok....it's less than 50 percent charged...so pretty flat. A fully charged battery should show 12.6 volts plus about an hour after switching the engine off....to allow time to settle after being charged by the alternator.

 

[190]

Using the in-car display is largely a waste of time as far as assessing a batteries state of charge is concerned. To do it properly the battery needs to be rested to dissipate the surface charge and the car needs to be asleep. You can't meet either of those conditions using the cars dashboard display.

Leave the car switched off for several hours or overnight, then use a digital voltmeter to measure the battery voltage under the bonnet. Compare your reading with the above table.

 

[colinallcars]

12 volts is far from ok....it's less than 50 percent charged...so pretty flat. A fully charged battery should show 12.6 volts plus about an hour after switching the engine off....to allow time to settle after being charged by the alternator.
View attachment 132606

Thanks, perhaps a new battery is in order before winter sets in. Though I intend to keep it for a few more years, it’s the last battery I’m likely to buy for this car so I might as well get the benefit of it.

 

[richard]

The stop-start will look at the charge rate of the battery (and lots of other stuff like outside temperature etc), and if it is taking lots of charge stop start will not work. I.e it wants a well charged battery (which is when the charge rate drops).
Xentry would tell you why Stop Start isn't "enabled' but its often easier / cheaper to just replace the battery, especially if the battery is more than 4 years old, and yours is much older!

I always say this: Remember disconnect negative (which may be an unexpected colour) fully, then positive. Then fit positive back, fully tighten and fit the red terminal cover, and then do the negative. Dont touch the +12 once the negative is connected because if your spanner touches the body you have a big issue !

R

 

[colinallcars]

New battery fitted and all is well. stop/start is working again which is a minor inconvenience and I now have confidence it will start on cold mornings throughout the winter.
Got a Varta F21 80 Ah from Tanya’s eBay shop for £133 with next day delivery. As I mentioned on another thread, this isn’t the battery that the vehicle search facility suggests but it is what was fitted in the factory.

 

[Muckypaps]

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