How conclusive is a Halfords battery test

paulhelenwilko

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Having issues with the starter battery requiring a jump start after only 2-3 weeks in storage. So unsure if the solar is not topping up the battery or if it’s on it’s way out.

So popped into Halfords for a free battery test. The tester said the battery was fine just needed a good run. It just struck me how quick this test was, what can the tester measure apart from Voltage and whilst the battery is still connected ?

Can I be sure that the battery is ok and I need to look elsewhere for the problem?

Paul
 
Not bad lasting 2/3 weeks, a good charge or run required.
I changed mine last week as was falling sitting overnight.
Trade price for a magic eye sealed 019 starter battery £69
 
Having issues with the starter battery requiring a jump start after only 2-3 weeks in storage. So unsure if the solar is not topping up the battery or if it’s on it’s way out.

So popped into Halfords for a free battery test. The tester said the battery was fine just needed a good run. It just struck me how quick this test was, what can the tester measure apart from Voltage and whilst the battery is still connected ?

Can I be sure that the battery is ok and I need to look elsewhere for the problem?

Paul
I took a battery back to Alpha batteries and they did the proper discharge test on the battery, no fault found, problem was with my battery terminals and ignition switch.
 
previous winters the battery has never gone flat in storage. The solar was set to trickle the starter battery, but a couple of years ago we had a b2b fitted ( Votronic VCC1212-50) and since then the starter battery has been lower when fetched from storage. The leisure batteries are always full.

When I queried this Roadpro said that

'The new Votronic DC-DC charger installed has a pulse charge for maintenance on the starter battery'

Should this be keeping the starter battery topped up whilst in storage ?

Paul
 
Our little fiesta will sit for four months and still start it when we get back from travels ,
There’s normally a removable sticker that gives you the battery date ! Have a look at that and if it’s more than four years old I’d be getting a good replacement and not from halfrauds
I leave them to the last days, 10 years in my car before a new one was got, same with the van battery last week.
 
Do they still use the big device like this 1712816773531.png

which puts a simulated load on the battery, a voltage test tells very little unless it reads low, 12v+ doesn't tell you if it'll start or just run the radio.
 
Can anyone answer the question:

The B2B (Votronic VCC1212-50) has a pulse charge for maintenance of the starter battery, but is this working while in storage? Ie taking power from the leisure batteries or solar to keep the starter battery charged.
 
Can anyone answer the question:

The B2B (Votronic VCC1212-50) has a pulse charge for maintenance of the starter battery, but is this working while in storage? Ie taking power from the leisure batteries or solar to keep the starter battery charged.

Yes it will. Providing the A-B switch is set to B and there is a mains charger or sufficient solar power charger connected to the house battery side.
 
Search the older posts on this subject.
Garage battery testers are a waste of time for a motorhome battery.
It's just for checking if it can handle starting the engine, you probably know this already.
A capacity test takes much longer, but is very simple to do.
Find the older post for an explanation.

Mark
 
Having issues with the starter battery requiring a jump start after only 2-3 weeks in storage. So unsure if the solar is not topping up the battery or if it’s on it’s way out.
Solar is probably not topping up the starter battery: few do. 2-3 weeks of storage might be enough to run down a good battery, depending on how much power is used in the background (alarm, tracker, ecu, radio memory etc etc)

So popped into Halfords for a free battery test. The tester said the battery was fine just needed a good run. It just struck me how quick this test was, what can the tester measure apart from Voltage and whilst the battery is still connected ?

Can I be sure that the battery is ok and I need to look elsewhere for the problem?

Paul
This test does measure one aspect of a battery, and can flag up a serious problem. Fail this test and a starter battery is due for replacement.

Note that this test is not suitable for a habitation battery, and failing this test should not write off a habitation battery.

However, a battery can pass this test and still be no use at all. So, no, you can't be sure that the battery is OK.

A starter battery has to accept a large quantity of power. It has to store that power. It has to deliver that power at a high current for a short time (to run the starter) and lower current for a longer time (lights, ignition etc).

The three main faults that can appear in a battery are:

1. The battery's capacity can fall. This normally happens gradually, but some faults make it happen quickly.

2. The battery's ability to store the power can be impaired by faults in one or more of the cells.

3. The internal resistance of the battery can rise. This will undermine its ability to provide a high current to the starter.

Basically, the tester only measures the battery's ability to provide a hefty starting current. That's basically a matter of measuring its internal resistance under load.

Years ago, this was done using a metal strip effectively almost short-circuiting the battery and measuring the voltage under that load.

Because this test would finish off a fading battery, and because it was extremely dangerous to the operator (flammable gases, large sparks and corrosive acids don't go well with human faces), this sort of tester is no longer used.

Nowadays the thing that looks like a multimeter does more or less the same thing, but it only takes the high current for an extremely short time, and not until after the connections are securely made.
 
Solar is probably not topping up the starter battery: few do. 2-3 weeks of storage might be enough to run down a good battery, depending on how much power is used in the background (alarm, tracker, ecu, radio memory etc etc)


This test does measure one aspect of a battery, and can flag up a serious problem. Fail this test and a starter battery is due for replacement.

Note that this test is not suitable for a habitation battery, and failing this test should not write off a habitation battery.

However, a battery can pass this test and still be no use at all. So, no, you can't be sure that the battery is OK.

A starter battery has to accept a large quantity of power. It has to store that power. It has to deliver that power at a high current for a short time (to run the starter) and lower current for a longer time (lights, ignition etc).

The three main faults that can appear in a battery are:

1. The battery's capacity can fall. This normally happens gradually, but some faults make it happen quickly.

2. The battery's ability to store the power can be impaired by faults in one or more of the cells.

3. The internal resistance of the battery can rise. This will undermine its ability to provide a high current to the starter.

Basically, the tester only measures the battery's ability to provide a hefty starting current. That's basically a matter of measuring its internal resistance under load.

Years ago, this was done using a metal strip effectively almost short-circuiting the battery and measuring the voltage under that load.

Because this test would finish off a fading battery, and because it was extremely dangerous to the operator (flammable gases, large sparks and corrosive acids don't go well with human faces), this sort of tester is no longer used.

Nowadays the thing that looks like a multimeter does more or less the same thing, but it only takes the high current for an extremely short time, and not until after the connections are securely made.
Thankyou for the detailed reply.
 
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