Allowable volt drop

[Ross365]

https://www.hioki.com/global/learning/usage/resistance-meters_2.html explains how they do it, although that page isn't specifically for lead acid batteries.

Ye olde drop tester isn't an accurate method of testing a lead acid battery. You can tell far more about the health of a battery from it's internal resistance, than you can from a brief drop test.
I can't even remember the last time I carried out a drop test, as the electronic tester gives far more accurate results, and any battery warranty claim has to be backed up with a test carried out by a digital tester. The cheap testers do tend to only give you a current estimated capacity and charge level, whereas the more expensive testers usually have vehicle/battery manufacturer specific features for generating battery test codes, and presets for various battery sizes/types.

Yes, the olde tester just imposes a heavy load and measures the voltage under that load, but they have been in use for a very long time and very often, will "sort the wheat from the chaff". An accurate measurement of internal resistance may well be a much better measurement, but given a choice between a cheapy electronic tester and a cheapy load (drop) tester, I'll take the latter; you can see and understand what you've got.

 

[zzr1200]

https://www.hioki.com/global/learning/usage/resistance-meters_2.html explains how they do it, although that page isn't specifically for lead acid batteries.

Ye olde drop tester isn't an accurate method of testing a lead acid battery. You can tell far more about the health of a battery from it's internal resistance, than you can from a brief drop test.
I can't even remember the last time I carried out a drop test, as the electronic tester gives far more accurate results, and any battery warranty claim has to be backed up with a test carried out by a digital tester. The cheap testers do tend to only give you a current estimated capacity and charge level, whereas the more expensive testers usually have vehicle/battery manufacturer specific features for generating battery test codes, and presets for various battery sizes/types.

The reason electronic reader are required for warranty is they have a print out, that states it's a half decent battery possibly, unfortunately the electronic testers "CAN'T" do a proper drop volt test under load because the circuitry JUST ISN'T UP to carrying 300+amps. So they only provide a snapshot of the batteries condition but not under NORMAL STARTING LOAD conditions, hence the old fashioned drop volt tester wins hand down.

We all know that come the end of October (for some earlier, M_C?) it's time to listen out for the duff battery that just hanging on to life and the cold and thicker oil will KILL IT...so get the wallet out...

 

[m_c]

An electronic tester is used because it's far more accurate.
If car manufacturers thought a drop test was a good enough indicator, they could quite easily achieve it through a cranking voltage test done using their own diagnostic kit.

I've seen many batteries pass a conventional drop test, yet fail a digital test, while I've only ever seen a single one pass a digital test yet fail on a drop test.
Those that have passed a drop test, are the ones that have given continual longterm starting issues.

 

[p0689109]

My old dial style battery tester has a heat sink which is used to check the cca of the battery. Normal use is for voltage readings and the current reading requires the switch to be held to show indication. The cca test is the more accurate way to prove the batteries condition. I have seen batteries showing 12+ volts after charge but sadly fail the current check!

 

[highseas]

Testers, v drop under load ect ect
Battery is crap one day, shout at the wife for leaving lights on and jump start if the same battery is crap the next day apologise to said wife and buy It a new battery.

Or park on hill

 

[Ross365]

An electronic tester is used because it's far more accurate. If car manufacturers thought a drop test was a good enough indicator, they could quite easily achieve it through a cranking voltage test done using their own diagnostic kit.

But I think that you are talking about "professional grade" electronic testers, which I suspect cost a lot of money, as distinct from some cheap thing off ebay. Anyway, I've managed with my drop tester for 40 years, so think it will see me out.

 

[Justme]

Well, I don't suppose, by any remote chance, you can explain how such a cheap device can measure a battery's CCA, handling a current of 100's of amps? I think that's a test you'd need a well-equipped laboratory specialising in car batteries to do. A plastic box with flashing lights means nowt - remember those two guys who went to jail for selling "explosive detectors" which could not actually detect a "bottom burp"?

They dont measure current at all.
Its not measuring the AH which would need a long discharge test.

Its measuring the CCA.

They test resistance & capacitance with voltage.

Have you never seen a battery tested at a parts shop?

They dont use drop testers anymore (well the ones I use dont).

For a cheap one

https://www.amazon.co.uk/ULTRAOBD2-Battery-Analyzer-Automotive-Motorcycle/dp/B07S2LB27F/ref=sr_1_6?crid=183IPUFTFQ9IU&keywords=battery+cca+tester&qid=1641488591&sprefix=battery+cca+tester%2Caps%2C537&sr=8-6

Or a better one

https://www.amazon.co.uk/Electronic-Battery-System-Tester-Printer/dp/B01FTMM4ES/ref=sr_1_1?crid=183IPUFTFQ9IU&keywords=battery%2Bcca%2Btester&qid=1641488667&sprefix=battery%2Bcca%2Btester%2Caps%2C537&sr=8-1&th=1

 

[Justme]

That green light indicates the charge of the battery in specific gravity and the fluid level in it's measuring vicinity is correct. It doesn't state the capacity in the battery, or weather it has a collapsed cell. Unfortunately the only way to determine that is to load test.


These testers are quite cheap (I have one) and do a superb job. You need to understand the results you get from the meter, but it is not rocket science

The green floating ball is only in one cell so it not much use if one of the other cells is faulty.

 

[quench]

With anything “modern” the brown out voltage is what will stop it from working, basically the electronics says no, so no spark, no fuel
The rule of thumb i use, is if battery voltage drops to 10v (on charged battery). i will be replacing battery
No point in waiting for it to completey fai, as invariably, they fail on a cold dark night, miles away from civilisation

 

[sg66]

If that's constant resting voltage it's almost dead, replace it.

 

[8ob]

My old dial style battery tester has a heat sink which is used to check the cca of the battery. Normal use is for voltage readings and the current reading requires the switch to be held to show indication. The cca test is the more accurate way to prove the batteries condition. I have seen batteries showing 12+ volts after charge but sadly fail the current check!

True, it normally shows up a duff one, the tester below is a tad kinder because you can dial in/adjust the load.

Bob

 

[nickk]

@ . 2010 transit,so common rail,don’t know wether there’s other electronics.
Having fitted the new ,and best of the original pair,it’s no different,one click on turning the key,same as the original state that caused me to replace the battery.
I’ve ordered a battery for the key fob and tomorrow I’ll check fuses ,can’t find any visible,loose connections.
Is there a way of testing the starter without removing it?

 

[m_c]

Key fob battery will make no difference to a transit.
As long as the key is recognised in the ignition, the immobiliser system is fine. It's only of the red immobiliser light flashes rapidly, you have a problem.

Is the click more of a dull thud from the engine area, like the starter trying to engage?
It most likely is the starter motor, but worth checking that the main earth to the engine (goes under one of the starter motor bolts), and the starter motor is still getting battery power when activated.
Starter is a bit awkward to get on RWD as the connections are a bit tight to get to. FWD is easy, as everything is at the front.

With the starter motor off, check to see if the nose has any metal fillings in it.
If it has, the dual mass flywheel is likely to be starting to fail, meaning a new starter motor is likely to fail quite quickly (any warranty claim on a starter will be rejected, if they find any metal filings), however it could last for years before giving any real problems depending on how much you actually use the van.

 

[nickk]

Key fob battery will make no difference to a transit.
As long as the key is recognised in the ignition, the immobiliser system is fine. It's only of the red immobiliser light flashes rapidly, you have a problem.

Is the click more of a dull thud from the engine area, like the starter trying to engage?
It most likely is the starter motor, but worth checking that the main earth to the engine (goes under one of the starter motor bolts), and the starter motor is still getting battery power when activated.
Starter is a bit awkward to get on RWD as the connections are a bit tight to get to. FWD is easy, as everything is at the front.

With the starter motor off, check to see if the nose has any metal fillings in it.
If it has, the dual mass flywheel is likely to be starting to fail, meaning a new starter motor is likely to fail quite quickly (any warranty claim on a starter will be rejected, if they find any metal filings), however it could last for years before giving any real problems depending on how much you actually use the van.

The click comes from the battery area,I think,or possibly the dash,I’ll listen more carefully tomorrow am.
The starter did attempt to turn when I tried to jump it,plus ,I replaced it 5 years/20,000miles ago.

 

[m_c]

Ah.
Is the click when you first turn the ignition on?
If it is, then that's normal. It's the main relay powering up that links the two batteries.

If there's no unusual (or lack off) lights showing on the instrument cluster, next would be to check power at the engine.
Try jump leads directly on to the engine, and the jump start point.

Is it FWD or RWD?
FWD were bad for the main earth lead failing at the starter motor, along with the main positive cables.
RWD were generally better, but I have seen an occasional one fail.

 

[p0689109]

I have two of the type I mentioned in my first post. The one I use is analogue and the second is electronic which I find is not as good or accurate as the good old mechanical one. It is satisfying to see the needle move across the dial. or at least I think so.

 

[Ross365]

True, it normally shows up a duff one, the tester below is a tad kinder because you can dial in/adjust the load. Bob

Ooooh, that does look like a nice piece of kit, never seen one like that before! Who is the maker please? I've seen adjustable carbon pile devices that can handle a few watts before, but that must be a monstrous device!

 

[R Kraft]

I think 8 volts is too much of a drop, modules coming on line at 8 volts will register a fault, even 9.5v is a bit too much of a drop,

I had a car that would crank for a long time but wouldn't start.
The battery was putting out 9V cranking ,and at 9V the ignition module was inert.

 

[zzr1200]

Ooooh, that does look like a nice piece of kit, never seen one like that before! Who is the maker please? I've seen adjustable carbon pile devices that can handle a few watts before, but that must be a monstrous device!

https://www.amazon.co.uk/Solar-1874-Invasive-Load-Tester/dp/B014T7HL3I?th=1

 

[nickk]

Yes I hear the relay clicking in by the battery,350a fuse !
I ran a jump lead from the battery to the cylinder head lifting eye,it started immediately,yippee,then removed it and it started 3 times in succession,anyway figured a coincidence,so removed the earth cable from the starter to chassis,wire brushed everything,ground the paint off at the chassis thread hole,refitted and sealed with heavy grease,cleaned the positive terminal on the starter,new nut and copper washer.
Will drive around with a jump lead in the back. Thanks all.