What kind of multimeter do I need to do an engine battery test?

[GeeCee]

I'm thinking of buying a multimeter to do a battery test on my engine battery to see what's causing it to lose power 3 days after charging, i.e. by testing the power being drawn and pulling out fuses to identify the culprit.

Looking online it seems you can pay anything from £8 to £160. Some of the cheaper multimeters seem to have a maximum of 10 amps (assuming I've understood their purpose correctly) but some of the fuses on the Fiat are for 20 amps. Can someone recommend one that covers 20 amps at a reasonable price, e.g. up to say £50.

 

[autorouter]

The OP's is fine for DC current.

This is mine which is identical to the OP's and measures DC current.

Note that max DC current is 10 Amps, but you can test any rating (20 amp, 50amp etc.) of fuse for continuity after removing the fuse because the only current passing through the fuse will be the small current from the meter's own internal battery.

Yes you're right, standard (ie non-clamp) multimeters usually all measure DC current.

There's a mistake in the instructions for measuring Amps. It should read 'To test current (Amps) move red probe to here.' The black probe stays in the COM socket, that's why it's called COMMON. The red probe moves to the '10A' socket to measure using the 10A range. This is yet another reason why I prefer clamp meters.

 

[pappajohn]

You really don't want to be messing about removing fuses from the battery connections in a modern vehicle I wouldn't risk it with all the ECU's that love throwing wobbles.
I use a U210E clamp meter as well got to be the best 30 quid I ever spent.

I was referring to the fuse box, not the battery fuses
So if a fuse blows it causes no end of problems with that circuit.
Quick, take all fuses out and replace with 50a ones so they don't blow.

 

[Spriddler]

There's a mistake in the instructions for measuring Amps. It should read 'To test current (Amps) move red probe to here.' The black probe stays in the COM socket, that's why it's called COMMON. The red probe moves to the '10A' socket to measure using the 10A range. This is yet another reason why I prefer clamp meters.

Yep, my mistake - I was evidently concentrating too much on adding the text to the photo.
I've removed my photo from my post to save causing confusion.

 

[Gromett]

A youtube channel I follow just posted this video. I haven't watched it yet. BUT he is an excellent mechanic and diagnostician. Always worth a watch.

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[GeeCee]

Great but easy for a novice with electrics to make a mistake. In the OP the desire was to measure current draw to see what’s flattening battery. The right thing to buy was a current clamp….

Well my original plan was to use the method described in this video about parasitic battery drain. And as I understand it from the video I can do this without the need for a clamp. However the method of testing described earlier by papajohn about testing the current passing through the fuses seems better as I won't need to be trying to look at the battery draw with the meter remote from the fuses. True I am a novice with electrics and a mulimeter. Happy to take any sound advice.

My initial plan was to go to a garage and get them to do a battery test, but the garages near me can't fit an 8m motorhome on their premises. And I don't want to go to my nearest Fiat Professional dealer as they can't be trusted to do anything properly from past experience. So I've resorted to DIY.

 

[Gromett]

Just watched it. Not overly helpful to the OP's question.

BUT. He did point out how to correctly connect a multimeter inline to avoid the surge blowing the meter.

 

[Gromett]

GeeCee

South Main auto do get regular battery drain issue in as you might expect and he has done quite a few videos. This was perhaps not the most helpful to you.

But you should check out the others. He really is a fantastic teacher as well and you will learn a lot from watching them.

https://www.youtube.com/@SouthMainAuto/search?query=battery

 

[GeeCee]

Further to all the above I've done a parasitic battery drain test using the multimeter. I didn't find readings other than zero at all the fuses. And I did turn the radio on to make sure I did get a positive reading which I did for that fuse. So now I'm thinking it's the battery that's at fault. From what I can see getting the battery out is not just a case of disconnecting the + and - terminals. There's loads of connections to the battery, so two further questions:

1. what's the minimum I need to disconnect to get the battery out?
2. will I be able to get a replacement battery at Halfords, or is it more of a specialist battery I need?

 

[Richard n Ann]

Further to all the above I've done a parasitic battery drain test using the multimeter. I didn't find readings other than zero at all the fuses. And I did turn the radio on to make sure I did get a positive reading which I did for that fuse. So now I'm thinking it's the battery that's at fault. From what I can see getting the battery out is not just a case of disconnecting the + and - terminals. There's loads of connections to the battery, so two further questions:

1. what's the minimum I need to disconnect to get the battery out?
2. will I be able to get a replacement battery at Halfords, or is it more of a specialist battery I need?

View attachment 707170

I"m ordering one of these before the next trip. The existing one will be 9 years old in July.

S4 013 Bosch Car Battery 12V 95Ah Type 019 S4013

S4 013 Bosch Car S4 Battery Bosch Group are one of the leading battery manufacturer companies in the world and have been delivering quality German engineering in the automotive industry for more than 100 years! Bosch is a world renown company name that have and still are leading the way for many...

www.tayna.co.uk

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[Richard n Ann]

what's the minimum I need to disconnect to get the battery out?

Just disconnect the posts and pull the gubbins away and to the side. I've made a connector for mine so I can connect the old car battery up to keep all the vans electrics powered up ie air bag ECU

 

[Diabalo]

GeeCee Just remove the Pos and Neg terminals, all the other connections come off with them.

 

[Gromett]

Further to all the above I've done a parasitic battery drain test using the multimeter. I didn't find readings other than zero at all the fuses. And I did turn the radio on to make sure I did get a positive reading which I did for that fuse. So now I'm thinking it's the battery that's at fault. From what I can see getting the battery out is not just a case of disconnecting the + and - terminals. There's loads of connections to the battery, so two further questions:

1. what's the minimum I need to disconnect to get the battery out?
2. will I be able to get a replacement battery at Halfords, or is it more of a specialist battery I need?

View attachment 707170

That big plate on the positive side should come off in one chunk.

The grey lever on the negative terminal may be replicated on the positive terminal in which case it will be easy just to flick both levers and pull them off.

 

[Gromett]

Further to all the above I've done a parasitic battery drain test using the multimeter. I didn't find readings other than zero at all the fuses. And I did turn the radio on to make sure I did get a positive reading which I did for that fuse. So now I'm thinking it's the battery that's at fault. From what I can see getting the battery out is not just a case of disconnecting the + and - terminals. There's loads of connections to the battery, so two further questions:

1. what's the minimum I need to disconnect to get the battery out?
2. will I be able to get a replacement battery at Halfords, or is it more of a specialist battery I need?

View attachment 707170

Looking again probably not a quick release on positive side. Just get a socket onto the nut on the positive terminal of the battery itself. Don't try to disconnect anything on the big plate.

 

[TDub49]

Before you go to the lengths of replacing the battery, have you disconnected the earth strap and thoroughly cleaned the end where it connects to the bodywork and made sure that the clamp is really tight? If it is the battery, as others have said, straightforward undo the nut on the +ve terminal and unclip the -ve, it will all lift off. Order your battery from Tayna, overnight delivery and great products/prices.

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[GeeCee]

Thanks for all the above comments. That's what I was hoping for, something simple and straightforward.

 

[GeeCee]

Just disconnect the posts and pull the gubbins away and to the side. I've made a connector for mine so I can connect the old car battery up to keep all the vans electrics powered up ie air bag ECU

What are the implications of not having the electrics powered for a brief period of time. I expect I'll need to put in a code for the radio to get that working again, but wasn't expecting anything else to fail.

 

[Gromett]

What are the implications of not having the electrics powered for a brief period of time. I expect I'll need to put in a code for the radio to get that working again, but wasn't expecting anything else to fail.

I suspect your best source of information on that front is the owners manual. Well worth a read anyway for the correct procedure.

 

[Richard n Ann]

What are the implications of not having the electrics powered for a brief period of time. I expect I'll need to put in a code for the radio to get that working again, but wasn't expecting anything else to fail.

The air bag ECUs are prone to failure and the error code is usually related to under or over voltage. So just a precaution really, won't hurt anything to do it.

 

[Spriddler]

When I have been anxious about removing a battery (e.g. unknown radio code) I connected a second battery with flying leads and croc clips before disconnecting the one to be be removed or tested.

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[stevec]

I've just changed my battery (Fiat Ducato 2015 - airbag ECU fault!). I left everything off for 30 minutes before removing it (I entered via the hab door). The negative clamp was easy although a little tight for my weak fingers! The positive need the two screws removing that hold the red clip. These hold the whole positive assembly to the battery. I used a spanner to loosen the nut at the post and a flat blade screwdriver to ease apart the clamp. At this point it's easy to free off the positive clamp? NO! The clamp digs into the soft material of the post and needs a bit of persuasion from underneath to lever it off. I used one leg of a bearing puller but you may need to improvise something if the clamp doesn't release. Also try to isolate the negative terminal so the earth lead doesn't flap down and make intermittent contact. You ill also need to be careful of the vent tube on the side of the battery. Best to remove before taking the battery out as the elbow connector into the battery is brittle and could snap. Mine did and I had to cobble together a repair. It's a heavy battery so be careful removing and refitting. I bought a Lucas battery from Tanya.

 

[Lenny HB]

What are the implications of not having the electrics powered for a brief period of time. I expect I'll need to put in a code for the radio to get that working again, but wasn't expecting anything else to fail.

When reconnecting the battery leave it 15min before turning on the ignition, then turn on the ignition for 5 min then off and leave for 10min before trying to start or anything else.

 

[Lenny HB]

will I be able to get a replacement battery at Halfords, or is it more of a specialist battery I need?

Get a Halfords Trade Card, apply online & pick up in store, you get around 25% discount on batteries.
For my van I got a Yuasa 5000 from them it was cheaper than Battery Mega Store with the Trade Card discount.

 

[dunnah01]

You'll also need to undo those 2 self tappers on the broken red tab on the +ve terminal to remove the whole clamp assembly

 

[GeeCee]

I"m ordering one of these before the next trip. The existing one will be 9 years old in July.

S4 013 Bosch Car Battery 12V 95Ah Type 019 S4013

S4 013 Bosch Car S4 Battery Bosch Group are one of the leading battery manufacturer companies in the world and have been delivering quality German engineering in the automotive industry for more than 100 years! Bosch is a world renown company name that have and still are leading the way for many...

www.tayna.co.uk

The one that's in is a Varta 80 Ah 700 A. The one you've listed is 95 Ah. Does it matter (I'm totally ignorant on electrical matters).

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[Gromett]

You'll also need to undo those 2 self tappers on the broken red tab on the +ve terminal to remove the whole clamp assembly

I don't think you do. They appear to be screwed to the plate not to the battery. Who would screw into a battery? Unless I am misunderstanding something here?

 

[Gromett]

The one that's in is a Varta 80 Ah 700 A. The one you've listed is 95 Ah. Does it matter (I'm totally ignorant on electrical matters).

You want one that has the same or better AH. But it is the CCA or Cold Cranking Amps that matter the most.
ensure you get one with a very good CCA rating. I try for 900A when I am buying but probably not necessary to go that far.

Oh and don't disregard physical size. Very very important.

 

[autorouter]

I don't think you do. They appear to be screwed to the plate not to the battery. Who would screw into a battery? Unless I am misunderstanding something here?

Many batteries have provision for this terminal. Because it's so big, with heavy cables, there would be a lot of strain on a battery post. The terminal can be held down by the two self-tapping screws to take some of the strain. Obviously the self-tappers should go into the holes provided for them, not just at random into the battery cover.

The one that's in is a Varta 80 Ah 700 A. The one you've listed is 95 Ah. Does it matter (I'm totally ignorant on electrical matters).

Sorry, I've lost track of which battery it is. If it's the starter battery the important figure is the '700A' for powering the starter motor, so that's a minimum, bigger is better. If it's the leisure battery the 80Ah figure is more important, and again bigger is better.

 

[Gromett]

Many batteries have provision for this terminal. Because it's so big, with heavy cables, there would be a lot of strain on a battery post. The terminal can be held down by the two self-tapping screws to take some of the strain. Obviously the self-tappers should go into the holes provided for them, not just at random into the battery cover.

Oh. I have NEVER seen those holes on a battery or on the plate. Interesting.


Just spent a few minutes looking at batteries on google images. some seems to have holes in that location but a lot don't. The ones that do appear to use it to hold the terminal shipping covers on?

If this is required then I suspect the OP will need to check if the battery has these?

Everyday is a school day

 

[Reallyretired]

I have a multitude of meters but a useful one I bought has a plug that fits a fuse holder and a digital ammeter on a short lead. You can remove the fuse and put it in a socket on the tester so the circuit is still fused, plug into the fuse holder and get a direct reading of current. 1 paid £12 from ebay but it has now gone up to £14.
It does the same ss using an ordinary meter with the plus that the circuit is still fused and it stays connected while you switch things on and off.

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[cyberyacht]

When reconnecting the battery leave it 15min before turning on the ignition, then turn on the ignition for 5 min then off and leave for 10min before trying to start or anything else.

Lenny HB You wouldn't need to do all that though if you connected another (smaller) battery with temp leads whilst doing the change would you? Incidentally, could you use the "jump start" connections for the temp battery which would make life simpler?