Technical Van explodes & I learn something about my battery

[jnoiles]

Last night I was in traffic when a van exploded in front of me: http://www.youtube.com/watch?v=b_WMVC4PT1k&feature=youtu.be

Once the police had worked out that the boom was a gas cylinder and there were more in the van they moved us out a couple of blocks. I left my hazard lights on.

Later that night (midnight-ish) when I was finally able to return I discovered a dead battery. The AA attended and did a battery test. The battery had 2 dead cells. So I had it replaced.

Is there a way to test a battery at home, short of expensive diagnostic tools like the AA has? I've googled and nothing is coming up?

 

[loveshandbags]

Is there a way to test a battery at home, short of expensive diagnostic tools like the AA has? I've googled and nothing is coming up?

Battery tester, Silver style SS Tester, Hydrometer: Amazon.co.uk: Car & Motorbike
Amazon.com: E-Z Red S101 Battery Hydrometer: Automotive

Local Auto shop uses Hydrometer Battery tester or something similar

It was lucky there was no one was hurt in that blast.

 

[nemchenk]

Yeah, I hydrometer would do it, but IIRC many batteries nowadays are sealed, so you can't get to the cells anymore to sample the acid

 

[306maxi]

Yeah, I hydrometer would do it, but IIRC many batteries nowadays are sealed, so you can't get to the cells anymore to sample the acid

Yup.

 

[jnoiles]

The 500 is definitely sealed. I was thinking something more electronic gadgety rather than something that required me to open up a sealed unit.

 

[306maxi]

The 500 is definitely sealed. I was thinking something more electronic gadgety rather than something that required me to open up a sealed unit.

Well, I was watching wheeler dealers the other day (They were doing their mega mega mega mega light restoration on an inter) and Ed just used a multimeter across the terminals.

 

[jrkitching]

Well, I was watching wheeler dealers the other day (They were doing their mega mega mega mega light restoration on an inter) and Ed just used a multimeter across the terminals.

To meaningfully check a sealed lead-acid battery, you need to put it under a known specific heavy load & measure the voltage drop - just putting a multimeter across the terminals is next to useless.

 

[Andy Monty]

I have one of these not as accurate as the newer electronic fancy ones but it gives a good indication to the batterys condition...

clamp to battery terminals

look at scale and match up to the battery CCA and activate the toggle switch and hold for ten seconds watching the scale the needle will naturally drop to the left as you put the load on if it falls into the amber or red on the scale its on its way out if it stays in the green segment its "healthy"

 

[306maxi]

To meaningfully check a sealed lead-acid battery, you need to put it under a known specific heavy load & measure the voltage drop - just putting a multimeter across the terminals is next to useless.

Well, he had it idling and was looking for 14v across the terminals.

 

[Andy Monty]

just doing a very basic alternator test doesn't prove a lot other than the alternator is pushing out a voltage but on occasions it can do this if faulty but no amps thats where a DC amp clamp meter comes in ;-)

 

[306maxi]

just doing a very basic alternator test doesn't prove a lot other than the alternator is pushing out a voltage but on occasions it can do this if faulty but no amps thats where a DC amp clamp meter comes in ;-)

Sorry, I've been a complete idiot. He was testing whether the alternator was working properly, not the battery. Disregard everything that I've said

 

[RUI]

Disregard everything that I've said

We usually do

 

[loveshandbags]

The 500 is definitely sealed. I was thinking something more electronic gadgety rather than something that required me to open up a sealed unit.

Being meaning to reply to my 'boo boo' about suggesting a Hydometer. I had not realised the battery was sealed . Picture attached has a very similar battery as the one in the 500 and with removal cover it would be easy to confuse the 2. Note the quick release on the negative terminal connector which is very 'handy'.

I had an issue with what was called a 'Dry battery' - it was a Absorptive Glass Matt battery which was not supposed to be charged in the 'normal' way. So I had the pleasure of having it to push and 'jump in' when I left the lights on.

Note that the battery charger for a Sealed and a 'Flooded' battery (i.e. the traditional type) should have a switch selecting a lower charge for the former. The chargers that I have in the garage would damage the 'new' Sealed batteries.

Also I'm a little sceptical about the maintence free aspect of these Sealed batteries. Seeing some youtubes of US guys drilling holes in the top of batteries to a 'restricted' depth to 'maintain' them and then re-sealing them.

http://batteryuniversity.com/learn/article/how_to_restore_and_prolong_lead_acid_batteries
http://www.lesterelectrical.com/news/newsletters/2006feb01.PDF
http://www.pistonheads.com/gassing/topic.asp?h=0&t=485777


Flooded:
This is the traditional engine start, tractor and deep cycle style battery. The liquid electrolyte is free to move in the cell compartment. The user has access to the individual cells and can add distilled water as the battery dries out. Popular uses are engine starting and deep cycle designs.
Typical absorption voltage range 14.4 to 14.9 volts, typical float voltage range 13.1 to 13.4 volts.

Sealed:
This term can refer to a number of different constructions, including only a slight modification to the flooded style. In that case, even though the user does not have access to the cell compartments, the internal structure is still basically the same as a flooded battery. The only difference is that the manufacturer has ensured that a sufficient amount of acid is the battery to sustain the chemical reaction under normal use throughout the battery warranty period. Other types of lead acid batteries are also sealed, as explained below. Very popular uses are engine start and limited starting/deep cycle applications.
Typical absorption voltage range 14.2 to 14.7 volts, typical float voltage range 13.1 to 13.4 volts.

 

[frupi]

The 500 is definitely sealed. I was thinking something more electronic gadgety rather than something that required me to open up a sealed unit.

I personally use a Scangauge 2 which is permanently plugged into the car's OBDII port. Of the four readings I monitor on the gauge, battery voltage is displayed. Hangs around the 14v mark. It's just a good constant visual check when out and about in the car. Obviously it takes its info direct from the EMCU, so I'm assuming it's correct.

 

[jnoiles]

Interesting. It's just occurred to me that I have Fiat ECU Scan and a handful of other diag tools that came with the ELM reader. I need to have a play around with some of them, see if there is anything there that will indicate battery health in a meaningful way.

 

[TrevC]

I've had a couple of experiences of failed batteries over the years, where cells have failed open-circuit. I don't think any tester can anticipate that. In one instance, my car (FIAT 127!) had been starting fine, I got in it one morning and it turned over normally for about 2 seconds then stopped, and all the dash lights went out. A multimeter reading gave around 8V (2 cells gone) and a battery charger wouldn't put more than 500mA into it, therefore I assume the cells had suddenly failed high impedence.

 

[loveshandbags]

I've had a couple of experiences of failed batteries over the years, where cells have failed open-circuit. I don't think any tester can anticipate that. In one instance, my car (FIAT 127!) had been starting fine, I got in it one morning and it turned over normally for about 2 seconds then stopped, and all the dash lights went out. A multimeter reading gave around 8V (2 cells gone) and a battery charger wouldn't put more than 500mA into it, therefore I assume the cells had suddenly failed high impedence.

I would be in the same category and 'problems' arise if a car is left lying for a while and then gets a lot of 'cranking' to get the car started. I used to buy batteries in the local Motor Factors but then found myself going back for another battery 2 months after the 12 month warranty expired. When I was looking at the 'deals' in Halfords there were offering 3 years on their more expensive (I think it was Exide) and it seemed good value for money after what I had spent. Also some makes seem to need 'special' batteries and if you don't use the manufacturer's battery they sit too high. Had that problem with a 323i on the boot cover and it was of the 'Flooded' (normal) battery type. In hindsight it probably should have been a ATM since it was in a 'sealed' boot like the MX5. In my experience once the battery starts to go it's useless and can't be trusted.