What changed with vehicle batteries to make them maintenance free?

[mart]

Some years ago batteries (for cars at least) , were the type that periodically had to be topped up with distilled water. Then came along maintenance free batteries. But, what was it that exactly changed about the battery so that they longer needing to be topped up? I’m thinking it will be something more than just a sealed top to prevent evaporation?

 

[zx9]

Some reading http://en.wikipedia.org/wiki/Automotive_battery it would appear that the electrolyte is held in a gel or glass fibre, which together with modern regulated charging stops the electrolyte evaporating.

 

[JayRS4]

What changed is greed, they make it so you can't maintain and have to replace.

Not that I'm cynical or bitter at all

 

[MattF]

As zx says, they use a gel type solution now. Personally, I detest SLA's. The old style batteries are more robust, when maintained properly.

 

[gordon stephenson]

In the old days, a battery going duff would give weeks or even months of reduced service. You could nurse one along for ages before forking out for a new one. Now a days first hint you get is when it totally gives up overnight,

 

[mart]

Yes.After starting car, I drove 11 miles last night so bit of heat in engine at point of stopping even though not full operating temp. (2lt turbo diesel). Stopped to make an 8 min phone call. The outside temp was 5 degrees. Tried to start car to continue journey, no chance. Had to buy new battery this afternoon. 70Amp hrs. I remember in the 80s when the battery on a 5.3lt jag was only 44 amp hrs. I suppose there is much more going on electrically these days with vehicles.

 

[Cobbler]

In the old days, a battery going duff would give weeks or even months of reduced service. You could nurse one along for ages before forking out for a new one. Now a days first hint you get is when it totally gives up overnight,

You were able to use a starting handle when the battery was knackered, you knew if you could get it to last to the spring, it would go on until next winter. My brother broke his wrist when his Bedford CA kicked back, thumb the wrong side of the handle, we all took the P, telling him he was suffering from "cranker's wamp"

 

[colnerov]

Yes.After starting car, I drove 11 miles last night so bit of heat in engine at point of stopping even though not full operating temp. (2lt turbo diesel). Stopped to make an 8 min phone call. The outside temp was 5 degrees. Tried to start car to continue journey, no chance. Had to buy new battery this afternoon. 70Amp hrs. I remember in the 80s when the battery on a 5.3lt jag was only 44 amp hrs. I suppose there is much more going on electrically these days with vehicles.

Hi, diesels are harder to turn over than petrol, CR of 23:1 as opposed to 9:1. The battery is only there to start the car, once its running the alternator provides all the power and the batt plays no further part until it has to start the car again.

 

[Gavin_d]

Hi, diesels are harder to turn over than petrol, CR of 23:1 as opposed to 9:1. The battery is only there to start the car, once its running the alternator provides all the power and the batt plays no further part until it has to start the car again.

Not so true. Modern cars have systems running all the time while the car is parked and locked. Not a lot of drain but some. Keyless entry and stop start are good ones.

 

[wristpin]

Some time ago I read in a trade mag that we would soon see cars with 36 volt electrical systems to cope with "electric everything" including power steering and water pumps but it doesn't seem to have happened yet.
The current move to "stop start" engines to lower emissions must put quite a strain on batteries and charging systems.

 

[Wedg1e]

Hi, diesels are harder to turn over than petrol, CR of 23:1 as opposed to 9:1. The battery is only there to start the car, once its running the alternator provides all the power and the batt plays no further part until it has to start the car again.

Almost all modern vehicles have electronic fuel injection, whether petrol or diesel; the current drain of the starter motor knocks the available juice back to the point where the injection won't work on a failing battery - so you can't get the car to start for the alternator to take over!

 

[Wedg1e]

The current move to "stop start" engines to lower emissions must put quite a strain on batteries and charging systems.

I've been saying for a while, with my cynical head on, that whilst these systems might reduce the overall fuel consumption of a vehicle, any saving is likely to be offset long-term by the necessity to replace knackered starter motors and batteries - of course unlikely to be a problem for many typical owners who change cars every year or three but IMHO likely to be a major issue for later owners.
Nursy's car has start-stop; whenever I drive it I turn the damn thing off as soon as I get in.

 

[Gavin_d]

Almost all modern vehicles have electronic fuel injection, whether petrol or diesel; the current drain of the starter motor knocks the available juice back to the point where the injection won't work on a failing battery - so you can't get the car to start for the alternator to take over!

Renault scenic give a warning in the display of Injection fault when the battery is flat.

 

[Bill Edwards]

I've been saying for a while, with my cynical head on, that whilst these systems might reduce the overall fuel consumption of a vehicle, any saving is likely to be offset long-term by the necessity to replace knackered starter motors and batteries - of course unlikely to be a problem for many typical owners who change cars every year or three but IMHO likely to be a major issue for later owners.
Nursy's car has start-stop; whenever I drive it I turn the damn thing off as soon as I get in.

Ah, but aren't modern cars bought/sold on the stated MPG figure, the tax cost (based upon emissions) and zero thought given to the costs that result from all the gadgets that give the nice figures?

Looking at the cost of repairing all the emission stuff bolted to exhausts, or even just giving vehicles a good thrashing to clean them out, i'm then very skeptical about any actual cost savings.

 

[Cobbler]

On my Transit camper van, last winter, the battery was low when I tried to start it, so put a charger on to warm the battery a bit. After about 15 minutes tried again & it just got it going, but the alternator light came on though. Removed it & took it to the local repairers. He fitted a new regulator & said these smart alternators won't start charging if the battery voltage is low & it screws the regulator. He told me he gets loads to repair from the car sales forcourts where cars sit there for months. Apparently these alternators talk to the ECU & when you put your foot down they drop the charging rate to allow more power to the wheels. Is this progress when a flat battery knackers it?

 

[Robotstar5]

Some of the models we build have a 2nd, smaller battery fitted behind the rear quarter trim, must find out what it's used for.

 

[ukracer]

Some time ago I read in a trade mag that we would soon see cars with 36 volt electrical systems to cope with "electric everything" including power steering and water pumps but it doesn't seem to have happened yet.
The current move to "stop start" engines to lower emissions must put quite a strain on batteries and charging systems.

Ask renault and Honda! lol

 

[gordon stephenson]

Remember the Moscovitch(spelling) cars way back, I think Russian imports in the sixties. I had a mate that bought one. and the Very cold starting procedure in the handbook called for turning the headlights on for something like 10 minutes before attempting to hit the starter just to get the battery "warmed up a little"

 

[Wedg1e]

Anything with stop start has special batteries, known as the AGM (absorbed glass mat) type, more expensive but they are specced to something like 300,000 stops and starts, rather than the 20-30K of flooded lead acid cell batteries

...which is fair enough, IF they similarly up-rate the starter motors, which I bet they don't.

 

[Rocketman]

...which is fair enough, IF they similarly up-rate the starter motors, which I bet they don't.

Well no doubt they have run cycles to give probably in the region ten years of typical use/100K+. The R&D on cars is insane and new models literally are in years in the making.

I've just done some major design mods to the roof dust seals production mould tool that I designed last summer and was manufactured at the same time. The 'premium SUV' is set to hit the market in 2016 some time. No doubt it will be modified again before then to make my life hell after they do more tests.