jrkitching said:

On S/S cars, voltage stability would seem to be much more important - we'll be replacing these batteries long before they become too weak to turn over the engine on cold mornings.

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Charge acceptance is the big thing with S&S - even a bog standard alternator can supply a lot more current than a lead/acid battery can cope with on regular basis, but when you start getting regeneration in the equation, it's not much wonder a battery can't cope. So after a number of months, the battery simply can't recover to a decent state of charge after a number of starts.

This is why alternative chemistry is the only way forward in the long term!

bgunn said:

Charge acceptance is the big thing with S&S - even a bog standard alternator can supply a lot more current than a lead/acid battery can cope with on regular basis, but when you start getting regeneration in the equation, it's not much wonder a battery can't cope. So after a number of months, the battery simply can't recover to a decent state of charge after a number of starts.

This is why alternative chemistry is the only way forward in the long term!

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Cost will likely be the biggest obstacle. That EL600, replaced every 3 yrs, works out at £28.33 pa.

I can live with that. Replacing the alternative chemistry batteries in my mobile phone costs me more.

jrkitching said:

Cost will likely be the biggest obstacle. That EL600, replaced every 3 yrs, works out at £28.33 pa.

I can live with that. Replacing the alternative technology batteries in my mobile phone costs me more than that.

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Oh, definitely, and as we can't change the programming of our S&S, it'll only ever work when the car isn't moving, so the demands aren't that high.

The difficulty will come when legislation forces the tech again, when cars are expected to stop when coasting, and the whole 'micro-hybrid' idea starts getting pushed that bit further, but the costs still have to stay low.

bgunn said:

Oh, definitely, and as we can't change the programming of our S&S, it'll only ever work when the car isn't moving, so the demands aren't that high.

The difficulty will come when legislation forces the tech again, when cars are expected to stop when coasting, and the whole 'micro-hybrid' idea starts getting pushed that bit further, but the costs still have to stay low.

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The big problem with any battery based solution is degradation over time. Maintaining the initial efficiency over the lifetime of the vehicle will be the challenge.

I'd favour some form of mechanical system using flywheel energy storage for the citycar of the future.

Lead/acid is really rather crap though and the only thing going for it is that the infrastructure to produce it is all there. You're lucky to get 200 cycles out of one if the Depth of Discharge is more than 50-60% (which is not out of the realms of possibility with a modern car using S&S and lots of other toys).

LiFePO4 will do 2-7000 cycles (!) with 100% DOD. So with some good charging circuitry and voltage stabilisation to disable unnecessary kit when the voltage drops, cars will suddenly behave a *lot* better. And the cell size and weight is tiny compared to the huge brick you need in a Pb/H2SO4 battery. Granted, there are obstacles to overcome, but the technology is there.

Couple that with super capacitor type tech, which allows really good rapid energy storage/release which will take the 'heat' off a battery for brake energy regeneration, and the two technologies could compliment each other well.

jrkitching said:

Euro is expensive, full stop. Much cheaper here

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They are cheap for somethings (just got to shop about)

I got my battery from the same site you link the only issue i had was it took a week to arrive (when i chased it apparently it had been returned due to the shipping label falling off) any ways it turned up next day after the phone call...

bgunn said:

EL600 is the battery specced for the car, FIAT lists it as £145.96 on ePER at December's price.

FIAT lists it as a 60Ah, 450CCA (EN) battery, although I notice that the spec of the battery given on that link is 540CCA (EN)- so it's obviously an improvement on the initial spec. Mind you, CCA figures are like NEDC economy figures - ****e and pointless

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suppose that price tallies with the £220 i was quoted by the time you stuff VAT on it and half an hours labour.....




Cant understand whats going on with the capacity's it looks like the after market Exide have dropped 3 Amp hour from it and 10a of its CCA

http://www.justcarbatteries.co.uk/i...o-hybrid-ecm/exide-el600-096-ecm-battery.html

jrkitching said:

On S/S cars, voltage stability would seem to be much more important - we'll be replacing these batteries long before they become too weak to turn over the engine on cold mornings.

On a positive note, if we're replacing batteries early to avoid annoying premature S/S restarts, we might just be spared the spurious EPAS warnings which seem to proliferate on the Panda forum.

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But then bargain on the offset of the environmental savings of co2 and less fuel used by your car stopping... by the battery manufacturer and pollution involved in transporting its components and the finished item probably half way round the world and getting rid of it at the end of its service life :shakehead: (then again the scrappies like them for the lead) :devil:

bgunn said:

Charge acceptance is the big thing with S&S - even a bog standard alternator can supply a lot more current than a lead/acid battery can cope with on regular basis, but when you start getting regeneration in the equation, it's not much wonder a battery can't cope. So after a number of months, the battery simply can't recover to a decent state of charge after a number of starts.

This is why alternative chemistry is the only way forward in the long term!

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Thats the reason for the ECM base of the batteries not done much homework on this but i believe it enables the battery to take more charge / discharge abuse than a standard car battery







As i mentioned earlier i dont think you will get any bigger battery in than the el600 as its a little tight in the engine bay of the 500

Andy Monty said:

Cant understand whats going on with the capacity's it looks like the after market Exide have dropped 3 Amp hour from it and 10a of its CCA

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Gained 90A on Cold Crank?

Andy Monty said:

But then bargain on the offset of the environmental savings of co2 and less fuel used by your car stopping... by the battery manufacturer and pollution involved in transporting its components and the finished item probably half way round the world and getting rid of it at the end of its service life :shakehead: (then again the scrappies like them for the lead) :devil:

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It is indeed a balance. Purely from a noise point of view, it does seem rather antiquated to have a car idling away whilst doing nothing. If the tech is done properly, it can deliver benefits.

Andy Monty said:

Thats the reason for the ECM base of the batteries not done much homework on this but i believe it enables the battery to take more charge / discharge abuse than a standard car battery

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Yup - a standard flooded cell will fall apart very quickly! Absorbed Glass Mat is even better for charge acceptance and cycle life; but more expensive and not as tolerant of heat.

Andy Monty said:

As i mentioned earlier i dont think you will get any bigger battery in than the el600 as its a little tight in the engine bay of the 500

View attachment 112604

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Yes, I was going to mention this in the other thread I was talking about batteries on, I checked my engine bay last weekend and there is no space at all for a bigger battery in the engine bay. That said, if you were that way inclined, you could use an AGM battery (which doesn't really like the heat of an engine bay), and stick it in the spare wheel well (with some wiring modifications, of course).

bgunn said:

Gained 90A on Cold Crank?

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My mistake was looking at a different battery entirely

bgunn said:

The difficulty will come when legislation forces the tech again, when cars are expected to stop when coasting...

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No modern car uses any fuel while coasting in gear.

bgunn said:

LiFePO4 will do 2-7000 cycles (!) with 100% DOD. So with some good charging circuitry and voltage stabilisation to disable unnecessary kit when the voltage drops, cars will suddenly behave a *lot* better.

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The whole point is LI battery voltage doesn't drop under load like PB batteries do. If you went with a battery of the same physical size, you would have the equivalent of something like 150AH and 1000CCA. That kind of reserve would never have any problem with voltage drop, and could probably sit unused for a number of years and still start right up. Also, drop in replacement batteries with over/under voltage protection do exist.

UFI said:

No modern car uses any fuel while coasting in gear.

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Is that your final answer?

The TA and any other Multiair engines don't. I admittedly don't know about diesels since they are the work of Satan. It's also possible some TATA or something don't bother with injector off coast, but then it's not exactly a 'modern' car

UFI said:

No modern car uses any fuel while coasting in gear.

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That's a rather sweeping absolute generalisation...

306maxi said:

Is that your final answer?

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Now you're teasing him...

The vast majority of modern petrol engine ecus will cut off all fuel when there is no input from the accelerator, but only if the engine rpm is above a threshold. Once rpm drops below that threshold, the ecu will start to feed fuel to keep the engine turning smoothly - on my 500, with a warm engine, that begins at about 1500rpm.

However, even when all fuel is cut off, the frictional losses in the engine do not go away. What I think bgunn is saying, correctly, is that to move to the next stage of economy, we'll need to completely disconnect the engine from the drivetrain when coasting. For this to save any meaningful fuel, though, the car will also need some kind of regenerative braking, otherwise you'll lose most of the energy you saved coasting when you put the brakes on.

jrkitching said:

Once rpm drops below that threshold, the ecu will start to feed fuel to keep the engine turning smoothly - on my 500, with a warm engine, that begins at about 1500rpm.

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The TA keeps it's injectors off until very close to idle (It's such a close run thing that it's of course difficult to tell exactly without data logging). I was very pleasantly surprised by this as I was expecting them to kick in at around at 1500rpm mark as is fairly typical. It's pretty magic coasting in gear, using no fuel until you have to put it in neutral, and the only burning a few drops until the ECU reports 0km/h and the S/S kicks in On the other hand I nearly bought the Audi A1 as it has regen braking already, coupled with S/S which is IMO the only way to do it. I would not have spec'd S/S on the TA if it were possible, I'd rather have the weight savings.

UFI said:

The TA keeps it's injectors off until very close to idle (It's such a close run thing that it's of course difficult to tell exactly without data logging).

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Without decent telemetry, it's very hard to know for sure - it could also be that the reintroduction of fuel with decreasing rpm is progressive & well controlled.

jrkitching said:

However, even when all fuel is cut off, the frictional losses in the engine do not go away. What I think bgunn is saying, correctly, is that to move to the next stage of economy, we'll need to completely disconnect the engine from the drivetrain when coasting. For this to save any meaningful fuel, though, the car will also need some kind of regenerative braking, otherwise you'll lose most of the energy you saved coasting when you put the brakes on.

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Pretty much. The start & stop system is regarded as a 'micro hybrid' system, as the engine management controls the alternator to create regenerative braking effect by increasing the charging rate when coasting or braking whilst in gear. As you say, frictional losses in the engine do reduce this effect, but a multiair engine will at least have a far lower level of pumping loss than a 'conventional' engine.

Like you say, a full hybrid will have the ISG sitting between the engine and 'box, giving the benefits that it does. There were rumours that FIAT were going to play on the benefits of the short twin cylinder engine to make a baby hybrid.

ahmett said:

what exact type of battery do I need for my fiat 500 1.4? It is non s/s.

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Open the bonnet and read what it says on the old one?

Mondaugen said:

Open the bonnet and read what it says on the old one?

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Lots of folks (me included) do that as a way of working out what replacement parts to buy.

The inherent difficulty with this methodology is it assumes what is there now is the correct part for the car.

Unfortunately, this isn't always the case - someone (even the factory) may have put the wrong part in last time around, or the part may have been superseded by a newer or better version.

It's always best to get independent confirmation before ordering or fitting parts.

If you have 45 mins to spare, and want an unforgettable lesson in what can go wrong if you just use what's there as a pattern, watch this video:

jrkitching said:

Without decent telemetry, it's very hard to know for sure - it could also be that the reintroduction of fuel with decreasing rpm is progressive & well controlled.

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The OBD reports 0.0l/hr until the 'shift down' light comes on. Like I say, it's very hard to read both RPM and l/hr at the same time (and there's always some latency of course), maybe I need to video a few runs