Lithium Ion Battery

[Nifty]

Has anyone fitted a lithium ion battery to their 7 ?

I'm very interested in doing this and wonder what anyone's views were. I have heard they cannot be jump started as a normal battery can .. but then they should be less suscepptible to battery drain so providing they are being charged correctly when running this should be one of the benefits, as well as cranking current and weight.

Would like to put one in the Esprit too as this has a very heavy, hard to access lead acid lump in the rear corner that constantly drains down and requires jumping.

[Jonathan Kay]

Yes, with some experience of particular models: 1, 2, 3. 

I'm surprised this hasn't been more widely discussed or adopted.

Jonathan

[andy couchman]

A mate has one in his Boxster Sptyder. Porsche recommend you don't use it in winter but otherwise it looks to be fairly 'normal'.

Mega expensive and is it much of an advantage of say an Odyssey?

Andy

[OliverSedlacek]

I think the lead acid battery is dead! The weight saving per pound spent makes a Lithium battery one of the best upgrades you can buy.

[OliverSedlacek]

This is driving me nuts! I've started researching what's available and it's proving really hard to get data from the manufacturer's websites. Can anyone provide any model numbers and links to data? Any makes other than Skyrich?

[keybaud]

I use LiPOs for radio control models and regularly have to replace them. They have fantastic discharge rates and the rate at which they can be charged is getting better, but they are much more delicate than a lead acid and can easily be damaged beyond repair. Even storing them at the incorrect charge state can damage them and discharging them too far kills them stone dead. If weight is a primary consideration, the LiPO is the way forward, but if reliability is more important, then I'd stick with lead acid.

[Mankee]

I don't know if I updated my posts, but as well as the alternator overcharging my lithium battery at 15.5+v, I've also TOTALLY flattened it accidentally. What a prat. But I hooked up the CTEK, crossed my fingers and it is spot on again, now that there is nothing draining it down. Maybe they aren't as fragile as people think they are?

If anyone in the Ipswich-ish area wants to come try it out and be amazed at how light it is, give us a shout.

[ric355]

I bought one a couple of weeks ago and am currently in the process of installing it. Physically it's done and I've started the car with it but I am currently installing a battery master switch so everything is disconnected presently.

With regard to the initial comments about battery drain, for clarity they are not less susceptible to drain except when the load is completely removed, in which case they'll hold a charge for longer than the lead acid equivalent under the same conditions. Perhaps this is what was meant above anyway. This is why I'm fitting a master switch, since the old 5AS will drain an odyssey in about 3 weeks so it'll do the same to the lithium. Depending on what constant drain there is, it might not be suitable for the Esprit unless it is driven regularly or you fit a master switch.

Lithium batteries can be charged with some regular chargers but not all. It seems the ones that do desulphating and other clever things are to be avoided, but a constant current type charger with a voltage sense is usable, because that's basically the same as an alternator output. I haven't tried my own charger as I don't know exactly what type it is. Safest option is a proper lithium charger (and a battery maintainer like an optimate is not suitable unless it's a proper lithium one). They charge very quickly by comparison to a lead acid battery too, based on what I've read. The reason I mention this is if you feel you need a charger it adds a significant percentage to the purchase price. I haven't bothered (yet!).

With regard to jump starting, I didn't see any information on this being a problem and unfortunately you can't easily google for suitable info because there are so many portable lithium jump starters out there.

I bought mine from Anti Gravity Batteries http://www.antigravitybatteries-uk.co.uk/small-case-type-batteries.html

I bought the 12 cell small case type. You can hold it in one hand it's so small. First press of the starter button and the engine turned over very quickly. I have very few electrical devices on the car and it's an 1800 K series engine. Not a particularly high compression at 160bhp. Blurb on the website says it is good for race cars up to 1800cc, but the box says 1500cc so I've yet to find out whether it has problems. Definitely delivers a good kick for starting though (380cca) and I can't really see it having any trouble as there's little draw on it other than engine and - very rarely - lights.

There's a technique to starting a car with a lithium if it's very cold. Cold lithium batteries have high internal resistance but the good news is if you draw current from them they heat up quickly and the internal resistance drops, thus it's the opposite to a lead acid battery in the cold - the more times you try it the better kick you get from it. Nice video on youtube about it where they start a motorbike in -10c. Guy blabbers on a bit though (like me here?!).

Other batteries I came across - Super B - more expensive and seem no different. Sold by Demon Tweeks amongst others. Racing Batteries was another I think - probably mentioned in one of the threads already linked in one of the posts above. Their range seems to have changed a bit though.

I did find one other but can't remember what it was called. I only remember it was green. In the end I bought the one I felt most confident with which was really based on the information on their website and the competitive price. Still expensive compared to an Odyssey, but I didn't feel like I was being ripped off.

[BBL]

From the 7 owners I have talked to with LiFePO4 batteries, the trick in cold weather is to turn on the headlights for 10-12 seconds first to warm up the battery, then turn them off and start the car.

Or so I have been told - this is not my own first-hand experience, as my PC625 is still going strong.

[Jonathan Kay]

Is there still a question for car/bike use about it being desirable to have a specialised control system?

Thanks

Jonathan

[Roger Ford]

 

This is why I'm fitting a master switch, since the old 5AS will drain an odyssey in about 3 weeks so it'll do the same to the lithium

The capacity of a lithium battery is usually very much lower than a lead acid battery - typically only 4-6 Ah against 18-25 for a lead acid in a Caterham.  So you'll actually drain it much faster if you have a parasitic load. And, as said, if you discharge it too far you have to throw it away.

I can't see any reason why you shouldn't jump start them. After all, you're only connecting the outlet of another car's alternator to them, and they cope fine with the voltage from your alternator.  Perhaps it refers to using specialist fast-charge / jumpstart power packs, which might use a higher than normal voltage.

A lithium battery with the same capacity as a lead acid battery would probably be larger, and not very much lighter. Lead acid batteries might be 150 year old technology, but they still compare well against the most modern technologies in terms of energy density (in space, if not in weight) and better than most in terms of durability.

[ric355]

The capacity of a lithium battery is usually very much lower than a lead acid battery - typically only 4-6 Ah against 18-25 for a lead acid in a Caterham.  So you'll actually drain it much faster if you have a parasitic load. And, as said, if you discharge it too far you have to throw it away.

I wasn't trying to suggest it would last as long as a Lead Acid, only that the drain has to be removed completely otherwise there's no point in making the swap. Fitting the master switch is obviously intended to avoid the deep discharge possibility.

Agree re jump starting but they don't like alternator voltages more than about 14.6 so clearly anything higher may cause damage. I don't know what those big jumpstart packs that garages use do but you can imagine it's more than just a parallel battery.

The main reason I switched is that I killed my odyssey by leaving a jump starter connected. It had gone flat due to the 5AS, so I tried to boost it with a mains powered 80A jump starter. I intended to leave it for a few minutes before trying to fire it up, but got distracted and went back 2 hours later to find a swollen rather warm battery with a strange smell coming from it.

My car is only a track car by the way, so I don't need to worry about practicality so much. I think I'd still have a Banner if I used it for lots of touring etc.

[Jonathan Kay]

I don't know what those big jumpstart packs that garages use do but you can imagine it's more than just a parallel battery.

I think they're just high-capacity batteries in jumping mode but they may include sensing circuits. So no difference from anything domestic apart from capacity.  I don't think they will lift the voltage above alternator levels because that might wreck any car electronics as well as cooking the battery. (They often include 24V output but that's not really a potential difference.)

Jonathan

[LazerBrain]

very subtle Jonathan :-)

[Roger Ford]

tried to boost it with a mains powered 80A jump starter. I intended to leave it for a few minutes before trying to fire it up, but got distracted and went back 2 hours later to find a swollen rather warm battery with a strange smell coming from it

So that must indicate that it was supplying more than "standard alternator" voltage.  You don't cook a battery by having a steady 14.Xv on it from an alternator, and the current taken by a battery will depend only on the voltage supplied to it (assuming that the supply voltage doesn't droop when you take a high current).

[Jonathan Kay]

Is there some ambiguity between "jump starter" and "charger"?

Jonathan

[ric355]

So that must indicate that it was supplying more than "standard alternator" voltage.  You don't cook a battery by having a steady 14.Xv on it from an alternator, and the current taken by a battery will depend only on the voltage supplied to it (assuming that the supply voltage doesn't droop when you take a high current).

Yes I cooked the battery by leaving something connected that shouldn't have been. My fault and the result was no surprise 

Nothing to do with Lithium batteries any more, but this is the unit:

http://www.halfords.com/motoring-travel/bulbs-wiper-blades-batteries/car-battery-chargers/ring-rcb320-battery-charger

I left it in the 80A boost mode. It can supply 80A for around three seconds to start an engine with a flat battery but I have a feeling it bumps up the output voltage at the same time. I guess there might be a massive capacitor inside it or something.

The battery has some history anyway having been deep discharged multiple times for various reasons and been exposed to a faulty alternator. So I knew it was time to replace anyway, and hence took the Lithium option (getting back on topic!). Appreciate not everyone thinks they're suitable - I'm keeping an open mind and time will tell.

[OliverSedlacek]

Two comments, the full charge voltage of a four cell lithium battery is 16.4V, so 'overcharging' to 15.5V shouldn't harm a lithium battery. Secondly, a lithium battery of the the same Ah capacity of a lead-acid battery will be less than half the weight.

[ric355]

Are you sure about those figures? They look a little high. "Nominal voltage" of LiFePO4 cells is 3.2v and 3.6v fully charged I think. This makes a 4 cell Lithium 12.8v nominal and 14.4v fully charged.

There's a big sticker on the box of my battery saying "Battery Voltage Must Not Exceed 14.6v or Drop Below 11.6v Irriversible (sic) damage may occour (sic)"

[keybaud]

Lithium batteries are also charged by a different method (constant current) to lead acid batteries, so the battery will have to contain circuitry to stop them from being damaged by a lead acid battery charger. I assume that the electronics can't handle the very high currents of a jump start battery, which is much higher than a charger or alternator output, so the issue is the current, not the voltage. The high current may damage the internal circuitry of a lithium battery, whereas the lead in a lead acid battery can take quite a beating, as there are no electronics to be damaged.

The electronics will also be why you can recharge a dead lithium battery, because it wasn't actually dead, it was protected when it reached a minimum voltage, so only pretending to be dead. All this extra gubbins is something else to go wrong, so, as I said earlier, lithium for reduced weight, lead for reduced maintenance.

Other reasons I wouldn't use a lithium battery in a car, is the same reason I won't charge my lithium batteries inside a car:

https://www.youtube.com/watch?v=jjAtBiTSsKY

http://www.rcnews.net/2014/04/25/lipo-battery-fire-spreads-through-shed/

/edit Electric cars are designed to use lithium batteries and the entire charging mechanism is also designed for lithium batteries, whereas I wouldn't put a lithium battery in a car with a charging system for lead acid and chargers at home that are designed for lead acid. There are too many factors that could cause a problem and a burnt out Caterham isn't on my list of things I'd like for Xmas.

I'm still looking for the photo of a burnt out BMW 3 series, where the owner user to rehcrage his radio control batteries with a proper lithium 12V charger. I say 'used to' as the car was damaged beyond repair in the ensuing fire when one of his batteries exploded.

[Roger Ford]

Hard to imagine any electronic circuitry that could handle 200+ amps when starting, so I think you're wrong there. That's also why they can't just cut out when they reach a minimum voltage - the only way to do that would be to have a 200 amp solenoid built in to disconnect the circuitry.

edit: lithium ion have max voltage of 4.2v per cell, LiFePo is 3.6v, probably explaining some of the confusion above. I assume car batteries are LiFePo. The chemistry is a bit safer than LiIon, but can still be rather dangerous if abused.

[Jonathan Kay]

Why does the high current drawn by a starter when jump-starting have to go though the host battery?

Jonathan

[Roger Ford]

It doesn't, you could disconnect the battery before jumping. But then the alternator output wouldn't have anywhere to go which I suspect might damage the alternator, and/or the ECU, which is why I didn't suggest it before.

Edit: it's not the high current that's the issue, that would never go through the battery, it's the (possibly) high voltage from the jump starter which is the problem.

[Jonathan Kay]

Yes, but what voltage do big "garage" jump starters deliver? My guess remains that it's not that high but they have enough internal oomph to supply a big current without dropping the voltage. 

I assume that the electronics can't handle the very high currents of a jump start battery, which is much higher than a charger or alternator output, so the issue is the current, not the voltage. The high current may damage the internal circuitry of a lithium battery, whereas the lead in a lead acid battery can take quite a beating, as there are no electronics to be damaged.

but

... it's not the high current that's the issue, that would never go through the battery, it's the (possibly) high voltage from the jump starter which is the problem.

Does anyone know of advice from the battery manufacturers or recovery organisations on jump-starting?

Jonathan

[The_ASH]

Has anyone fitted one of these :-

http://pages.ebay.com/link/?nav=item.view&alt=web&id=201255226858&globalID=EBAY-GB

Looks quite expensive (and stock is in Italy) but very similar dimensions to the Banner item and only 2kg compared to 8 standard.