L-ion batteries - C&MC mag Oct 18

[curdle]

Your suggestion then, (sorry reading different posts in the thread) is that efoy is missold and does not do what it says on the tin?

[aandncaravan]

'Mis-sold' doesn't cover half of it!!!

 

Does it do what it says on the tin? Depends on which 'Tin' you read.

 

If you read the manual although it says Methanol is 'dangerous', it doesn't really explain that Methanol is one of the most toxic substances going. Just 10ml will make you Blind, a tiny 15ml will cause Death.

 

Anyone with an EFOY should read this : https://en.wikipedia.org/wiki/Methanol_toxicity

Note how it states the fumes are as toxic as the liquid?

 

 

Another key issue, where it explains it starts off with very little charge capability, that degrades quite rapidly as you use it, is described in the manual by just 'one line'.

No where else does it explain this huge running cost of £thousands over a 5 year period.

 

I would guess that most EFOY owners that use the unit extensively will not have noticed how much the charge current has degraded from it's original 3.3amps? The owner who contacted us expected his to be down to less than 1.7amps after just 3 years.

 

 

So I am not sure the 'Tin' contains enough information for an assessment?

 

 

But if the 'Tin' said,

"If you want a 3.3a charger that works almost any where (note temperature exceptions and the cost of keeping it from being damaged in low temperature conditions) and you don't mind risking loss of eyesight and even Death every time you recharge the EFOY unit and can cope with rebuild costs of £thousands every few years, then it's the perfect solution".

 

Then yes, it would do what it says on the 'Tin'.

 

 

 

 

[Tracker]

A few years ago a former contibutor on here who also used to be involved with MMM had an 'Efoy' system on trial from the UK suppliers as part of an MMM assessment of its capabilities.

 

I don't recall the details but my perception was that he was impressed although it was expensive and he ceased contributing on here before ever giving any real feedback and as non reader of MM I don't know what their conclusion was.

 

I won't quote his name but other members might also remember the topic?

 

My own natural cynicism at the time thought that anything that appears to be too good to be true very often is just that!

[Derek Uzzell]

You are referring to Clive Mott-Gotobed who Is still a regular contributor to MMM magazine, and it’s easy enough to find his Efoy-related forum comments by using the Search facility (author=Clive).

 

There’s also a lot of fuel-cell stuff on Clive’s own website

 

http://www.motts.org/FUEL%20CELL%20COMPILATION.pdf

[aandncaravan]

Derek, thank you, that is useful as the original 2004 document does highlight that the units power degrades with use, it states,

"After this the units output is likely to drop slowly to around 70% of its original capacity over several months".

However, when the same document talks about 'Costs' no mention is made of the need to regularly pay for the unit to be rebuilt to bring it back to 100%, yet this is surely a significant running cost.

In Steve's case, documented above, his is down to nearly 50% output in less than 3 years.

 

No mention of this 'feature' in the later documents on Clives website.

 

 

Curdle, so maybe we can't answer your question, "Does it do what it says on the tin", but maybe we can do a summary of how we see an EFOY.

 

1. It costs £2,000 to buy.

 

2. Has running costs of near £1,200 every 3 years + Methanol cost.

 

3. Has a very poor battery charger that is likely to cause long term battery degradation.

 

4. Is damaged by sub zero temperatures so needs special protection during cold Autumn, Winter and Spring months.

 

5. Gives a staggeringly poor (for the cost) 3.3amps when new and half this when over 3 years old.

 

6. It uses one of the most Toxic substances going, something rarely noted by the 'reviews'. So toxic, you don't need to drink it as it is absorbed through the skin on contact.

Just mopping up a 'spill' of fluid can be life threatening. As can the fumes.

 

 

 

A Honda EU10i generator seems to me to be a much cheaper, more powerful and flexible solution. Why anyone would prefer to store 5 litres of Methanol in their motorhome locker than a can of Petrol or container of Gas is beyond me.

 

 

.

 

 

[curdle]

Thanks for the detailed and thoughtful replies. On cost to purchase, the cheapest I have seen is actually 2400.00 plus for the smallest unit, so it appears to have become steadily more expensive. I was attracted to the low weight of the unit as well as the ability to charge without annoying any neighbours and from a security point of view, travelling in less developed countries, not having anything external that can be stolen. With a roof rack and aircon unit as well as a largely redundant satellite dish and multiple skylights, I fear solar panels are not optimal with little space and shadows cast by the kit taking up roof space.

[curdle]

"3. Has a very poor battery charger that is likely to cause long term battery degradation."

 

Can you expand somewhat on this detail? I have seen some of your other posts (efoy unrelated) where you talk about charger efficiency.

 

[aandncaravan]

curdle - 2018-10-24 1:24 PM

 

"3. Has a very poor battery charger that is likely to cause long term battery degradation."

 

Can you expand somewhat on this detail? I have seen some of your other posts (efoy unrelated) where you talk about charger efficiency.

 

 

 

The company setup the battery charging defaults on which to start charging the battery as a really low and damaging 12.3v.

At this voltage a quality battery is very heavily discharged and already into the damage zone.

See the chart below from Yuasa which shows a 12.3v battery is around 70% discharged and well below the majority of advice to discharge no more than 50% for the best compromise between life and usability.

 

Also, any battery that stays in a partially discharged state for any length of time will suffer life shortening sulphation damage

So clearly letting a battery discharge so low shows a lack of understanding of them by the EFOY manufacturer which is likely to run through the entire charger design and operation.

 

For example, a quality battery charger that had had been running for a short period of time at 14.4v then drops to 13.8v for several hours to complete the charging.

The best will then drop to 13.2v to maintain the battery in a charged state without overcharging it.

Reaching 14.4v is not an indication the battery is fully charged.

 

At the same point that most chargers drop to 13.8v to finish the charging, the EFOY doesn't, it turns 'straight off' to save fuel leaving the battery only partially charged, possibly only 80%.

 

 

That means the battery will not only suffer damage if left in this state, but only deliver a 'real' 30% of it's power.

 

We have not looked inside an EFOY but it appears to be a basic 'Shunt style' low tech, low efficiency, charger unit.

..

Battery charging is an art and done well by those companies that manufacture both chargers and Batteries, like Victron.

Many of the so called 'reputable' battery charger manufacturers get it very wrong, just have a look at the Sargent 151 which is one of their newer products.

 

 

Just because a manufacturer does 'Fuel Cells' it doesn't mean they understand either batteries or battery charging.

 

I would expect that about 40% of the Fuel Cells 3.3 amps output will fail to make it into the battery to be available to 'withdrawn' at a later date.

Obviously as the EFOY is used, and slowly 'dies', the max generated power reduces so you could be looking at just 60% of those 1.7amps, a miserable 1.02amps MAXIMUM charge rate.

 

 

 

Clive Motts 'technical assessment' and review of the EFOy was really poor as the amount of power actually generated by the fuel cell or drawn from the batteries was not recorded.

We don't even know what the battery SOC State Of Charge, was at the end of the test to indicate whether it was the battery supplying all the power he used or the EFOY.

 

Two decent batteries would have handled the 'load' in his 'test' with just the minimal of charging. They would have been heavily discharged, but because the SOC isn't declared we can't tell,

Forr all we know the EFOY could have been putting out almost zero charge to achieve the same end result.

 

[teccer1234]

aandncaravan

 

as you appear to be the expert on most things can you answer this for me

I'v got 3 + 55 w SP on my roof going to a tracer MPPT controller going to 3 exide sealed 100A batteries.

 

for 6 months in the winter they are used/charged daily while we're living in the van but in the summer back here the batteries are not used but the SP are still connected, would it be better if I removed the 6m wires from the SP at the input to the controller to stop the batteries being topped up until a few weeks before we shoot off again?

[spirou]

In short, yes. As long as you make sure the wires don't ever touch :-D It would be easier if you had a switch/fuse to do the same job.

[curdle]

Alan, I followed your lead on battery cycles, especially mention of Victron. Looking at the specs and your detailed extrapolations, these Victron Gels seem to be a completely awesome battery, well worth any penny spent? Any caveats?

[teccer1234]

good thinking on a switch, only needed on the live/red wire?

 

[aandncaravan]

curdle - 2018-10-25 1:43 PM

 

Alan, I followed your lead on battery cycles, especially mention of Victron. Looking at the specs and your detailed extrapolations, these Victron Gels seem to be a completely awesome battery, well worth any penny spent? Any caveats?

 

 

Tteccer1234, thanks for the compliment, I wish I did know every thing. On our Solar webpages we suggest fitting a fuse in the Solar panel feed to the regulator : http://www.aandncaravanservices.co.uk/solar-power.php

 

 

 

Curdle, Yes the Victon batteries are outstanding for a Gel in terms of Lifetime/cycles and for about £300 they are not bad value considering the life time..

 

However, bear in mind, that like all Gel batteries, they have limitations.

They take twice as long to charge as the best batteries and do not like high current draw or operating in higher temperatures.

 

If you holiday in Norway they will do you proud, if you holiday in the South of Portugal, the life can be reduced down to just a third of their usual life.

See Victrons own temperature versus life graphs further down this web page : http://www.aandncaravanservices.co.uk/agm-batteries.php

 

 

I would have thought that in your particular case that battery efficiency would be top of your priority list, rather than lifetime? If you are looking at low power battery chargers, then a battery that makes the most of every single milliamp it receives, like the Varta LFD90, would be a better proposition than a slow charging Gel battery.

 

As we say on the web pages, with the higher demand on the electrical system of todays motorhomes, we don't think Gel's are the best option.

 

 

 

 

 

 

 

 

 

[Billggski]

Haven't visited this site for a while, but interested in the vilification of methanol in EFOY fuel cells.

I've no interest in promoting it, and yes, there are dire warnings over its use (although less than on toilet blue liquid) but it's a very common product, petrol can have 3% methanol, and we actually breathe minute quantities out when healthy.

 

"Methanol is a traditional denaturant for ethanol, the product being known as "denatured alcohol" or "methylated spirit". This was commonly used during the Prohibition to discourage consumption of bootlegged liquor, and ended up causing several deaths.[41]

 

Methanol is used as a solvent and as an antifreeze in pipelines and windshield washer fluid. Methanol was used as an automobile coolant antifreeze in the early 1900s.[42]

 

In some wastewater treatment plants, a small amount of methanol is added to wastewater to provide a carbon food source for the denitrifying bacteria, which convert nitrates to nitrogen gas and reduce the nitrification of sensitive aquifers.

 

Methanol is used as a destaining agent in polyacrylamide gel electrophoresis.

 

Direct-methanol fuel cells are unique in their low temperature, atmospheric pressure operation, allowing them to be miniaturized to an unprecedented degree.[43][44] This, combined with the relatively easy and safe storage and handling of methanol, may open the possibility of fuel cell-powered consumer electronics, such as laptop computers and mobile phones.[45]

 

Methanol is also a widely used fuel in camping and boating stoves. Methanol burns well in an unpressurized burner, so alcohol stoves are often very simple, sometimes little more than a cup to hold fuel. This lack of complexity makes them a favorite of hikers who spend extended time in the wilderness. Similarly, the alcohol can be gelled to reduce risk of leaking or spilling, as with the brand "Sterno"."

[davidmac]

Hi back in the 70s and 80s I raced a hydroplane and methanol was the fuel we used. I used to buy 205lt drum and keep it my garage. Everyone syphoned methanol from one container to another and you sometimes got a taste of it in your mouth. Lots of spitting and swearing would follow but no ill effects. The biggest problem could be that methanol burns with a clear flame and on occasions the engine would backfire through the carburetors , catch fire and you wouldn't know until something else started smoking or you got your hand burnt. Methanol is not nice stuff but like many other things, if you take care you will be alright.

Regards David

[Derek Uzzell]

There’s a lengthy Wikipedia “methanol” entry that includes advice on toxicity

 

https://en.m.wikipedia.org/wiki/Methanol_fuel

 

[spirou]

Better the devil you know... ;-)

 

The real problem with efoy seems to be the weak charger and short useful lifespan, certainly not the methanol.

[Billggski]

Yes EFOY is an expensive way to get a small 12v charge, useful on racing yachts where space and weight are at a premium.

 

In the last century, when health and safety was having a hard hat somewhere in your van, the BMW powered Chevrons we were racing found they couldn't match the new FVC Ford powered rivals. So we increased the compression ratio by skimming the head and adding methanol to the standard leaded pump petrol (we were supposed to use) to raise the octane level.

We bought it from a standard fuel pump at the local aerodrome, into 5 gallon jerry cans. Splashing into the fuel tanks without a thought.

 

[aandncaravan]

Billggski - 2018-10-27 2:51 PM

 

I've no interest in promoting it, and yes, there are dire warnings over its use (although less than on toilet blue liquid) but it's a very common product, petrol can have 3% methanol, and we actually breathe minute quantities out when healthy.

 

"Methanol is a traditional denaturant for ethanol, the product being known as "denatured alcohol" or "methylated spirit". This was commonly used during the Prohibition to discourage consumption of bootlegged liquor, and ended up causing several deaths.[41]

 

Methanol is used as a solvent and as an antifreeze in pipelines and windshield washer fluid. Methanol was used as an automobile coolant antifreeze in the early 1900s.[42]

 

In some wastewater treatment plants, a small amount of methanol is added to wastewater to provide a carbon food source for the denitrifying bacteria, which convert nitrates to nitrogen gas and reduce the nitrification of sensitive aquifers.

 

Methanol is used as a destaining agent in polyacrylamide gel electrophoresis.

 

 

Methanol is also a widely used fuel in camping and boating stoves. Methanol burns well in an unpressurized burner, so alcohol stoves are often very simple, sometimes little more than a cup to hold fuel. This lack of complexity makes them a favorite of hikers who spend extended time in the wilderness. Similarly, the alcohol can be gelled to reduce risk of leaking or spilling, as with the brand "Sterno"."

 

 

All of the uses you speak of are with Methanol in very low concentrations, like the 3% in Petrol, low concentrations in Antifreeze, etc.

 

Like you say "In some wastewater treatment plants, a SMALL amount of methanol is added to wastewater...............".

Ethanol makes Methanol safer, hence there being a 'mix' of it in Antifreeze, screen wash.

 

EFOY on the other hand is 100% pure Methanol and very different proposition.

 

 

 

The warnings I relayed on it's on it's toxicity came from Wiki. Few products are so deadly they can cause Blindness/Death by absorption through the skin, and I bet that is something most EFOY users don't realise.

.

 

As for the Methanol camping stoves, those I used were "alcohol", based Isopropyl Alcohol.or Ethanol and Meths mixes, like this one : https://www.amazon.co.uk/Solo-Stove-Alcohol-Burner-Backpacking/dp/B008VZ91WO

Never came across one that was 100% Methanol.

 

 

I also have no vested interest on EFOY either positive or negative.

 

I have only been given 6 months to live and that was at the end of August, so any 'ulterior' motive I might have isn't going to gain me very much for very long.

I clearly don't have any vested interest in selling them so more independent than most.

 

Just telling like I see it, but putting in the negatives that others forget to include.

 

 

.

[aandncaravan]

arthur49 - 2018-10-05 9:36 PM

 

Thank you for input Allan. I restricted my input to the simple weight and cost of lead-acid, so obviously flawed ..........

 

 

Arthur, Someone has emailed me an article on Lithiums that states that the new present thinking is that, for maximum life, Lithiums are best not kept charged above 80% and not discharged below 20% DOD which leaves a 60% range of charge/discharge. All backed up from several sources and seemingly sound arguments.

 

If that is the case then may I re-compare Lithium to the best of Wet Acid technology for claims that Lithium are '3 times lighter', or whatever the absurdity is.

 

 

The Victron Energy Super cycle Flooded/wet acid battery is guaranteed to discharge to 100% DOD (that is zero capacity left) and still give long cycle life.

The Victron website states :-

"Tests have shown that the Super Cycle battery does withstand at least 300 x 100% DoD cycles".

 

 

So comparing two batteries, the 25kg Victron with it's 100Ah 'cycle depth', versus a 13.3kg NDS 100AH Lithium Iron that delivers a 'cycle depth' of 60Ah seems to me that they are Ah per kg pretty close.

Lithium 60Ah per 13.3kg = 4.8 Ah/kg

Victron 100Ah per 25kg = 4.0 Ah/kg.

 

However, if you add on the extra 3 kg weight of the higher powered Alternator required to safely/reliably recharge a Lithium battery, the fatter 35mm/0.7kg per metre cable (about 6 metres of both Red and Black required at 8.4kg), uprated 100amp battery charger, connectors, etc you can see the Lithium installation comes out about 13 kg heavier overall than the Victron Energy Super life 12-110 Lead Wet Acid battery.

 

Comparison Including 'installation' weight :-

Lithium 60Ah per 26.3kg = 2.3 Ah/kg

Victron 100Ah per 25kg = 4.0 Ah/kg.

 

Really does present a different picture when you lay it out like that doesn't it? - Must be something wrong with my maths, because that suggests Lithiums installed in a motorhome are almost twice as heavy as the best flooded batteries!!!

 

 

I think that suggests, that when all the facts are taken into account, there hasn't always been honesty in the marketing world.

But when the motorhome Lithium profit margins are so high, then greed might be expected to make an appearance now and again?

 

 

Anyway, Arthur, I think that entitles you to say, "I told you so"?

 

 

I have heavily revised the Lithium battery pages to suit : http://www.aandncaravanservices.co.uk/lithium-batteries.php

 

 

 

 

[arthur49]

aandncaravan - 2019-01-21 8:15 PM

 

Anyway, Arthur, I think that entitles you to say, "I told you so"?

 

 

 

Thank you again Allan for your work and input on this and all things electric/electronic on MHs.

 

I used your "I told you so" to my wife .... maybe she said but she still insists I load the dishwasher incorrectly :-D :-D :-D

[spirou]

Allan, while I agree lithium is overrated and overpriced, your comparison isn't really fair. You're comparing max capacity to long life capacity. Victron can obviously do 300 cycles at 100% DOD but any lithium battery can probably do that and more at 100% DOD. Both give a lot more cycles at lower DOD.

 

A better comparison would be how many cycles each can do at 60% capacity. One cycled between 80 & 20, the other between 100 & 40. Then you can do €/cycle or whatever you want.

[aandncaravan]

spirou - 2019-01-22 4:19 AM

 

Allan, while I agree lithium is overrated and overpriced, your comparison isn't really fair. You're comparing max capacity to long life capacity. Victron can obviously do 300 cycles at 100% DOD but any lithium battery can probably do that and more at 100% DOD. Both give a lot more cycles at lower DOD.

 

A better comparison would be how many cycles each can do at 60% capacity. One cycled between 80 & 20, the other between 100 & 40. Then you can do €/cycle or whatever you want.

 

 

Arthur, I also stack the Dishwasher 'wrong', but then I do it deliberately so I don't get asked again. :D

 

 

 

Spirou, one of the problems of doing comparisons is that Lithium manufacturers won't publish what the battery will achieve at 60% DOD.

In fact if you can find me a single companies testing document to ratify the cycle life of their Lithium, I will be amazed.

 

I can't even find a BS EN standard to be used by manufacturers to follow when testing Lithiums. For example, when the battery was charged, was it charged at a life extending 0.5a charge, or a battery buckling 20 amps?

When it was discharged in the cycle test, was it using a current of 10amps or a life extending trickle of 0.5a?

Was it kept in an Ice Cold bath during the testing or was it at 25 degrees C, remember warmth is a killer for Lithium use?

Each manufacturer seems to do their own testing following their own guidelines.

 

 

As for 100% discharges, we don't know any top lithium expert web site that advocates discharges to 100%, because the effect on their life is devastating, hence the new advice not to discharge down to below 80% DOD.

That is why the best new Lithium electronic Battery Management Systems (BMS) shutdown all power draw before 90% is reached.

 

Most lithium packs will suffer catastrophic failure at greater than 95% DOD and most will be unable to deliver even 200 cycles.

 

 

I would be surprised if ANY motorhome lithium battery pack on the market would last survive a 100% DOD discharge without damage.

Note here we talk about motorhome targeted Lithium Iron (LiFePo4), not the Cobalt technology used in the Dreamliner, etc.

 

Have a look at the chart attached below which shows how the 'claims' of "3,000+" cycles at a very shallow 20% DOD are so very different to 100% DOD.

 

At a 50% DOD discharge you can see a massive 2,500 cycle loss between a misleading 20% figure and the 1,000 cycle/50% DOD figure that is something nearly comparable to Lead.

 

By the time you get to 100% DOD it has lost more than 10 TIMES is 20% capacity figure that is often quoted in the motorhome press, 3,000+ down to a meagre 250 cycles.

 

Bear in mind the cycle life graph below isn't to the same BS EN 50342 standards that all lead acid batteries should be tested to.

.

 

 

 

Battery Management systems (BMS) in motorhome Lithium packs :

A BMS is an electronic device, usually inside the battery casing.

This device limits current draw, charging rate, discharge depth, etc.

It is permanently connected to the Lithium battery pack protecting it by monitoring the battery state and drawing power.

 

What do you think will happen if the battery pack is left unattended all winter?

 

It is worth noting that the Water Cooled Tesla Lithiums have so far proved to retain capacity, except in situations where the vehicle has been left unused for a while when the pack has required replacement.

I think there is now something in the Tesla warranty 'exclusions' about idle use.

 

 

 

Check out the chart below and see how it 'might' achieve 3,000+ cycles at 20%DOD, but see how this plummets down to just 1,000 cycles at 50% DOD?

 

 

How many of the motorhome lithium pack batteries have been quoting a comparable figure to a Lead batteries 50%?

Isn't that shocking to see it's only a 'few more' cycles than the legendary old Exide G80's 750 cycles?

 

 

Sorry, but I think much of the Lithium marketing is still 'Science Fiction' and really pleased the DBEIS have brought Lithiums into the current battery 'evaluation' campaign.

 

 

 

[spirou]

Don't have time to research much, just comparing Victron spec sheets

 

LiFePO

https://www.victronenergy.com/upload/documents/Datasheet-12,8-&-25,6-Volt-lithium-iron-phosphate-batteries-Smart-EN.pdf

 

CYCLE LIFE (capacity = 80% of nominal)

80% DoD 2500 cycles

70% DoD 3000 cycles

50% DoD 5000 cycles

 

So taking a standard 100Ah battery pack it is automatically downrated to 80Ah. If we still want 60Ah out of it, that goes right between the 2500 & 3000 figures above.

 

Their new lead carbon battery:

= 1000 cycles at 60% DOD

= 500 cycles at 100% DOD

https://www.victronenergy.com/upload/documents/Datasheet-Lead-carbon-battery-EN.pdf

 

AGM supercycle

= 300 cycles @ 100% DoD

= 700 cycles @ 60% DoD

https://www.victronenergy.com/upload/documents/Datasheet-AGM-Super-Cycle-battery-EN.pdf

 

Prices are also available to anyone on their website. OK, they don't specify the lithium testing procedure, but if we believe them on lead-acid technology, perhaps they can be trusted on lithium?

[Paul-]

Morningstar are doing interesting research and advice on Li-ion batteries at the moment, I can't give the full email but will give a link https://www.morningstarcorp.com/energy-storage-partner-program/