EZA 130 Lithium Power-Pack (1 Viewer)

[Windy66]

Totally respect your cleverness
What size pack would supply a 2kw inverter

I'm not sure you can. I know you can tether two EZA's together with a coupling unit. I don't know if you can connect a 2k inverter to the coupling unit.

 

[Wissel]

@Robert Clark

As I'd hazard a guess you'd possibly look at the Victron LifePO4's if you did go down this route, I had a look at the specs.

A 2000w inverter will draw 160A at full power (2000w divided by 12.5v for anyone interested).

The Victrom 90Ah can continuously discharge at 270A
The Victrom 160Ah can continuously discharge at 400A

EDIT - missed Victron's recommended figures, which are 90A and 160A respectively. So a single 160Ah would be fine.

 

[Robert Clark]

@Robert Clark

As I'd hazard a guess you'd possibly look at the Victron LifePO4's if you did go down this route, I had a look at the specs.

A 2000w inverter will draw 160A at full power (2000w divided by 12.5v for anyone interested).

The Victrom 90Ah can continuously discharge at 270A
The Victrom 160Ah can continuously discharge at 400A

The BIG problem with the Victron batteries is that they only come with a 2 year guarantee, whereas the Varta’s come with 4 years

Product confidence wins

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[Ralph-n-Bev]

@Robert Clark Your Victron Multiplus is fine for Lithium but you will also need a BMS (battery management system)
If you are on Euro 5 or 6 you will also need the Victron Buck Boost.

Add the above with connecting leads to a Victron 200Ah LifePo4 ........£3,385.00
Expensive but its a good setup. At least with the Victron Lithiums you can pull some big Amps from them. From memory I think its around 300 Ah.

Something to think about

 

[Wissel]

The BIG problem with the Victron batteries is that they only come with a 2 year guarantee, whereas the Varta’s come with 4 years

Product confidence wins

Agreed. The batteries I'm looking at (300Ah smart LifePO4 setup with Bluetooth etc) come in at around £1600 (from memory - loads of figures in my head today). A 5 year warranty can be added for around £100.

Thing is, I'll be ordering from abroad (Europe), so not sure how good that warranty would be. Think I'm going to take advice I've had from @Gromett and be clinical with how they are charged and min/max voltages (system I'm looking at has fully programmable BMS)

 

[Robert Clark]

@Robert Clark Your Victron Multiplus is fine for Lithium but you will also need a BMS (battery management system)
If you are on Euro 5 or 6 you will also need the Victron Buck Boost.

Add the above with connecting leads to a Victron 200Ah LifePo4 ........£3,385.00
Expensive but its a good setup. At least with the Victron Lithiums you can pull some big Amps from them. From memory I think its around 300 Ah.

Something to think about

Mrs C reckons I’ve spent (invested) enough already.

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[Robert Clark]

Agreed. The batteries I'm looking at (300Ah smart LifePO4 setup with Bluetooth etc) come in at around £1600 (from memory - loads of figures in my head today). A 5 year warranty can be added for around £100.

Thing is, I'll be ordering from abroad (Europe), so not sure how good that warranty would be. Think I'm going to take advice I've had from @Gromett and be clinical with how they are charged and min/max voltages (system I'm looking at has fully programmable BMS)

I’ve come to the conclusion that £ for lb that if you have the payload and space that the Vatrta LFD 90’s deliver better value

 

[Ralph-n-Bev]

150 Ah Max discharge on the EZA pack.....Should manage with that.

eza.fr/en/eza130.html

 

[Ralph-n-Bev]

Just in case you change your mind @Robert Clark

Highly recommend these guys....https://store.meadotech.com

They even reply to emails late in the evening

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[Robert Clark]

Just in case you change your mind @Robert Clark

Highly recommend these guys....https://store.meadotech.com

They even reply to emails late in the evening

Thank you !
I used those guys to negotiate a lower price from another Victron online supplier for the kit I bought

 

[Lenny HB]

Hi Lenny, Can you say on what you base your opinion, I mean do you think he is mistaken,( I am sure he is not intentionally lying). I am just trying to get to the advantages and if he is wrong I would like to know why he is wrong, Its always nice to make an informed choice and I am looking for as much evidence based information as I can get.

Basic physics down to 22% that means he had to get 101 a/h back into the batteries in 20 mins, they may charge quicker but you have still got to replace 101 a/h where are you going to get that from with a standard alternator, to do it in the 20 min he claimed you would have to be charging at over 300 amps and that is not allowing for any losses in the charging circuit or cables.

I know one couple who have one and they love it and make similar claims - brainwashing comes to mind.
Before they had the Li battery they had a van with a couple of Gel batteries an a single either 80 or 100 w solar panel and they used to tell me they would charge both the electric bikes use the kettle & toaster off the inverter and the wife would dry her hair and the batteries were fully charged by lunchtime. They had no concept of how a Gel charges and that to get a full charge once it reaches it's charged voltage it need to stay they there for the absorption phase for at least 6 hours to be fully charged.
I know that is not that relevant I'm just trying to point out people are not aware of charging parameters of batteries and get fooled by their gauges just because it says a 100% doesn't necessarily mean it is.

 

[Gromett]

The battery project is currently on the back burner. But prices have fallen so much over the last 12 months I will be buying new.
https://www.ev-power.eu/Winston-40Ah-200Ah/

for instance 4 x 160Ah Winstons will be around the £600 mark. My existing Sterling charger will work with it, and I will be looking to upgrade to a Victron MPPT controller which also handles my requirements.

i will be creating my own simple BMS as I will be bottom balancing my batteries to prolong the lifespan.

Project is on the back burner at the moment as I have higher priority drains on my budget, However hoping to have this all in for next summer.

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[Pausim]

The BIG problem with the Victron batteries is that they only come with a 2 year guarantee, whereas the Varta’s come with 4 years

If length of guarantee is a factor the Relion (US make) sold by Alpha (UK) come with a ten year guarantee.
http://www.alpha-batteries.co.uk/leisure-batteries/?ab_construction=411

 

[Richard n Ann]

Let's hope they last longer than phone lithium batteries. My last one lasted 18 months before the capacity seemed to half.

 

[Wissel]

The battery project is currently on the back burner. But prices have fallen so much over the last 12 months I will be buying new.
https://www.ev-power.eu/Winston-40Ah-200Ah/

for instance 4 x 160Ah Winstons will be around the £600 mark. My existing Sterling charger will work with it, and I will be looking to upgrade to a Victron MPPT controller which also handles my requirements.

i will be creating my own simple BMS as I will be bottom balancing my batteries to prolong the lifespan.

Project is on the back burner at the moment as I have higher priority drains on my budget, However hoping to have this all in for next summer.

Seems we are on the same page Gromett

I still have to read up on bottom balancing, but how difficult would it be to create a bottom balancing BMS that monitored real time battery status and charging current?

Maybe something Arduino based with a simple LED display?

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[stewartwebr]

The way I see things, if multi billion companies such as Boeing who spent literally hundreds of millions in developing the Dreamliner can't get it right with lithium based batteries, https://www.scientificamerican.com/article/how-lithium-ion-batteries-grounded-the-dreamliner/, developed by one of the world leaders in battery technology (Yuasa), then I am damned if I would be prepared to trust my life or that of my family to the promises of a UK limited company (RoadPro)`whose recorded capitalisation is £1,000 and whose balance sheet wouldn't buy a modest motorhome (£86k positive in 2015 https://beta.companieshouse.gov.uk/company/01587959).

It's a rhetorical question, but I will ask it, whose record for investment in safety and design excellence are you likely to place greater trust in?

Technology is changing battery design very rapidly, it would appear that LiFePO4 technology - whose reputation for safety appears to remain under scrutiny - is likely to be supplanted very soon with the advent of lithium or sodium glass electrolytes (http://pubs.rsc.org/en/Content/ArticleLanding/2017/EE/C6EE02888H#!divAbstract) for mass storage, as described here: https://www.forbes.com/sites/jamesc...echnologies-keep-getting-better/#5fa5e6be4e62

There is an argument for just seizing the moment and buying a new technology in the knowledge that it has a limited span before it becomes inevitably redundant, companies such as Apple and Tesla are certainly exploiting that limited market to the full. But as sure as the once fashionable iPhone 6 in your pocket will end up where it belongs in the bin before too much longer, the battery technology of today is destined to become hopelessly obsolete within the next 5 years. Depreciation of 600 spondoolicks a year is a lot of moolah to pay for the privilege of being an early adopter. Heck, it even makes an iPhone X look like a bargain.

As I said before, if people want to buy into what is available today in the knowledge that there is better at lower cost around the corner, then good luck to them.

I guess I can see the argument you make. However, if it was not for the, "seize the moment types" you refer too, which I guess I'm one there would be no advancement. If none of the STM Types bought the iPhone 6 there would never be a 7, 8 etc. Where do you stop or even start, the world is moving at a huge pace with advancements in technology on a weekly basis. If you wait for the latest what ever you will never buy anything as what ever you buy is very soon obsolete within a short period of time. Make you choice spend your money, its personal choice.

 

[PeteH]

Just for the record. My Last R-V had 6 Lead acids. Serviced by a 40W "Smart" Charger,(already installed) and 3 x 100W Solar panels. I could run a 200W inverter off it. We used to last a week easy at Festivals. The only time I ran the Genny, was to Use the Old American 110V Microwave which was very high on consumption, for maybe 20min at any one time. The L-A`s cost less than £80 each and the panels set me back about £350 in total with a Solar regulator (£45). The whole kit was wired in using Welding Cable (free!, Don`t ask!) £875ish total for the whole rig. Heavy kit I realise, but we had both Payload and space.

 

[Gromett]

Seems we are on the same page Gromett

I still have to read up on bottom balancing, but how difficult would it be to create a bottom balancing BMS that monitored real time battery status and charging current?

Maybe something Arduino based with a simple LED display?

I haven't looked into it too much just yet due to other projects on the go at the moment. However off the top of my head, 4 inputs to monitor the voltage of each cell.
2 relays. One to cut off the charger if any cell went over voltage. The second to cut the battery bank off if it went under voltage. However it would also include warning methods to warn you when you were getting close to cut off voltage so you could reduce usage. At some future point in time I would probably like to add a shunt and create a simple coulomb counter as these are much more accurate on LiFePO4 batteries than on lead acid as Peukerts is not so much of an issue.

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[Neilfg]

Correct, he said he was down to 22%. He started the engine to make sure all was ok to start. Then charged it to 100% with a "20 odd mile" drive. I'll try it when I get the opportunity - soon I hope

Thanks for the info, I really like the speed of recharge and to me that is worth something, but there seems to be some conflicting views as to whether the claims for recharge are possible.

It seems we could build our own system but for most of us that is not an option, so as we are checking out possible options for a van and effectively the EZA option can be added and would cost us 1140.00 pounds extra.

Having read the threads, yourself and @Ovalball have it installed so if either of you get the chance I would love to know if you think you can really put back 30% or so in a 30 minute drive, engine and alternator info would be handy as well.

My only other concern is one of warranty and support if something fails do you think you could put a standard leisure battery in its place easily without specialist EZA knowledge?

 

[Wissel]

Thanks @Gromett

I think all that might be a bit beyond me at the moment. I'm sure I could learn it in time, just not sure I have the time right now with everything else going on in my head.

Think I'll plumb for an off the shelf BMS for now. Probably this one:
https://www.ev-power.eu/Battery-Man...-Complete-Set-4-cells-with-Bluetooth-4-0.html

I can set the upper and lower voltages on the conservative side, which should help right?

Then maybe down the line look at bottom balancing (as I can't seem to find an off the shelf bottom balancing solution).

Is there anything else you'd suggest I look at?

 

[Gromett]

@Wissel
If you pick a BMS that does top balancing I would look for one that allows you to set the top voltage. I would set this .1v below the recommended voltage for the battery. For the LVC I would set it a little higher than recommended. This does reduce the capacity of the battery however it will increase the lifespan of the battery by a big chunk.

LiFePO4 batteries hate being held at full charge, and they hate being held at empty.... So avoiding each end of the charge scale does increase their lifespan. It is also worth noting if you put the van into storage (for 3+ months) to get the battery to around 80% of capacity then disconnect if possible.

I cannot recommend a specific BMS as I have not looked into them in any great detail nor have I used any of them sorry.

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[two]

I haven't looked into it too much just yet due to other projects on the go at the moment. However off the top of my head, 4 inputs to monitor the voltage of each cell.
2 relays. One to cut off the charger if any cell went over voltage. The second to cut the battery bank off if it went under voltage. However it would also include warning methods to warn you when you were getting close to cut off voltage so you could reduce usage. At some future point in time I would probably like to add a shunt and create a simple coulomb counter as these are much more accurate on LiFePO4 batteries than on lead acid as Peukerts is not so much of an issue.

To obtain more scientific information, I'd put coulomb counters on each of the different inputs. It'd be interesting to to know what contributions the different sources of power actually make. There's far too much opinion and far too little measurement regarding the use of 12V electricity. I have tried to take measurements but then discovered flaws in my method, but it's better than the Kentucky Windage method adopted by some.

 

[Gromett]

Please note. I am not an expert on LiFePO4 batteries and my comments above and in the PM are based on my research and not my experiments...
I do intend to buy a set of small LiFePO4 batteries to experiment with in my trailer for my freezer etc as a little test bench before rolling out the large system to my van.

 

[ChrisL]

Some new top of the range motorhomes come with LiFePO4 batteries now, the Frankia Platinum range have the following as standard, one assumes they must be fairly confident at least in terms of reliability to be installing these.

• Inverter MT 1700 Si-K / Sinus (Büttner)
• 4x solar system 100 W (Buttner) with solar remote display
• Solarregler MT 550 PP (Büttner)
• Control MT 4000-H (hybrid battery computer from Büttner)
• LiFePO4 Batterie 2 x 110 Ah

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[dabhand]

The way I see things, if multi billion companies such as Boeing who spent literally hundreds of millions in developing the Dreamliner can't get it right with lithium based batteries, https://www.scientificamerican.com/article/how-lithium-ion-batteries-grounded-the-dreamliner/, developed by one of the world leaders in battery technology (Yuasa), then I am damned if I would be prepared to trust my life or that of my family to the promises of a UK limited company (RoadPro)`whose recorded capitalisation is £1,000 and whose balance sheet wouldn't buy a modest motorhome (£86k positive in 2015 https://beta.companieshouse.gov.uk/company/01587959).

It's a rhetorical question, but I will ask it, whose record for investment in safety and design excellence are you likely to place greater trust in?

Technology is changing battery design very rapidly, it would appear that LiFePO4 technology - whose reputation for safety appears to remain under scrutiny - is likely to be supplanted very soon with the advent of lithium or sodium glass electrolytes (http://pubs.rsc.org/en/Content/ArticleLanding/2017/EE/C6EE02888H#!divAbstract) for mass storage, as described here: https://www.forbes.com/sites/jamesc...echnologies-keep-getting-better/#5fa5e6be4e62

There is an argument for just seizing the moment and buying a new technology in the knowledge that it has a limited span before it becomes inevitably redundant, companies such as Apple and Tesla are certainly exploiting that limited market to the full. But as sure as the once fashionable iPhone 6 in your pocket will end up where it belongs in the bin before too much longer, the battery technology of today is destined to become hopelessly obsolete within the next 5 years. Depreciation of 600 spondoolicks a year is a lot of moolah to pay for the privilege of being an early adopter. Heck, it even makes an iPhone X look like a bargain.

As I said before, if people want to buy into what is available today in the knowledge that there is better at lower cost around the corner, then good luck to them.

Anybody want to buy an iPhone 6?

 

[olley]

3 grand for a battery!! your bonkers..................................................However having spent more than that on some useless, and some not so useless bits of kit on my RV over the years, my opinion is a bit suspect.

Enjoy.

 

[dabhand]

I still have to read up on bottom balancing, but how difficult would it be to create a bottom balancing BMS that monitored real time battery status and charging current?

Is this about sex toys?

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[two]

I’m not sure what the EZA electronics do in terms of stabilising the voltage presented to the rest of the vehicle. I think that the natural voltage of (four cells of) LiFePO4 is 12.8V which is close to a fully charged Lead Acid battery. What can harm some 12V devices, though, is the voltage applied during charging. If EZA shields the habitation circuit from high (or very low) voltages, it may be that the use of such a system could prolong the lives of the equipment using it.

 

[Gromett]

I’m not sure what the EZA electronics do in terms of stabilising the voltage presented to the rest of the vehicle. I think that the natural voltage of (four cells of) LiFePO4 is 12.8V which is close to a fully charged Lead Acid battery. What can harm some 12V devices, though, is the voltage applied during charging. If EZA shields the habitation circuit from high (or very low) voltages, it may be that the use of such a system could prolong the lives of the equipment using it.

You are correct to a point....

The output voltage for LiFePO4 cells varies .1v or .2v depending on manufacturer. The great thing about them though is that they start off at their charge voltage and within a few % of 100% they fall to their nominal voltage and maintain this voltage for the bulk of the discharge cycle. This varies between manufacturer/specific chemistry but roughly speaking from 95% SOC down to around 20% state of charge the voltage remains the same. This is nothing like Pb batteries where you can get a rough idea of the State of Charge (SoC) by measuring the open circuit voltage.

Here is the main point. You do NOT keep a LiFePO4 battery on float like you do a lead acid. A lead acid will float at between 12.8 and 13.1v depending on the charger/battery.
So from my perspective you don't have to change anything, as the LiFePO4 will operate at the same voltage that the Pb batteries will float at. Therefore if you have any equipment that would fail at 12.8 then it will also fail on Pb Float.

I came to a conclusion that my LED lighting was being damaged by the long term float charge when on hookup (with Pb batteries). So I installed a 12V regulator for the lighting circuit. Now the LEDs get exactly 12v and everything else gets the full float voltage.

This I think is an advantage for things like the water pump. I like it when the battery charger kicks in when having a shower and puts the voltage up to 14.5V as it gives me a slightly higher flow rate .




The other thing I like about LiFePO4 cells is that when under load the voltage dips a little immediately but quickly recovers to nominal. Where a Pb battery will see the voltage slowly sag lower and lower. You can see this most visibly when you start your vehicle if you have a volt meter monitoring it. You will see the voltage (on my van) slump from 12.x V down to as low as 9v when cranking and won't recover until you stop cranking. It will continue to rise for a while after cranking stops. On a LiFePO4 battery it will drop for a very small period but recover even while cranking.

What this means for me is that the output voltage of LiFePO4 cells tends to be a lot more predictable even under load. This is great for things like inverters because power = V X A. If voltage drops then A has to increase proportional to give the same power. Losses are related to current. So the fact that LiFePO4 batteries keep their voltage more stable means lower amperage pulled under high loads for the same power and less losses.

 

[Gromett]

PS: for those non techies. The above about power loss is why power transmission lines use high voltages such as 44KV. This is very high voltage but much lower current to transfer the same amount of power. They do this to reduce losses in transmission which is directly related to current. They then step this down to the 240V at a substation near your house as this is a much safer voltage to handle for domestic products.

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