Buyer's remorse

[Langtoftlad]

So @ 240v 650w how long would that last ,?

Sorry don't understand.
The only test I've done is a Tassimo for a coffee drawing 1254w took 15% IIRC.
(or maybe that was the airfryer doing bacon )

Perhaps it's the wrong question.
It's a 105ah lithium battery with a 1500w inverter... does that help?

I'm happy to try any specific use.

 

[Langtoftlad]

Allowing for inverter inefficency and discharging from 100% down to 20% approx 1.3 hours.

This afternoon, I'll experiment using it as Pseudo EHU.
But being realistic/practical I'll put the fridge & hot water on gas.

 

[andykim]

OK, not powered fully by solar, by the batteries. I understand the idea will be to make use of stuff and reduce energy use, but remember that every time you use them this way you are deeply cycling (and very slowly degrading) your lithium batteries. Have you considered this?

You should get 1500-2000 deep cycles before 20% capacity loss from a half decent modern lithium, this is normally the point where degradation begins to accelerate thus it’s generally considered the ‘worn out’ point.

A ~ 800W condenser dryer will use 2kwhr on a typical 2.5hr cycle (they are slow, we have one). At 12V that’s 170ah with no invertor losses, or close on the full 200ah if the invertor efficiency losses are factored in (i guess this is where your solar may be helping out)

Thus to run your drier for a full 2.5hrs you will absolutely consume your full 200ah of capacity regularly going beyond the min 20% point particularly if the sun is behind cloud during the cycle. You will thus often be completely flattening the batteries on a full cycle.

Your bank is 200ah, and if we assume you paid, let’s say, £1000 for it and we assume that at this ultra heavy cycle use it will be worn out in 1700 cycles (if often discharged beyond the min 20% during cycling, they won’t even last this long, maybe 1250cycles).

Thus, each run is actually costing you between roughly 60p and 80p in terms of the degradation to your camper’s lithiums, which is broadly what you’d pay for 2kwhr of metered electric. Also remember you are also cycling your invertor.

WOW my head just exploded!!! I can just fathom how to change a plug

 

[dawsey]

WOW my head just exploded!!! I can just fathom how to change a plug

yeah sorry. I just wanted to make the point that lithium batteries, like anything else, are consumable and will wear out with use.

Just the same as lead acid batteries, the deeper they are discharged, the faster they wear out. It’s important not to completely flatten your lithium batteries, as they might wear out much faster that you might imagine - and they as we all know are very expensive.

The guidance is not to let them go below 20%. Do that and they will indeed last most of us out.

Discharging “to 80%” is 20% DoD or ‘depth of discharge’ and means absolutely nothing. Now read the advert for that power station….

Discharging “to 20%” remaining is 80% DoD or ‘depth of discharge’. 80% DoD is one of the standard aging tests of batteries.

Note the graphic below. You will see that lead acid batteries, if only cycled at 30% DoD will last just as long as modern lithium polymer batteries that are cycled at 80% DoD. In this way, I could, as a seller of Lead Acid batteries, claim that my batteries will last the same 2000 cycles as a lithium ferrous polymer battery - “to 70%”

But look at what happens to Lead acid battery cycle life if you more deeply discharge them….
(y-axis is remaining battery capacity, scale is 60-100%)

Thus, the other point was about being wary of what people who are trying to sell you something tell you about the thing they want to sell you (ie advertising).

 

[WESTY66]

WOW my head just exploded!!! I can just fathom how to change a plug

You can change a plug?? that’s one up on me

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[daveclare]

You're right about motorhoming not being cheap. Far from it. We have learned a lot in our two years of motorhoming. Not just from experience, but from others on here. Just wanting the freedom an inverter gives you sounds like a great idea in theory.

In Spain, during January/February this year, we realised that to truly wild camp with AC, air fryer, microwave and Dyson hair dryer, we needed not just an inverter, but more battery and solar. So 500w of solar, 3000w inverter and additional 230ah lithium was added to the list. I also like tools to do the job. So add in an hydraulic crimper, better circuit tester, amongst other bits. Then when you add cabling, switching, fuses and circuit protection to the list, it suddenly goes north of £2000. I wouldn't dream of allowing a dealer anywhere near our precious MH to do it. After their horrendous attempt at wiring in the 12v TV supply.

In reality it's cost thousands not having to pay for electricity every again. To use all of the appliances we want to. As long as we have some sun. Which on the face of it sounds ludicrous to some. It's true that in the six weeks we've been away. We've probably saved €200-300 in site electric charges.

But most importantly (to us) it gives us the freedom to go anywhere and use everything in the mh. From a car park in the middle of Modena, to a deserted beach in Almeria and everywhere else in between.

That's priceless.

Whether we do the right or wrong thing. There will always be a difference of opinion afterwards. However, we thought it was the right thing to do at the time.

 

[funflair]

Sorry don't understand. Mislead?
Are you saying that Anker's specification is factually incorrect?

3000 cycles 1 per day is about 10 years.

Real world 1 cycle a week, it'll outlive me...

From my understanding dawsey is suggesting that the claimed 3000 cycle lifespan is based on not discharging lower than 80% capacity, or in other words just using the top 20% and then recharging, maybe the question is what would the cycle number be if regularly discharged to 20% remaining.

I will add that when our last battery was added the system was checked and the tech guy confirmed that they had completed something like 13 full cycles in 2 years.

 

[dawsey]

You're right about motorhoming not being cheap. Far from it. We have learned a lot in our two years of motorhoming. Not just from experience, but from others on here. Just wanting the freedom an inverter gives you sounds like a great idea in theory.

In Spain, during January/February this year, we realised that to truly wild camp with AC, air fryer, microwave and Dyson hair dryer, we needed not just an inverter, but more battery and solar. So 500w of solar, 3000w inverter and additional 230ah lithium was added to the list. I also like tools to do the job. So add in an hydraulic crimper, better circuit tester, amongst other bits. Then when you add cabling, switching, fuses and circuit protection to the list, it suddenly goes north of £2000. I wouldn't dream of allowing a dealer anywhere near our precious MH to do it. After their horrendous attempt at wiring in the 12v TV supply.

In reality it's cost thousands not having to pay for electricity every again. To use all of the appliances we want to. As long as we have some sun. Which on the face of it sounds ludicrous to some. It's true that in the six weeks we've been away. We've probably saved €200-300 in site electric charges.

But most importantly (to us) it gives us the freedom to go anywhere and use everything in the mh. From a car park in the middle of Modena, to a deserted beach in Almeria and everywhere else in between.

That's priceless.

Whether we do the right or wrong thing. There will always be a difference of opinion afterwards. However, we thought it was the right thing to do at the time.

Completely agree with this. I did exactly the same, it cost the same and we use the camper in the same way. We even use the system to power a reverse osmosis filtration system to extract water from rivers or lakes when we can’t find a tap in winter

 

[Langtoftlad]

Ok, as long as you are happy.

Yes I'm happy
Is the laboratory derived specification achievable in real life?
Who knows, who cares ?
Is it about 6x better 5han the previous generation - yes
Is there any current battery technology that does it better be it powerbanks or fitted lithium batteries?

Does anyone care as long the specification is standard and can be compared with other brands in the same market?

 

[Langtoftlad]

I will add that when our last battery was added the system was checked and the tech guy confirmed that they had completed something like 13 full cycles in 2 years.

Precisely
1000, 2000, 3000 it matters not a jot.
It will outlast you or I
...and be good until the next generation of battery technology comes along.

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[funflair]

yeah sorry. I just wanted to make the point that lithium batteries, like anything else, are consumable and will wear out with use.

Just the same as lead acid batteries, the deeper they are discharged, the faster they wear out. It’s important not to completely flatten your lithium batteries, as they might wear out much faster that you might imagine - and they as we all know are very expensive.

The guidance is not to let them go below 20%. Do that and they will indeed last most of us out.

Discharging “to 80%” is 20% DoD or ‘depth of discharge’ and means absolutely nothing. Now read the advert for that power station….

Discharging “to 20%” remaining is 80% DoD or ‘depth of discharge’. 80% DoD is one of the standard aging tests of batteries.

Note the graphic below. You will see that lead acid batteries, if only cycled at 30% DoD will last just as long as modern lithium polymer batteries that are cycled at 80% DoD. In this way, I could, as a seller of Lead Acid batteries, claim that my batteries will last the same 2000 cycles as a lithium ferrous polymer battery - “to 70%”

But look at what happens to Lead acid battery cycle life if you more deeply discharge them….
(y-axis is remaining battery capacity, scale is 60-100%)
View attachment 771748

Thus, the other point was about being wary of what people who are trying to sell you something tell you about the thing they want to sell you (ie advertising).

I am not convinced by your interpretation of that graph, firstly a lead acid DOD 30% will not last the same as LiFePO4 to DOD 80% the angle of the line is clearly different and the graph needs extending to see where they both finish, secondly I really don't understand the 2000 cycles figure as taking a LiFePO4 to just 70% will as you say increase it's cycles even further.

 

[Tombola]

You know sometimes when a thread gets too complicated and into minute details...and you just doze off a bit..well....

 

[dawsey]

I am not convinced by your interpretation of that graph, firstly a lead acid DOD 30% will not last the same as LiFePO4 to DOD 80% the angle of the line is clearly different and the graph needs extending to see where they both finish, secondly I really don't understand the 2000 cycles figure as taking a LiFePO4 to just 70% will as you say increase it's cycles even further.

Yes the line is slightly lower, however I was just using the data in the plot to reinforce the point about how DoD affects cycle life.

 

[Barclaybasher]

You know sometimes when a thread gets too complicated and into minute details...and you just doze off a bit..well....

I've had 4 vans first (coachbuilt) had no hab battery just the engine - lead acid.
Next 3 including present van 1 hab battery (all lead acid)
Last 2 vans had a single solar panel.
I don't need more.
I do carry a spare battery and jump leads - never had to use them - so far

 

[GMLS]

In my list of why the Anker 757 is a good investment, I hadn't even considered the UPS or power cut at home scenario

Had to use my Anker767 unexpectedly within days of purchasing it for a back up. Completely saved the day as the family fridge freezer was full of food for a wake the next day and the mains power was off a long time

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[andykim]

yeah sorry. I just wanted to make the point that lithium batteries, like anything else, are consumable and will wear out with use.

Just the same as lead acid batteries, the deeper they are discharged, the faster they wear out. It’s important not to completely flatten your lithium batteries, as they might wear out much faster that you might imagine - and they as we all know are very expensive.

The guidance is not to let them go below 20%. Do that and they will indeed last most of us out.

Discharging “to 80%” is 20% DoD or ‘depth of discharge’ and means absolutely nothing. Now read the advert for that power station….

Discharging “to 20%” remaining is 80% DoD or ‘depth of discharge’. 80% DoD is one of the standard aging tests of batteries.

Note the graphic below. You will see that lead acid batteries, if only cycled at 30% DoD will last just as long as modern lithium polymer batteries that are cycled at 80% DoD. In this way, I could, as a seller of Lead Acid batteries, claim that my batteries will last the same 2000 cycles as a lithium ferrous polymer battery - “to 70%”

But look at what happens to Lead acid battery cycle life if you more deeply discharge them….
(y-axis is remaining battery capacity, scale is 60-100%)
View attachment 771748

Thus, the other point was about being wary of what people who are trying to sell you something tell you about the thing they want to sell you (ie advertising).

I don't even get the "offside" rule.

 

[funflair]

I don't even get the "offside" rule.

Now some things just aren't interesting enough to even try to understand

 

[Cush]

Having installed my inverter I'm now wondering if I did the right thing. So far I've spent about £300, my battery is not large enough to power it anywhere near it's full 2kw and is overloaded even for the 500w I will use. To run it correctly, just for the 500w, I need a second battery, battery box and extra cable and terminals. For the full 2000w I need lithium and new chargers as well as more solar, the costs keep going up. I could have bought a power bank for around £1,500 this would need no extra wiring and could be used outside the van as well.
Did I do the right thing?

Always back yourself. If you are going to keep the van, don’t have anything that needs a back up at home, will end up spending a load of money anyway, have no storage charging issues and it won’t cost a lot to get installed I’d get the infrastructure you describe.

if You don’t know how long you’ll keep the van. Have crappy lead acids and a crappy charger, no solar / ehu in storage and like the simplicity of it then I’d do the research in to the power banks. You could always put the inverter in classifieds. (I’ll be going down the power bank route when it’s time)