My New Battery Setup for Full-Timing - LifePO4 - Build Log (2 Viewers)

[Gromett]

From that PDF

As you can see the improvements in capacity seem to level off at around 20°C

 

[Wissel]

Think that's all the major cables etc fitted, just need to heat shrink the ends when it arrives tomorrow. The BMS is being fitted in morning, then charger programmed for initial fuller charge. If all goes to plan I'll be able to reduce the charge voltage 24 hours later and it will all be working. Fingers crossed

The wiring is a 50mm cable from the battery to master fuse then isolator switch. Here it splits to a 50mm cable powering the feeds and a 25mm cable to handle the charging.

The blue things around these wires are current sensors and are part of the BMS. When the system is active I'll get three figures on my phone app. One showing the actual power in my battery, one showing charge current and one showing power usage. These are all accurate and in real time.

The 50mm cable then runs to a smart relay. This is controlled via the BMS, so if it detects to much draw on the cells it can shut down before any damage. The relay is a dual setup with one side controlling the 12v electrics and the other the inverter. The yellow wires are ready to connect the BMS to the relay.

Likewise, the 25mm cable runs to the charger (via a fuse) along with a signal wire to allow the BMS to switch charging on and off as needed.

Finally, the box in the middle is a distribution box for the 12v electrics. This splits off to three separate fuse boards around the van, each with their own negative busbar.

 

[Gazz Kaz+Spag]

I was going to look at doing this myself but after reading your last my heads is a shed so I may have to seek a supporter

Its looking damn good !

 

[StitchesnFluff]

What a great job! Thanks for sharing

 

[Wissel]

I was going to look at doing this myself but after reading your last my heads is a shed so I may have to seek a supporter

Its looking damn good !

It's not as complicated as I may have made it seem. No different to a descent high power lead acid setup with a battery protect. Until the BMS goes in (which isn't that complicated I hope).

Even the cables wouldn't need to be so big if I'd have fitted the charger and inverter nearer the battery, but I wanted these under the drivers seat for ventilation (about 3m away).

Thing is this gives us roughly the equivalent of 7 x 100Ah lead acid batteries in a much smaller and lighter package with faster and more efficient charging and accurate monitoring. Hopefully once fitted I can forget about it for years and it just works

It's obviously a setup that most would never need, but for us I'm convinced it's the best solution. We should have as close to home electrics as practical in a van. With the 12v, low-power, PC always on and the compressor fridge, we shouldn't need anything other than solar and a short drive most of the year to keep topped up and the Tassimo running. Hopefully

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[Wissel]

It's finally working



Be warned - this is a long and boring video for anyone not installing a similar system. I've tried to show the whole installation - a lot of it in real time.

So pleased this is now working and I can get on with something else

 

[Gazz Kaz+Spag]

Looking good there...……. ive still a few bits to get my charger came yesterday

 

[Wissel]

Looking good there...……. ive still a few bits to get my charger came yesterday

Thanks

What do you think to the charger? Was really impressed with the build quality. Also the easiest thing to set and wire in whole install

 

[Gazz Kaz+Spag]

Yes same here just need to work out taking old electro block out to replace it. I want to be able to put it back in though when I move on into the next MH so trying to make it easy

 

[Gromett]

Just watched video. Nice one.. I am looking forward to doing mine

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[DBK]

It's not as complicated as I may have made it seem. No different to a descent high power lead acid setup with a battery protect. Until the BMS goes in (which isn't that complicated I hope).

Even the cables wouldn't need to be so big if I'd have fitted the charger and inverter nearer the battery, but I wanted these under the drivers seat for ventilation (about 3m away).

Thing is this gives us roughly the equivalent of 7 x 100Ah lead acid batteries in a much smaller and lighter package with faster and more efficient charging and accurate monitoring. Hopefully once fitted I can forget about it for years and it just works

It's obviously a setup that most would never need, but for us I'm convinced it's the best solution. We should have as close to home electrics as practical in a van. With the 12v, low-power, PC always on and the compressor fridge, we shouldn't need anything other than solar and a short drive most of the year to keep topped up and the Tassimo running. Hopefully

I'm a bit puzzled by your Ah figures. Is each cell a 100Ah 3.2v one like the link Grommet posted on the previous page?

 

[Gazz Kaz+Spag]

Yes each of the 4 cells are 400Ah 3.2v.

 

[DBK]

Yes each of the 4 cells are 100Ah 3.2v.

That's what I thought. Wired in series they make a 12.8 volt 100Ah battery, not 400Ah. You would only get 400Ah if you wired them in parallel but then it would only produce 3.2 volts which isn't a lot of use.

 

[Wissel]

That's what I thought. Wired in series they make a 12.8 volt 100Ah battery, not 400Ah. You would only get 400Ah if you wired them in parallel but then it would only produce 3.2 volts which isn't a lot of use.

My cells are 400Ah 3.2v each

I conservatively estimate I have around 360Ah usable, hence around the same as 700Ah lead acid.

 

[DBK]

My cells are 400Ah 3.2v each

I conservatively estimate I have around 360Ah usable, hence around the same as 700Ah lead acid.

That makes sense. Thanks.

Edit. I should have looked at the first page of this Thread. Doh!

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[Gromett]

Yes each of the 4 cells are 100Ah 3.2v.

I was going to say they look a bit big for 100Ah Li cells. They look more like 400Ah.. But beaten to it

 

[Gromett]

I conservatively estimate I have around 360Ah usable, hence around the same as 700Ah lead acid.

And use a lot less space, weigh a lot less and will last a lot longer

 

[Gazz Kaz+Spag]

lol I typo errored myself......400Ah each

 

[Gromett]

Not directly related but tangentially related.

I bought a Galaxy Note 2 back in early 2013 (5 and a half years ish).. I am still on the original battery and it lasts me just under 2 days. That is how long a well looked after Li battery can last.
And that goes through a full charge/discharge cycle every 2 days or so. I estimate that is around 1,200 full cycles.

Check the date 2012.12.22

If I didn't cycle it all the way from full to flat and back again, I could extend the lifespan even more.

As it happens. I saw a great deal on a replacement battery for it last week and have just ordered one. This will allow me to get back up to the full 2 days between charges..

I love Li cells. Worth noting that the batteries that @Wissel is using and what I intend to use are LiFePO4 not the cobalt variety. This means they have a much much longer lifespan, aren't prone to flame outs etc... The cobalt variety have a much higher energy density which is required for compact applications like phones. But LiFePO4 are not quite so energy dense but gain a longer lifespan..

 

[DBK]

A comment in an article this morning about the Lancaster University work on a possible significant improvement to Lithium batteries was interesting. It was a kilogram of petrol produces about 100 times the energy as a kilogram of the best battery available today.

So the answer is a Genny!

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[tonyidle]

A comment in an article this morning about the Lancaster University work on a possible significant improvement to Lithium batteries was interesting. It was a kilogram of petrol produces about 100 times the energy as a kilogram of the best battery available today.

So the answer is a Genny!

No it isn't - the engine wastes 80%+ of the energy from the petrol. The generator part probably wastes 80% of the remainder .

 

[Gromett]

A comment in an article this morning about the Lancaster University work on a possible significant improvement to Lithium batteries was interesting. It was a kilogram of petrol produces about 100 times the energy as a kilogram of the best battery available today.

So the answer is a Genny!

Plutonium produces (insert figure here) times the power of petrol....
Lets put a nuclear reactor in the van instead of a genny

Energy density is not the only metric...

 

[Pausim]

Yes same here just need to work out taking old electro block out to replace it. I want to be able to put it back in though when I move on into the next MH so trying to make it easy

Not sure which Elekroblock you have but with my 29 Udo Lang at Schaudt advised keeping it for eveything except charging. He suggested simply removing the 20 amp charging fuse from it and wiring my LiFePO4 friendly mains charger directly to the battery. For the battery to battery charger it was just a matter of intercepting the engine battery feed before it entered the Elektroblock. He said the advantage was the Elektroblock could still trickle charge the engine battery when on mains and the mains connection light would still function.

 

[Robert Clark]

Can I please ask about charging voltages / regime for Lithium?

Reading a LifePO4 data sheet it talks about Charge Voltage 14.2 - 14.6v
And a balancing voltage of 14.4v

When setting up a charger would you set 14.6v as the absorb voltage and 14.4v as the float?
And if so, how long would the absorb time be?

Thanks

 

[Gromett]

Can I please ask about charging voltages / regime for Lithium?

Reading a LifePO4 data sheet it talks about Charge Voltage 14.2 - 14.6v
And a balancing voltage of 14.4v

When setting up a charger would you set 14.6v as the absorb voltage and 14.4v as the float?
And if so, how long would the absorb time be?

Thanks

There is no absorb time with an an Li battery, it is a simple CC/CV charge. Float should be below the maximum charge voltage, the lower (to a point) the longer the lifespan but the less the actual capacity.

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[Robert Clark]

There is no absorb time with an an Li battery, it is a simple CC/CV charge. Float should be below the maximum charge voltage, the lower (to a point) the longer the lifespan but the less the actual capacity.

Thanks
What would you set the lower voltage at?
Would 14.4 v be ok or would you suggest lower?

 

[JJ]

Full time for thirty odd years (off site... not plugged in) and have managed ok with a couple of batteries (normal) and two or three solar panels...

Plus a genny for when folk park too close.

Of course, I am living alone and have adapted to "van life", rather than trying to live a "bricks and mortar" life in a van...


JJ

 

[Gromett]

Thanks
What would you set the lower voltage at?
Would 14.4 v be ok or would you suggest lower?

It depends on a variety of things. The cells you are using, the maintenance mode (top balance or bottom balance) plus a few other things. There is no one fixed value sorry
@Wissel could probably talk you through his configuration based on his set up though.

I will probably be going with these or the 400Ah version of these;
https://www.ev-power.eu/Winston-40A...IDE.html?force_sid=fpilb738a1co5q2llk0cftkt50

The specs for these are;

Nominal voltage of the cell is 3,2 V and the operational voltage is 2,8 V - 3,8 V.
The maximum charging voltage for initial charge is 4 V.
Recommended subsequent charging is to 3.8 V.
The minimum voltage is 2.5 V.

The operational voltage range is 2.8 to 3.8. You need 4 to make a bank. which gives an operational range of 11.2V to 15.2V.
I am personally going to be bottom ballancing mine which reduces the available capacity but extends lifespan. So I would operate at the 3v - 3.6v range. Giving 12v to 14.4V for the battery bank as a whole. This matches in with my current lead acid battery range pretty closes. For float though I would set this at around 14.2v initially and increase it gradually based on the results of balancing over time.

Not an easy question to answer sorry

PS: ignore my figures, I think I have them wrong... I did them from memory. I will dig out my notes later when I finish work...

 

[Robert Clark]

It depends on a variety of things. The cells you are using, the maintenance mode (top balance or bottom balance) plus a few other things. There is no one fixed value sorry
@Wissel could probably talk you through his configuration based on his set up though.

I will probably be going with these or the 400Ah version of these;
https://www.ev-power.eu/Winston-40A...IDE.html?force_sid=fpilb738a1co5q2llk0cftkt50

The specs for these are;


The operational voltage range is 2.8 to 3.8. You need 4 to make a bank. which gives an operational range of 11.2V to 15.2V.
I am personally going to be bottom ballancing mine which reduces the available capacity but extends lifespan. So I would operate at the 3v - 3.6v range. Giving 12v to 14.4V for the battery bank as a whole. This matches in with my current lead acid battery range pretty closes. For float though I would set this at around 14.2v initially and increase it gradually based on the results of balancing over time.

Not an easy question to answer sorry

PS: ignore my figures, I think I have them wrong... I did them from memory. I will dig out my notes later when I finish work...

I'm thinking of using Relion RB100's which only give two voltages
Charge voltage 14.2 - 14.6v
Balancing voltage 14.4v

 

[sallylillian]

T

I'm thinking of using Relion RB100's which only give two voltages
Charge voltage 14.2 - 14.6v
Balancing voltage 14.4v

Robert, your Victron inverter/charger has a Lithium charging profile, which can be adapted through VE config.

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