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

[Dazzlin]

Is there any reason why you could not crimp, then dollop solder to fill the gaps, to strengthen, and improve conduction?

Was thinking about this the other day....

 

[Gromett]

Is there any reason why you could not crimp, then dollop solder to fill the gaps, to strengthen, and improve conduction?

Was thinking about this the other day....

If crimped properly the solder wouldn't add anything to the connection as it would not be able to flow into the cable conductors at all. on the cable side of the crimp it may flow up the cable causing a stress point as described above. This is definitely one of those do one or the other not both.

And DEFINITELY do not solder then crimp. That is absolutely asking for trouble.

 

[Wissel]

Thanks @Gromett

I think what I'll do is have a good look at my old cables and test their resistance. If they are still perfect after 5 years I'll stick with soldering (as you say, a widely debated topic).

My reason for this is I'm better at soldering than crimping - plus have the tools to solder already.

If it turns out my old leads do show any issues with either resistance or any sign of looseness I'll order the crimper you suggested. Thanks again, David

^{_{Subscribers  do not see these advertisements}}

 

[Gromett]

Thanks @Gromett

I think what I'll do is have a good look at my old cables and test their resistance. If they are still perfect after 5 years I'll stick with soldering (as you say, a widely debated topic).

My reason for this is I'm better at soldering than crimping - plus have the tools to solder already.

If it turns out my old leads do show any issues with either resistance or any sign of looseness I'll order the crimper you suggested. Thanks again, David

I wasn't trying to convince you to go the crimp route. If you are happy with soldering stick to it.

I also prefer crimping large cables as it is faster and easier. For a £15 tool I can now do connections in a few seconds rather than all the faffing about with soldering. Messy flux, getting things up to temp, post soldering cleanup. Then waiting for things to cool down... I can do crimp connections so much quicker..

I leave my soldering to my electronics projects

 

[The Wino]

Just a though could you plug into a vehicle charging point with an adapter a bit cheeky though!

 

[autorouter]

Is there any reason why you could not crimp, then dollop solder to fill the gaps, to strengthen, and improve conduction?

For wiring, a vehicle is a very different environment from a building. For a start, stranded wire is used, not solid twin-and-earth-style house wires. Vibration long-term will cause stress-cracking at any stress point. Any abrupt change in the material is a potential stress point.

Solder tends to flow between all the strands, and end at a definite point, which is then a stress point. A crimp is a bit more spread out.

It's not just opinion. Thousands of hours of vibration testing has confirmed this. Joints in aircraft are always crimped. The Audi service manual I used the other day specifically states that joints in the wiring loom are not to be soldered.

I am competent at soldering, including surface mount circuit boards using a microscope, and have all the soldering gear, but I would never use solder joints in car wiring. Maybe for motor brushes, if that's the only option.

Also important for reliability is heat-shrink tubing around the joint to support it, and support with wrapping/cable ties/trunking to minimise vibration.

^{_{Subscribers  do not see these advertisements}}

 

[Richard n Ann]

I made a crimp once out of 1 1/8" copper pipe...

Crimped the cable in then soldered it and heat shrank the crimped bit. Might not look very nice but I don't see it anyway. Used my 100w antex iron which will solder anything

 

[Wissel]

Well that's a few people now all telling me crimping is a better option.
I'll order the crimper now

Thanks all.

 

[Gromett]

I made a crimp once out of 1 1/8" copper pipe...
View attachment 219725
Crimped the cable in then soldered it and heat shrank the crimped bit. Might not look very nice but I don't see it anyway. Used my 100w antex iron which will solder anything

If you cut a piece of 15mm copper pipe to the right length then hammer one half flat it makes a good 50mm² crimp blank. You can then drill whatever size hole you want from M-8, M-10 etc.
You do need to wire wool the inside before crimping to ensure you get a clean connection. It is possible that tinning these before use might be a good idea.

I have never done this however. I keep a good stock of most common sizes I use. Including the larger unsleeved ones as well as the small red/blue/yellow types.

My storage box contains loads of stuff that I used on the self build. Circlips, E-Clips, O rings, plumping and gas fittings, full set of fuses, bulb, crimps, self tapping screws, wood screws, jubilee clips, stainless steel nuts/bolts/washers, Rivnuts (excellent) and P-clips. That is just my hardware drawer. As a fulltimer you have to be prepared for every eventuality
It's those little things that break when on the road that can cause the most issues. Having a full collection of spares along with spare pipe and cable can change a major catastrophe into a minor breakdown...

Whenever I need some hardware, I always look for large kits of the things instead of just buying the one size I need.. I end up with loads of stuff I never use, but after 9 years on the road I now have everything I will ever need .

^{_{Subscribers  do not see these advertisements}}

 

[Robert Clark]

Have you seen these on EBAY?

http://r.ebay.com/3E2kPf

Wondering if anyone has any opinion on these?

£700 for a 100ah battery seems very cheap to me

 

[Pausim]

Have you seen these on EBAY?

http://r.ebay.com/3E2kPf

Wondering if anyone has any opinion on these?

£700 for a 100ah battery seems very cheap to me

For £200 more you can get one from a known manufacturer with a 5 year warranty. I thought about one of the ebay ones but decided I would rather pay more for one with a known reputation and good after sales support. I went for a Relion RB100.

 

[Robert Clark]

For £200 more you can get one from a known manufacturer with a 5 year warranty. I thought about one of the ebay ones but decided I would rather pay more for one with a known reputation and good after sales support. I went for a Relion RB100.

May I ask who you purchased from?

^{_{Subscribers  do not see these advertisements}}

 

[Pausim]

May I ask who you purchased from?

I bought it from Alpha Batteries, negotiated a bit of a discount on the phone.

 

[Robert Clark]

I bought it from Alpha Batteries, negotiated a bit of a discount on the phone.

Did you use a battery management system, or is this built into the battery?

 

[Gromett]

Have you seen these on EBAY?

http://r.ebay.com/3E2kPf

Wondering if anyone has any opinion on these?

£700 for a 100ah battery seems very cheap to me

4 of these https://www.ev-power.eu/Winston-40Ah-200Ah/WB-LYP100AHA-LiFeYPO4-3-2V-100Ah-WIDE.html
Are less than £400 and give you 100AH..

Doesn't look that cheap to me @ £679?

^{_{Subscribers  do not see these advertisements}}

 

[Robert Clark]

4 of these https://www.ev-power.eu/Winston-40Ah-200Ah/WB-LYP100AHA-LiFeYPO4-3-2V-100Ah-WIDE.html
Are less than £400 and give you 100AH..

Doesn't look that cheap to me @ £679?

Im guessing though that you'd need to build your own management system, which would increase the cost?

 

[Pausim]

Did you use a battery management system, or is this built into the battery?

Built in BMS. Here are a few more details https://www.solacity.com/docs/RELiON/RELiON_Cell_Features_and_Design.pdf
It even isolates individual cells if they are hit by bullets. Only the Americans would see this as a selling point. I said in an earlier link that if someone is firing at me I will be concentrating on bowel control not on damage to my leisure battery.
You may need to review your battery charging arrangements for LiFePO4 compatability.

 

[Pausim]

@Wissel and @Gromett are going down the build your own route which seems to give a lot more bang for bucks (ah for £’s). Unfortunately my technical ability doesn’t stretch that far.

I am now using my new LiFePO4 system for the first time. Last night I noticed that my led spot lights were getting warm and one turned itself off. I was suspicious that they might not be liking the 14.6v charging rate the battery needs. I turned off the charger and everything returned to normal as the voltage dropped.

I am wondering if anyone knows of a voltage regulating device I can introduce into the supply side of the battery so that I can feed say 13v into the consuming devices, whilst maintaining higher voltages on the charging side. I have separated the charging and consuming circuits with their own fuses so in wiring terms I can see a way of doing this, I just can’t find a device to perform the task.

^{_{Subscribers  do not see these advertisements}}

 

[Gromett]

@Wissel and @Gromett are going down the build your own route which seems to give a lot more bang for bucks (ah for £’s). Unfortunately my technical ability doesn’t stretch that far.

I am now using my new LiFePO4 system for the first time. Last night I noticed that my led spot lights were getting warm and one turned itself off. I was suspicious that they might not be liking the 14.6v charging rate the battery needs. I turned off the charger and everything returned to normal as the voltage dropped.

I am wondering if anyone knows of a voltage regulating device I can introduce into the supply side of the battery so that I can feed say 13v into the consuming devices, whilst maintaining higher voltages on the charging side. I have separated the charging and consuming circuits with their own fuses so in wiring terms I can see a way of doing this, I just can’t find a device to perform the task.

That happens on normal flooded cells as well. My charger peaks at 14.6v on the current (temporary) flooded cell.

I was fed up of LED's burning out so about 5 years ago bought a 12v regulator. It can take anything from 9v to 30v and outputs a rock solid 12v. Haven't had to replace any LED's since then and has got rid of the flicker.

Unfortunately that regulator is no longer available. I just did a quick google and it is something similar to this one.
https://www.atenlighting.co.uk/inline-regulator.html

Although mine can handle 10 Amps output (120Watts)

 

[Gromett]

@Wissel and @Gromett are going down the build your own route which seems to give a lot more bang for bucks (ah for £’s). Unfortunately my technical ability doesn’t stretch that far.

I am foregoing a BMS because I believe the top balancing reduces the lifespan of the batteries. I will be bottom ballancing mine then setting the charge voltage well below what they can handle. This will be safer and extend the life span by a large amount at the cost of <5% of the capacity....

 

[Wissel]

@Wissel and @Gromett I am wondering if anyone knows of a voltage regulating device I can introduce into the supply side of the battery so that I can feed say 13v into the consuming devices, whilst maintaining higher voltages on the charging side.

Something like this would be fine for LED light:


It says 5a output, but personally wouldn't trust it for more than 2a. Fine for LED's, I have a couple of these.

You'll need to set the output voltage with a multimeter or similar, but once done it should be fit and forget.

I use another similar unit (little more powerful) to power a 19v monitor. Been perfect for 5 years.

^{_{Subscribers  do not see these advertisements}}

 

[Wissel]

I think I'm finally ready to install my LiFePO4 setup. This is what's going in for anyone interested:

This is a 400Ah Winston LiFeYPO4 battery bank (4 cell, 12v) with a 123Smart BMS.

The charger is a Votronic VBCS 60/40/430 which is a combined 60A B2B, 40 EHU and 430w MPPT. Besides having a lot of different settings for LiFePO4 batteries, it has a port that enables it to directly control the BMS without the need for a relay.

The 120A relay is a new product from 123 (not on the market yet but will be very soon). It's a duel relay (2 x 120A) that uses very little power. It's purpose is to cut power from the battery before damage. If my charger didn't have the enable port, one side could be used for this purpose.

Instead I'm using one of the relays for all 12v and the other for my inverter. This is a 1500w Ecedoa PSW model that any of you quick at maths will realise is capable of drawing far more than the 120A rating of the relay. I've spoken to 123 regarding this and they are confident it will be fine as the 120A rating is a constant one.

From the battery is an isolator and here the cable splits into two. The reason for this is the BMS has two current sensors, one for current in and one for out. With these in place the app can see exactly how much charge the system is getting and how much load is being used. It shows both of these figures, along with a state of charge between:

On the roof will be 4 x 100w panels, connected in parallel. These will be connected inside the van so I can easily test each panel with a multi-meter if I have any issues. It will also make it very easy to add Schottky diodes if needed (lot of conflicting advice about these online, so I've ordered some and will test what effect they have on shadowing. I suspect none, but want to know for sure).

On the 12v side I've gone with 3 x fuse boards connected to a distribution box to keep neat. The 3 boards will be in different parts of the van to save having lots of long wire runs.

I think that's about it. It's been quite a learning curve researching LiFePO4, but I'm glad I stuck with it as this system "should" suit our needs perfectly.

Going to fit the roof upgrades tomorrow as long as the weather is okay (Dometic PW4500 awning, MaxxFan Deluxe, clever little combined 4G, WiFi and GPS antenna and panels) and then fit the electrical system a few days later.

Just hope it all works out as planned

 

[Wissel]

At long last the LiFePO4 is going in

The area the cells go is now finished. It's padded to help with vibration and has the heating ducting running underneath to provide a little warmth in winter (LiFePO4 doesn't like freezing temps very much). Here is the area with part of the battery cage in place:

and here the cells are in their cage and the front brace is fitted. This area is solid as a rock:

The recess in the bottom board is for routing the cables up. A panel then protects the cables which then go through cable glands in another top panel:

The area to the left houses the main gas and water stuff, the area to the right a Propex heater.

Finally for now, I've started the wiring:

The vans main electrics are fixed to the top of the heater locker. Once finished the whole area will be accessed by lifting the wardrobe base which starts where the higher rear shelves are.

On the right at the moment is the fused distribution box which then feeds three separate fuse boards around the van. Behind that is a smart relay that is controlled via the BMS and behind that a cutoff switch.

All of the negatives are fitted, apart from the final connection to the battery.

Next job is to wire in the BMS, then wire up the charger and inverter which are under the drivers seat. Then hopefully it will all work

 

[Gromett]

Nice job. I know LiFePO4 batteries don't like the cold. But heat will also kill them faster than you realise.. I would be a bit cautious about that setup???

^{_{Subscribers  do not see these advertisements}}

 

[Robert Clark]

Nice job. I know LiFePO4 batteries don't like the cold. But heat will also kill them faster than you realise.. I would be a bit cautious about that setup???

What would you say is an optimal temperature range?

 

[Wissel]

Nice job. I know LiFePO4 batteries don't like the cold. But heat will also kill them faster than you realise.. I would be a bit cautious about that setup???

It's only the heating ducting running underneath and then there's a 12mm panel between the cells and the duct. It's just to take the edge off in winter so should be fine. Just wanted to keep the whole area at the same temp as the habitation area.

Although these cells are supposed to be fine down to about -20 from memory, due to the Y in their chemistry (LiFeYPO4 - Y is Yttrium which coats the cathode and allows lower temp charging. I won't be testing this )

Just be glad to get the thing running after all these months

 

[Wissel]

What would you say is an optimal temperature range?

I know on my cells the optimum surface temp of the cells is between 0 and 40 centigrade. This is for charging and discharging safely.

^{_{Subscribers  do not see these advertisements}}

 

[Pausim]

My Relion LiFePO4 specifies a discharge range of -20c to +60c and a charge range of 0c to +55c.

 

[Gromett]

I recall seeing a test on LiFePO4 cells where there was peak efficiency around the 17/18°C from memory. I will try to dig out the report.
There was a bell curve from memory with the peak in that range.. It also affected lifespan also from memory. I am not 100% certain so would need to look it up again.

 

[Gromett]

This pdf covers some of it. Can't find my notes for the other report.

I think discharge capacity fades below 0°C and lifespan is reduced over 40°C

So 20°C seems about optimal???

Broken Link Removed

^{_{Subscribers  do not see these advertisements}}