Best use of spare LiFepo4 battery.

[pdid]

Hi, I recently upgraded my LiFepo4 battery to one with better BMS control.

Now I have a spare,100ah, LiFepo4 battery. I have a few ideas but I'm unsure of how it would work....

Firstly, Andersen parallel connection to extend leisure battery capacity. I was hoping I could just plug this in if the leisure battery got low but I believe this isn't the case....

Secondly charge the leisure battery with this battery? DC to DC? Not sure how it even if that would work?

Thirdly build a power station type thing. Is there anything available in kit form that doesn't cost the earth? I'd obviously like to keep it as cheap as possible. Don't mind a bit of diy if it comes in cheaper.

Fourthly sell it on, which doesn't really seem worth it for the money I'd get, plus issues with posting....

Thanks for any help

 

[Dellmassive]

Build a portable battery box....

And charge with a mains charger, like CTEk or Victron. (Don't parallel them)

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It -- It's about time that I got this long-overdue project sorted out. The missing parts are on order and completion is in sight . . . . . . . . ready for the Post Pandemic 2020 Camping Trips (Hopefully) This is where it started. p1...

www.t6forum.com

.

 

[pdid]

Build a portable battery box....

And charge with a mains charger, like CTEk or Victron. (Don't parallel them)

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It -- It's about time that I got this long-overdue project sorted out. The missing parts are on order and completion is in sight . . . . . . . . ready for the Post Pandemic 2020 Camping Trips (Hopefully) This is where it started. p1...

www.t6forum.com

.

Interesting thread thank you However, we're 4 years on from there, it's there anything you'd do differently? Anything come to market that makes building more straightforward?

I've only skinned through the thread so will have a proper read later.

 

[Dellmassive]

What battery have you got?

 

[Dellmassive]

V2 is much simpler.. as we start with a modern lifepo4 with a decent BMS, so a lot of the extras needed for the valance battery are ditched.


From Post#27

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --

@Dellmassive Got my panels connected to the Ctek with the BM2 monitor on the leisure battery. Is there a simple cheap monitor I can put inline on the solar panels to see what they are actually outputting ?

www.t6forum.com

.

But it's still worth reading from the start.

 

[pdid]

What battery have you got?

It's a DC House {Ecoworthy) 100Ah, so no onboard Bluetooth trickery, thanks.

 

[TallPaul_S]

Got a shed that needs some power to some basic electrics (lights, low power 240v stuff etc?)? There's a thread for that too on here!

Solar Sheds & Other Non-t6 Solar Projects - How We Done It -

There is definitely a north-south divide on this. The Northern DCC relies on long Wave radio signals operated by Arquiva. They have major signal congestion, hence the poor reception in rural northern areas.

www.t6forum.com

 

[roadtripper]

Firstly, Andersen parallel connection to extend leisure battery capacity. I was hoping I could just plug this in if the leisure battery got low but I believe this isn't the case....

Don't do this, LiFePo are not like "bare" lead acid cells they are BMS managed and they generally can only be banked with identical batteries with and only specifically how the vendor says is supported unless you want bad interactions between the BMSes.

I'd either build a basic portable battery box or power a shed - if doing the shed ensure the charge has a 0 degrees cutoff as those batteries do not and you don't want it going all hot air balloon on you like the image on another thread

 

[Sackmycook]

Shed solar +1.....
I have 3 batteries, 1 on solar charge, 1 running a string of lights on the shed via a 300w invertor and 1 charged spare. I rotate them every few weeks.
I can also charge my Jackery 500 from the battery on the inverter.

All freebies or bought cheap on the Forum or ebay

 

[JumpShip]

I need to get my head around all this solar stuff

 

[pdid]

Thanks again for the replies, I've no need for a shed system at the moment.

I'll have a look at the battery box but I'll more than likely sell it on if I can get reasonable money for it.

Thanks again.

 

[roadtripper]

I need to get my head around all this solar stuff

In the van or in the shed?

You can dip your toe in quite simply if you have a spare battery, just get a 100w ish panel when a sale is on (£80 ish) and a simple Victron MPPT (£40 ish) and some cable (£20 ish)

You can get cheaper basic MPPT but the Victron is not much more and is very configurable. For the shed scenario they generally have a "load" terminal that you can wire 12v garden lights to and have it control then directly.

 

[JumpShip]

In the van or in the shed ?

For the van .
Have got a AGM in at the mo but no method of charging other than plugging a charger into the mains .
Batt must be about 4 years old so I'm thinking a lithium battery upgrade and a flexi panel stuck to the roof ....but I really do know nothing about this or what is good and what is not .

 

[Stay Frosty]

For the van .
Have got a AGM in at the mo but no method of charging other than plugging a charger into the mains .
Batt must be about 4 years old so I'm thinking a lithium battery upgrade and a flexi panel stuck to the roof ....but I really do know nothing about this or what is good and what is not .

Factor in about a sub £2k spend for a decent hefty but basic set up and whether you need one or just want one.
We can manage from hook up most times in our camper as we're pansies and tend to camp on club sites but I wanted the option to survive more than two days off grid if we ever went to Busfest on a Thursday or any three day festival.

 

[TallPaul_S]

Factor in about a sub £2k spend for a decent hefty but basic set up and whether you need one or just want one.
We can manage from hook up most times in our camper as we're pansies and tend to camp on club sites but I wanted the option to survive more than two days off grid if we ever went to Busfest on a Thursday or any three day festival.

Yep, for instance for me I rarely use 'luxury' campsites with hookup etc, I prefer small/basic sites away from people, and free parkups, along with a decent amount of induction cooking, sometimes for several days at a time.

So, I need a big battery, big solar panel, and big alternator charging to keep up with my usage. That means a 230Ah LiFePO4 battery, 300w solar panel, 50a alternator charging, and a 2000w inverter.

 

[JumpShip]

Haemorrhaging money at the mo chasing an oil leak so will be starting small 100ah , simple charge system and maybe a 200w flexi is what I had in my mind

 

[ginkster]

Haemorrhaging money at the mo chasing an oil leak so will be starting small 100ah , simple charge system and maybe a 200w flexi is what I had in my mind

That’s what I’ve got. I don’t have an inverter and comfortably get 4+ days without any charging using lights, USB chargers, fridge and heater. The solar (a 200w Renogy flexible panel) makes the system everlasting in all but the worst prolonged period of weather. I hardly ever use the DC-DC and haven’t bothered fitting the mains charger as I don’t need to plug into EHU.

 

[JumpShip]

Sounds ideal have you documented what you've done in a build thread somewhere ?

 

[ginkster]

Not a single build thread, but posts in various leisure electrics threads and the ‘what have you done to your van today’ thread. Mine was an upgrade to lifepo4 plus solar which also meant replacing the existing, but unsuitable, CBE kit and taking the opportunity to relocate things from the rear wardrobe.

In short(ish), it was a rewire from SB to new Victron DC-DC, Fogstar 105ah battery, Victron shunt and Ablemail AMT12-2 under the passenger seat.



Cable then runs to the rear wardrobe to the original CBE fuse box to distribute the power to lights etc. The Victron MPPT and solar isolator is here as well as that was the easiest place to route cables from the panel. The panel is a Renogy 200w flexy that I have Sikaflexed to the pop top with a 5mm gap underneath. I put PPF on the roof first in case I ever need to replace the panel. Cables route via a Scanstrut gland through the pop top (outside the tent) then into the tailgate cable seal then to wardrobe.







I’ve also put cabling in for a Victron ip65 mains charger under the drivers seat (not much room as heater pipework is there) but never actually fitted it as I’ve not needed EHU since the upgrade. That was the whole point really, to be free of hookup.

If I was to do it again I’d use the Victron XS DC-DC as it runs a bit cooler but that wasn’t available when I bought my stuff. Let me know if you want to know anything more.

 

[JumpShip]

That's a massive help thanks Ginkster , I just need to make a shopping list now .
Maybe if was a good boy then santa would look after that but hey ho