Lithium LifePo4 12v Batteries - Time For An Upgrade?

[needsmust]

I've got a factory fitted leisure battery under the factory swivel base so the base seat battery looks really good as an upgrade, but is it as simple as just swapping them, and do I need to worry about leaving permanently in the van?

I've got a factory fitted leisure battery under the factory swivel base too (6.1 shuttle). I've not so much as touched it before but today a Dometic CDF11 cooler/freezer got delivered, which fits between the seats (just) and after a quick dash cigarette lighter socket play, I'm happy that it is an amazing bit of kit - which it needs to be to justify the £300.

So here's the noob question: How do I tap off the leisure battery? All I can see under the seat is all the wires I might have expected, but I suppose that I was actually expecting a dedicated outlet/ cigarette lighter affair. Not so much as a hint about the 2nd battery in the manual.

Sorry to sound like such a spanner, but how does it work?

 

[RoamerBatteries]

I've got a factory fitted leisure battery under the factory swivel base too (6.1 shuttle). I've not so much as touched it before but today a Dometic CDF11 cooler/freezer got delivered, which fits between the seats (just) and after a quick dash cigarette lighter socket play, I'm happy that it is an amazing bit of kit - which it needs to be to justify the £300.

So here's the noob question: How do I tap off the leisure battery? All I can see under the seat is all the wires I might have expected, but I suppose that I was actually expecting a dedicated outlet/ cigarette lighter affair. Not so much as a hint about the 2nd battery in the manual.

Sorry to sound like such a spanner, but how does it work?

The factory aux battery has a smart relay so that the alternator can charge both batteries when driving, but will isolate the starter battery when the engine is off. This means you can run the factory diesel heater until the aux battery is empty, but still be able to start the van and drive off.

You 'could' run a load off the aux battery either by using the terminal block (assuming this was fitted at the factory too) or by connecting directly to the battery terminals. I wouldn't advise doing this however as its only a 75Ah battery and you could kill it by running a constant load (like a fridge). Better to have a separate leisure battery for your campervan electrics.

 

[needsmust]

Thanks Steve,
Without a proper look, I don’t know if there’s a handy terminal block but I hope so.
It’s not a camper, and the little fridge is only 10.5 litres. It’s a compressor and can get down to -18 in minutes without too much drain.
We’ll just sling a tent up and aim to let it tick over on the 2nd battery, or just freeze some blocks for a separate cool box. Any actual fridge action at all will be a bonus for tenting. The fridge has battery protection cleverness, but I just want to be confident that the 2nd battery can run flat without the worry about starting the engine.
If I’ve understood correctly (and my hopes when choosing options are right) I can abuse the van’s juice with the engine off and all I’ll flatten is the leisure battery.
Much appreciated, cheers.

 

[Strettyp]

Thanks Steve,
Without a proper look, I don’t know if there’s a handy terminal block but I hope so.
It’s not a camper, and the little fridge is only 10.5 litres. It’s a compressor and can get down to -18 in minutes without too much drain.
We’ll just sling a tent up and aim to let it tick over on the 2nd battery, or just freeze some blocks for a separate cool box. Any actual fridge action at all will be a bonus for tenting. The fridge has battery protection cleverness, but I just want to be confident that the 2nd battery can run flat without the worry about starting the engine.
If I’ve understood correctly (and my hopes when choosing options are right) I can abuse the van’s juice with the engine off and all I’ll flatten is the leisure battery.
Much appreciated, cheers.

If it's a standard (i.e. non lithium) battery then you will kill the battery, I think they hit 50% charge then boil dry and you're looking at a dead battery

Someone will be along with a more technical explanation but that's what I've picked up off here

 

[t0mb0]

If it's a standard (i.e. non lithium) battery then you will kill the battery, I think they hit 50% charge then boil dry and you're looking at a dead battery

Someone will be along with a more technical explanation but that's what I've picked up off here

A modern AGM battery is rather more tolerant than that, touching 50% won't kill it! It's more like a progressive process, if you run it down to 50% regularly you'll get fewer cycles out of it than if you only ran it down to 80%. You need to try reasonably hard to actually kill the thing.

For what it's worth, I still have the factory fit 75Ah AGM 2nd battery in my four year old camper with the usual fridge etc and it's done me fine. Having said that I have a decent system to keep it topped up, a DC-DC charger and a 250w solar panel - haven't touched a hook up lead in a couple of years. A larger battery gives you more leeway when there's no charge going in, but in the long term, your ability to keep going off grid is determined by charge in vs charge out...

 

[t0mb0]

A modern AGM battery is rather more tolerant than that, touching 50% won't kill it! It's more like a progressive process, if you run it down to 50% regularly you'll get fewer cycles out of it than if you only ran it down to 80%. You need to try reasonably hard to actually kill the thing.

For what it's worth, I still have the factory fit 75Ah AGM 2nd battery in my four year old camper with the usual fridge etc and it's done me fine. Having said that I have a decent system to keep it topped up, a DC-DC charger and a 250w solar panel - haven't touched a hook up lead in a couple of years. A larger battery gives you more leeway when there's no charge going in, but in the long term, your ability to keep going off grid is determined by charge in vs charge out...

To give some more colour.... this 50% number is bandied around a lot on forums as some kind of absolute max DoD for AGM batteries but it's just not true. To give a concrete example, take a 130Ah Leoch leisure battery, which is a decent but not particularly special leisure AGM.

12V 130AH Leoch Adventurer AGM Leisure Battery (LAGM130) NCC Class A - Alpha Batteries

12V 130Ah fit-and-forget AGM lead-acid battery for leisure,marine & many other deep cycle applications – from Leoch’s Adventurer AGM range […]

www.alpha-batteries.co.uk

The manufacturer actually provides number of cycles as a function of DoD in the data sheet, which I've pasted below. You can see from this the progressive nature, if you extract 20% they estimate 3500+ cycles, at 50% you get to 1200ish and if you hammer it by extracting 80% every time you're down to 500 cycles.

Obviously, the use case is critical but, in my personal case, it's used on trips about ten weeks a year max, and during that time the solar and DC-DC charging means the average DoD is probably about 30% (I mean 30% extracted, not down to 30% SoC!) but I have the flexibility to run it down much further than that without worrying it's going to do anything terrible.

 

[needsmust]

That’s a bit of knowledge which backs up my experience.
I’m not planning to hammer the battery, but it won’t die by going flat. I’ve neglected enough batteries on bikes & boats over the years to know it will be ok. Whether I get 500 or 5000 cycles doesn’t really matter.
Thanks chaps.

 

[Jean-Louis Bourdon]

Hi Roamer,
very interested in the seatbase shaped battery, just a question: how do you secure it to the floor/seat. can you post a pict?

View attachment 109475

 

[RoamerBatteries]

Hi Roamer,
very interested in the seatbase shaped battery, just a question: how do you secure it to the floor/seat. can you post a pict?

We leave installations to the customer as everyone will have their own ideas on the best way to secure it. The new design is 4.5cm narrower than the one in this pic however, so will fit pretty snug between the rails of the seat base. All you therefore need to do is secure it front and back - there is plenty of space to add an L bracket or similar, which you can attach using self tappers or bolts through the floor.

 

[RoamerBatteries]

We just had a delivery of the seatbase batteries so took some quick pics and posted on this thread All of these have been sold on preorder but we have more coming next week - will be ready for despatch between 3-10th May.

 

[Dellmassive]

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RENOGY 12V 100AH SMART LITHIUM IRON PHOSPHATE BATTERY W/ SELF-HEATING FUNCTION​

DESCRIPTION​

The Renogy Smart Lithium Iron Phosphate Battery enables the auto-balancing among parallel connections and provides more flexibility for the battery bank configuration. The integrated battery management system (BMS) not only protects the battery from various abnormal conditions but monitors and manages the charging and discharging process. The state-of-the-art battery cells ensures an extended cycle life and exceptional discharge performance. With built-in intelligent self-heating, the battery is rechargeable even in low-temperature conditions. If you’re searching for a deep cycle battery for caravan, cabin, or marine use, then this lightweight, auto-balanced, ultra-safe, long-cycle-life lithium battery is the perfect plug-and-play solution for you!

The Rover charge controller are fully compatible with this battery. If you have any questions regarding this product, please submit a case..

NOTE:
● The normal operation of the self-heating function requires a stable charge current greater than 4A for each battery in the parallel battery bank. The self-heating function will not be able to operate normally if a PWM charge controller or a small current battery charger is used to charge the battery at low temperatures.
● Please secure all cable connections to the proper specification in order to ensure good contact between the cable lugs and the terminals. Over-tightening cable connections can cause terminal breakage and loose cable connections can cause terminal meltdown or fire.
● DO NOT string the battery in series. ONLY connect batteries of the same manufacturer and model in parallel.
● Please avoid too high a voltage difference between paralleled batteries, despite the auto-balancing function, to avoid triggering the over-current protection.

Auto-Balance

• Connects multiple batteries in parallel safely with the auto-balancing function to meet the power and energy requirements of different system setups.

Ultra-Safety

• The battery management system (BMS) provides comprehensive protection to the battery and manages the charging and discharging process.

Uncompromised Quality

• The state-of-the-art battery cells ensure an exceptional lifespan of more than 4000 cycles (80% DOD), up to 100A continuous discharge current, and a wide range of operating temperatures.

Communication Port

• The communication ports enable the communication between connected batteries, external devices, and host computers.

Self-Heating

• The intelligent self-heating feature keeps the battery charged in cold environments.

SPECIFICATIONS
Rated Capacity: 100Ah	Insulation Resistance: 500V DC, ≥ 10 MΩ
Operating Charge Temperature: 32~131°F/ 0~55°C	Maximum Continuous Charging Current: 50 A
Operating Discharge Temperature: -4~140°F/ -20~60°C	Maximum Continuous Discharging Current: 100 A
Voltage Range: 10~14.8 V	Communication Port: RJ45 (RS485 Protocol)
Nominal Voltage: 12.8V	Storage Temperature: -13~149°F/ -25~65°C
Connection Method: Parallel	Cycle Life (0.2C, 25℃): ≥4000 Cycles @ 80% DoD
Dimensions:11.4 x 6.8 x 7.4 inch / 289 x 172 x 187.5 mm	Weight: 26.2 lbs. / 11.9 kg
Certifications: UN38.3, MSDS, UL1642 (Lithium Cell)
Protection Rate: IP54

WARRANTY INFORMATION​

Accessories

5-year prorated warranty

 

[mrdanielmh]

Hey folks, looking for a 100ah Lifepo4, wondering what everyones recommendations are? I had previously done a DIY with cells, but the BMS just died and I need to go away next week!

I see the Renogy 100ah is 629, but the Infinity powerroad is around the same price.

Any recommendations, thoughts?

 

[DXX]

If you’re going away next week I guess it will come down to availability / delivery.
@Dellmassive will have a good view when it comes to batteries, careful he doesn’t recommend you get two of each!

 

[JBR80]

Hey folks, looking for a 100ah Lifepo4, wondering what everyones recommendations are? I had previously done a DIY with cells, but the BMS just died and I need to go away next week!

I see the Renogy 100ah is 629, but the Infinity powerroad is around the same price.

Any recommendations, thoughts?

I bought a remanufactured Sterling power 100ah for £450, but even their full price is £540. I haven't used it yet, so I can't report performance but Stirling power are a solid company, the battery has good specs.

 

[DXX]

Having a self heating function is obviously good to maintain charging capability in freezing conditions but it also draws power.
There are long discussions on the Forum regarding battery protection (temp and voltage), if you’re not careful the van cabinets can end up looking like a sub-station and there’s nowhere left to put your belongings.
Keep it simple would be my advice.

 

[mrdanielmh]

I bought a remanufactured Stirling power 100ah for £450, but even their full price is £540. I haven't used it yet, so I can't report performance but Stirling power are a solid company, the battery has good specs.

Thanks! Let me know any feedback you might have. I have to go away in the van on Thursday and currently have no battery Does the app allow BMS modifications?

 

[mrdanielmh]

Having a self heating function is obviously good to maintain charging capability in freezing conditions but it also draws power.
There are long discussions on the Forum regarding battery protection (temp and voltage), if you’re not careful the van cabinets can end up looking like a sub-station and there’s nowhere left to put your belongings.
Keep it simple would be my advice.

Haha thank you! I've already got the sub-station effect! Trying to simplify everything right now!

 

[mrdanielmh]

Thanks! Let me know any feedback you might have. I have to go away in the van on Thursday and currently have no battery Does the app allow BMS modifications?

Doesn't look like it has a low temperature cutoff? Might be wrong though

 

[JBR80]

Doesn't look like it has a low temperature cutoff? Might be wrong though

I'm not sure on the full BMS specs, but it does cutoff charging at 0C and allow it again at 5C, it also shuts off use at -20C and allows it again at -15C. This is not in the specs but was confirmed in writing by Ben @ Stirling Power

 

[JBR80]

Thanks! Let me know any feedback you might have. I have to go away in the van on Thursday and currently have no battery Does the app allow BMS modifications?

I have not connected smart BMS to the battery yet, so I'm not sure on the capabilities. Ben at Sterling power is very knowledgeable and helpful, if you have specific functionality questions.