Puma Battery Queries

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Originally Posted by Zeros

Would it it be possible to have a 75ah lithium starter battery + 100ah fridge /accessories battery using a DC-DC charger/regulator? Would this negate the problem between the two types of batteries and be reliable for remote area travel?

Any advice much appreciated

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Hi Zeros, and if you compare that setup with how my systems works.


With the setup you are considering, you still need to separate the two batteries once the motor is off.


So you would have about 100Ah, if you can get the full 100Ah from that lithium battery. Some lithiums only provide about 80% of their total capacity before their BMS shuts down.


With one of my setups, using an Optima D34 55Ah Yellowtop, if you allowed the Optima to be discharged no lower than 20% Soc, you would have about 95Ah available.


If you discharged the optima to 0% SoC, which you can safely do with the Yellowtops, you would have about 105Ah available.


From a weight prospective, my setup would only add about 4KG over the lithium AUXILIARY BATTERY setup, but would be less than a 1/4 of the 2 x lithium setup.


While the lithium may give you a longer life span, you could replace 4 Optimas for the same price.


For in-vehicle use, at this stage, lithium battery setups are not cost effective.

In terms of safety lithium battery are as good as lead acid?

The discussion just reminds me of sumgsong note 7

Just note the battery is right under wife's ass in our defender

I believe the Samsung battery issue was caused by a lack of ventilation causing a heat build-up, isn't that right?

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Originally Posted by Beery

I've just got one of these from Deep Cycle Systems. 100ah and good for 1000cca. I've put it in a Thunder battery box for camping but thinking of chucking it in the 130 and giving it a go as the main battery.https://uploads.tapatalk-cdn.com/201...39250cfa9c.jpg

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$$$$$$$$$$$ I guess

For the doubters here, Tesla powered by the same technology, dont worry about explosions.
The LiFePO4 batteries are better than lead acid/AGM.....
Why?

1. Lighter
2. Hold charge longer
3. Quicker to charge
4. Last longer (lots more)

But they cost $$$$$$$$$$

I bought a couple of 115AH deep cell AGM batteries that I use for camping/fridges for about $700 that should last 7-10 years as long as I look after them properly, That gives me 115AH of useable power when wired up in series.
YES they are much heavier than the Lithium batteries But they are also much cheaper.
As a cranking and winching power source I am not sure that the lithium batteries will preform as well as the dual wet cells that I have fitted at the moment to my trucks.
Time will tell but as at the moment I have 3 x 4WD's ( which all run dual batteries) a van, a boat and my ARK power boxes which total 13 batteries in total to maintain So swapping them all over to lithium at the moment is a bit of a gamble because I haven't been convinced that the lithium alterative and the cost is worthwhile.

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Originally Posted by drivesafe

Hi Zeros, and if you compare that setup with how my systems works. With the setup you are considering, you still need to separate the two batteries once the motor is off. So you would have about 100Ah, if you can get the full 100Ah from that lithium battery. Some lithiums only provide about 80% of their total capacity before their BMS shuts down. With one of my setups, using an Optima D34 55Ah Yellowtop, if you allowed the Optima to be discharged no lower than 20% Soc, you would have about 95Ah available. If you discharged the optima to 0% SoC, which you can safely do with the Yellowtops, you would have about 105Ah available. From a weight prospective, my setup would only add about 4KG over the lithium AUXILIARY BATTERY setup, but would be less than a 1/4 of the 2 x lithium setup. While the lithium may give you a longer life span, you could replace 4 Optimas for the same price. For in-vehicle use, at this stage, lithium battery setups are not cost effective.

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Interesting to here that you use the Optima Batteries.... I did have 2 Optima batteries into the missus 4wd when it was our tourer (D34 bought in 2013 and a D27F bought in 2014). The D34 is still going BUT the D27F is suspect and I had it tested & found that its lost 50% of its CCA capacity. I also noticed that when I had it on my 25amp CTEK smart charger that after the charger said it was charged that I noticed a small battery acid around the negative Terminal. I wiped this away and took the battery off charge (battery never got hot). A few days later checked the battery again and notice more acid around the negative terminal. Made a few phone calls and received not helpful advice from people in the know.
After a few weeks I tried again to charge it via the CTEK charger but the Ctek through up an error code. This is when I got the battery tested and found out that it had lost almost 50% of it's cca rating. This battery is only about 4yrs old and has not had a hard life yet I would notice that every now and then that the missus' car just wasn't starting crisply and that's when I removed the battery to check it out.... From this experience, I wouldn't bother spending the $$ on these optima batteries again as they have given me no better life than the cheaper lead/acid batteries...

The battery on my 2014 Defender went flat the other day. It had been struggling a bit and died when it wasn’t driven for a week. Original one that came with the car.

Charged it up but was till a bit sluggish.

On advice if father in law I added some Epsom salts. Seems to have improved it.

Intersted to to see how long it still goes for!

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Originally Posted by Zeros

Thanks Beery, is this set up hard wired into your vehicle or via lighter socket? Do you have any concern about crossing two types of batteries / potential discharge?

On a side note, I’ve had the same battery box (Engel branded) for a few years now, but the brain in the box has gone haywire. The display jumps all over the place from saying the battery is fully charged to alarm and actually shutting down saying low battery! Very frustrating. ...could this be due to the battery failing or is it a fault in the box? The battery still takes and holds charge from solar panels, keeping fridge running over at least 4 days, despite the box saying the battery is empty!

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Hi Zeros

Im going to set the battery box up as a mobile/temporary auxiliary battery for camping, it'll just charge while in the vehicle from the cigarette lighter socket. The lighter socket is switched with ignition so no issue with draining the cranking battery. Then I've got a solar panel and regulator for charging while camped.

Hard to say what might be wrong with yours, could be as simple as a loose wire. Might be worth talking to Engel or even to Arkpak who apparently are the manufacturer.

Cheers
Tom

Quote:

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Originally Posted by drivesafe

Hi Zeros, and if you compare that setup with how my systems works.


With the setup you are considering, you still need to separate the two batteries once the motor is off.


So you would have about 100Ah, if you can get the full 100Ah from that lithium battery. Some lithiums only provide about 80% of their total capacity before their BMS shuts down.


With one of my setups, using an Optima D34 55Ah Yellowtop, if you allowed the Optima to be discharged no lower than 20% Soc, you would have about 95Ah available.


If you discharged the optima to 0% SoC, which you can safely do with the Yellowtops, you would have about 105Ah available.


From a weight prospective, my setup would only add about 4KG over the lithium AUXILIARY BATTERY setup, but would be less than a 1/4 of the 2 x lithium setup.


While the lithium may give you a longer life span, you could replace 4 Optimas for the same price.


For in-vehicle use, at this stage, lithium battery setups are not cost effective.

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As a comparison with the 100ah LifePO4 that I've got, the DCS lithium battery is claimed to be good for 2500 cycles to 100% DOD and still retain 80% of its rated capacity. Optima mention "300+" cycles but don't say what DOD that applies to. Based on that you'd need 8 Optima's at around $300 each to match the lifespan. $2,400 for lead vs $1,200 for lithium.
The SC80 isolator lets you use 50% of your cranking battery's capacity which is going to hammer its lifespan so need to factor in quite a few replacements of that as well.

My preference, especially if a long way from help, is to protect the cranking battery like my life depends on it (it kind of does). So to have a completely separated starting and auxiliary power source means you'd need at least twice the Ah capacity in lead batteries allowing for no more than 50% DOD to get a reasonable lifespan out of them. Thats 50+kg compared to 13kg. If you're keen to make them last as long as possible you could go up to ~75-80kg of lead. If you go for a good brand, say Trojan, you're now beyond the cost of the single lithium battery, way over in weight and still short on lifespan.

The battery that I've got does prefer to be kept away from heat i.e. out of the engine bay, but the lead batteries carry a bit of residual scrap value after you're done with them. So swings and roundabouts to a degree.

Quote:

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Originally Posted by Beery

Hi Zeros

Im going to set the battery box up as a mobile/temporary auxiliary battery for camping, it'll just charge while in the vehicle from the cigarette lighter socket. The lighter socket is switched with ignition so no issue with draining the cranking battery. Then I've got a solar panel and regulator for charging while camped.

Hard to say what might be wrong with yours, could be as simple as a loose wire. Might be worth talking to Engel or even to Arkpak who apparently are the manufacturer.

Cheers
Tom

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Hey Tom, yes that's exactly how I use mine. It's a simple solution as long as the the lighter socket connection is good! ...the Engel box monitor / display aside. Cheers I'll pull the box apart further, if no luck I'll give Arkpak a buzz.