coopec
N/A
Apart from cost, cycle times life and "discharge state" what are the advantages and disadvantages of each type?
Thanks in advance
Thanks in advance
LiFePO4 Lithium Battery Vs AGM for House Bank "Pros" and "Cons"
- Thread starter coopec
- Start date
geem
Well-Known Member
You will get lots of biased replies I suspect. First question. Where do you intend to cruise? What will be the typical water temperature and cabin temperature? The reason I ask is that one of the advantages of lithium is there cycle life is attractive. Theoretical number of cycles is far greater than good quality lead batteries. However, if you intend to cruise in waters that are routinely 28/30 degC with cabin temperature circa 30 or above you will struggle to keep your batteries cool. Even sat there not charging or discharging they will be at ambient temperature. Add in rapid discharge and charging if you intend to impose high loads from cooking etc and battery temperature will likely be an issue. High battery temperatures impact on life dramatically regardless of whether you choose lead or lithium. Battery life is rated at 25degC. At an average battery temperature of 35degC you half the life. At 45degC you half it again. If you are cruising a part of the world where this is reality then lithium starts to look less attractive. Cost Vs life comparisons need to be adjusted accordingly.
We generally cruise in the Tropics. In the Caribbean the water temperature is typically 28degC with an average cabin temperature of about 28degC in winter. More in the summer. Battery temperature can push over 30 degC even with good mechanical cooling. It's hard to keep battery temperature any lower without A/C in the battery box.
Our Trojan T105s cost $150 US each. We dropped our domestic bank from 1000Ah to 450Ah because heat was killing the batteries before we got near the design life cycles. Our domestic bank therefore cost us $600 US. Hard to beat on a value for money basis when comparing with lithium assuming high ambient temperatures where lithium will have a lower life expectancy. the initial cost of setting up for lithium is high compared to just staying with lead for us. We expect to get at least five years out of the Trojans.
I expect we will move over to lithium in the future. Cost of lithium drops about 7% annually. May be at the next battery replacement time we will make the jump of may be we will just spend another $600 US
We generally cruise in the Tropics. In the Caribbean the water temperature is typically 28degC with an average cabin temperature of about 28degC in winter. More in the summer. Battery temperature can push over 30 degC even with good mechanical cooling. It's hard to keep battery temperature any lower without A/C in the battery box.
Our Trojan T105s cost $150 US each. We dropped our domestic bank from 1000Ah to 450Ah because heat was killing the batteries before we got near the design life cycles. Our domestic bank therefore cost us $600 US. Hard to beat on a value for money basis when comparing with lithium assuming high ambient temperatures where lithium will have a lower life expectancy. the initial cost of setting up for lithium is high compared to just staying with lead for us. We expect to get at least five years out of the Trojans.
I expect we will move over to lithium in the future. Cost of lithium drops about 7% annually. May be at the next battery replacement time we will make the jump of may be we will just spend another $600 US
Kelpie
Well-Known Member
If you go the DIY route, lithium can come in cheaper than lead acid (especially expensive AGM).
I put together a 271Ah battery, basic cost was £407 for cells and BMS. Obviously there's more to it than that, e.g. panels, MPPTs, cables, fuses, inverter, etc. But most of that would have been the same regardless of battery choice.
By comparison a set of T105s to give same useable capacity would have been £690, plus the extras.
There are some compromises in my system. At the moment I can only charge from solar. I have nothing in place to handle disconnects- the power would just trip off. But I only have it powering the fridge and inverter anyway, not critical equipment. However these are far and away the largest loads (I cook electrically via the inverter) so there's little incentive to shift the other, smaller, loads (e.g. cabin lights) across to the lithium.
I put together a 271Ah battery, basic cost was £407 for cells and BMS. Obviously there's more to it than that, e.g. panels, MPPTs, cables, fuses, inverter, etc. But most of that would have been the same regardless of battery choice.
By comparison a set of T105s to give same useable capacity would have been £690, plus the extras.
There are some compromises in my system. At the moment I can only charge from solar. I have nothing in place to handle disconnects- the power would just trip off. But I only have it powering the fridge and inverter anyway, not critical equipment. However these are far and away the largest loads (I cook electrically via the inverter) so there's little incentive to shift the other, smaller, loads (e.g. cabin lights) across to the lithium.
geem
Well-Known Member
Useable capacity is an interesting subject. On 44 ft liveaboard boat where we cook with gas our typical overnight load at night is tiny. We run a fridge freezer and a separate fridge. Our 450Ah of Trojan batteries are always above 80% charged each morning. There is a lot of talk about taking batteries down to 50% but who actually does that as a liveaboard? I don't know anybody that does. We bought our Trojans in Puerto Rico where they were cheaper than the UK.
Poey50
Well-Known Member
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Good if lots of solar energy about but if using mechanical means to recharge it inevitably means going lower than 80% as charging from 80% via genny is an environment and cost (and noise) disaster. We plan to go down go down to 70% then back to 80% ish via genny then solar beyond that. Then plug in to shorepower for full recharge frequently. Cruising Scotland.
geem
Well-Known Member
I started reading the article and stopped when it said batteries sulphate because they only get charged to 80%. Yawn, mine and most others FULLY charge their lead batteries everyday.
Why can't these comparisons assume parity when doing these assessments. All of my friends running Trojans in the Caribbean get years out of them. 8 years is pretty typically. If you abuse lead you will reduce the life. Ditto lithium
geem
Well-Known Member
Solar is super cheap. It's not hard in the UK to fully charge with solar in the long summer days. We were cruising in July and August this year on South coast and we're using spare solar capacity once batteries were at float on sunny days to heat hot water.
PaulRainbow
Well-Known Member
I also have 450ah of T105s, mine almost never get below 80%, so i agree with all you said.
Poey50
Well-Known Member
I agree that seems unduly pessimistic. Of course many people do fail to get back regularly to full charge to avoid sulfation but that statement seems too sweeping. A pity to stop reading at that point as you miss a comprehensive set of disadvantages for LFP. Eric is no fan-boi.
For example ... "It is derisively easy to obtain a working system with a lithium battery bank on board – just put it in. It is unlikely to last any amount of time, it is unsafe and anything but clever. It is also a good way of eventually losing a significant amount of money. Many, many lithium house banks have been lost to specific and completely avoidable incidents so far. A number of others are in service with damaged cells, which is beyond questionable from a safety point of view."
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geem
Well-Known Member
Your right. It's a well balanced article. It reminds me to stick to lead for now. It works fine for us at the moment. It's cost effective and resilient in our installation. It would cost me too much in upfront costs to justify the change.
As an aside, people talk about cooking with electricity and lithium.
One thing to consider is how much cooking do you do. By comparison a friend said his gas bottle lasted three months. Ours of the same size only lasts a month! We are both liveaboards. My wife likes cooking. Bread, home made muisli, cakes, etc. We don't eat any pre prepared supermarket meals. We use fresh produce where possible. We use the oven a lot. If we were to cook electrically with lithium I can't imagine we could keep up with demand at times. In the Caribbean cooking gas is cheap.
Edit. Camping gas in UK was costing us £38 a pop in July. Calor dumpy was £18.
Here in Portugal we are paying €17.50 for Camping Gas. Significantly cheaper than UK.
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Agree with that. We’ve found solar production falls off sharply in the early/late seasons though when we’ve reverted to genny when necessary.
coopec
N/A
As geem suggested on another thread I should be looking at building up a bank myself. There are plenty of DIY videos on the subject.
building DIY lithium battery ban - Google Search
building DIY lithium battery ban - Google Search
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coopec
N/A
I've been working on urgent matters (small house renovations before visitors arrive) so I am just getting around to responding to comments on this thread.
Thank you for your comments: I always appreciate them.
I think I am going to follow your lead and use AGMs until they need replacing in 4/5 years then I'll think about Lithium. I hadn't considered battery temperatures so now I'm considering using the "load" output on the PWM to run a bilge blower which may circulate air in the bilges where the batteries are mounted (just below the floor). Battery temperatures are obviously something I'll have to watch. ?
Thank you for the heads-up
geem
Well-Known Member
Why AGM? Are you intending to install them upside down?
Good quality true deep cycle batteries such as Trojan T105s are better value, stand up to abuse better and are likely to last longer. If you can't get Trojan look at golf cart batteries from other manufacturers. Install the batteries lengthways across the boat so enure less uncovering of the lead when leaning over. I never see the advantage of AGM.
Poey50
Well-Known Member
One tip for those considering switching to LFP at a later date is to ensure that any new charging devices bought in the interim are fully and easily user-configurable so they can now be used on lead acid but ready for the change. For me this means Victron Bluetooth versions since it is so easy to change and store different settings and to update with new firmware. Avoid any charging devices that only have lithium settings - these are almost always too high. And you don't need to be messing with dip switches. Give yourself a year or two to research so you know that anything bought in advance will fit the final plan. So if the alternator goes and alternator charging of LFP is on the cards then it may be sensible to change up to something like a Balmar and external regulator. House bank fusing can be upgraded to T-Class. All will work happily with lead acid and LFP and also cushion the eventual financial hit.
sailaboutvic
Well-Known Member
Just one big advantage, you having got to worry bout getting them up to float ,
If at any time I am drawing 200a ( kettle , microwave and the hot water heater at the same time ) out of mine bank which I offen do the voltage never drop below 13.1v .
As for charging , as I wrote else where I hardly used my B2B so far this year the solar has kept then up .
If at any time I am drawing 200a ( kettle , microwave and the hot water heater at the same time ) out of mine bank which I offen do the voltage never drop below 13.1v .
As for charging , as I wrote else where I hardly used my B2B so far this year the solar has kept then up .
coopec
N/A
I'm all new to this. I thought AGM was better
But when I read this I am now confused
AGM batteries generally last longer than standard lead acid batteries. Because of their low self-discharge rate, AGM batteries also last longer than their flooded counterparts when not in use. A well-maintained AGM can last up to 7 years, while flooded batteries typically last around 3-5 years.6 July 2021
sailaboutvic
Well-Known Member
Robin , we just about to test that one out , so far it's been find , it's going to be interesting to see what happen over the next few month especially if it get really cold that we use the electri rad like we did the end of last year
Kelpie
Well-Known Member
Well yes AGM is better and lithium is better still.I'm all new to this. I thought AGM was better
But when I read this I am now confused
AGM batteries generally last longer than standard lead acid batteries. Because of their low self-discharge rate, AGM batteries also last longer than their flooded counterparts when not in use. A well-maintained AGM can last up to 7 years, while flooded batteries typically last around 3-5 years.6 July 2021
Deep cycle flooded lead acid is much cheaper than AGM though, and I don't think AGM necessarily wins in life cycle cost.
IMHO if you can afford AGM you can afford Lithium, depending on how many bells and whistles you want to incorporate.