pvb
Well-Known Member
A couple of people have suggested Tayna, but they don't sell Hankook batteries. Is the Hankook XL31 more or less exclusive to Battery Megastore?
AGM vs deep cycle
- Thread starter pessimist
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wipe_out
Well-Known Member
Doesn't look to me like the question has been fully answered.. The post is titled "AGM vs Deep Cycle" which is a mix of battery type vs battery use case..
There are pros and cons to AGM vs Lead Acid/Sealed Lead Acid and depending on what its being used for will determine if deep cycle is needed or not..
In simple terms the only time deep cycle is NOT needed is for the engine starter batteries, pretty much all other uses on a boat need a deep cycle battery..
The choice of AGM vs SLA/LA is more complicated.. Disadvantages to AGM are the up front cost but in general the advantages are no gassing, no leaking, mounting in any orientation, faster charging and higher number discharge cycles..
Disadvantages of LA are things like when the boat heels it can expose the lead plates as the acid sloshes around, potential of leaking acid, gassing but the advantage is they are generally cheaper..
Largely it comes down to your application, installation location, usage and budget..
For us we felt AGM deep cycle for the house bank was a no brainier..
There are pros and cons to AGM vs Lead Acid/Sealed Lead Acid and depending on what its being used for will determine if deep cycle is needed or not..
In simple terms the only time deep cycle is NOT needed is for the engine starter batteries, pretty much all other uses on a boat need a deep cycle battery..
The choice of AGM vs SLA/LA is more complicated.. Disadvantages to AGM are the up front cost but in general the advantages are no gassing, no leaking, mounting in any orientation, faster charging and higher number discharge cycles..
Disadvantages of LA are things like when the boat heels it can expose the lead plates as the acid sloshes around, potential of leaking acid, gassing but the advantage is they are generally cheaper..
Largely it comes down to your application, installation location, usage and budget..
For us we felt AGM deep cycle for the house bank was a no brainier..
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geem
Well-Known Member
Doesn't look to me like the question has been fully answered.. The post is titled "AGM vs Deep Cycle" which is a mix of battery type vs battery use case..
There are pros and cons to AGM vs Lead Acid/Sealed Lead Acid and depending on what its being used for will determine if deep cycle is needed or not..
In simple terms the only time deep cycle is NOT needed is for the engine starter batteries, pretty much all other uses on a boat need a deep cycle battery..
The choice of AGM vs SLA/LA is more complicated.. Disadvantages to AGM are the up front cost but in general the advantages are no gassing, no leaking, mounting in any orientation, faster charging and higher number discharge cycles..
Disadvantages of LA are things like when the boat heels it can expose the lead plates as the acid sloshes around, potential of leaking acid, gassing but the advantage is they are generally cheaper..
Largely it comes down to your application, installation location, usage and budget..
For us we felt AGM deep cycle for the house bank was a no brainier..
I don't get the exaggerated claims for AGM. Taking two reputable battery manufacturers I looked at the lifecycle charts published for the Trojan T105s and the Lifeline deep cycle AGM. They are easy to find on the internet. So at a 20% DOD the lifelines predict 2750 cycles. The Trojans say 4000 cycles. At 30% DOD lifeline say 1750 cycles, Trojan say 2750. I dont like the idea of paying more for AGMs just so I can mount them on their side. I have an acid proof battery box with a ventilation system. The lead antinomy batteries have a higher self discharge rate than AGM but who doesnt have solar these days to deal with that. I see no need for AGMs at inflated prices with less life expectancy. Other manufacturers batteries might predict better life expectancy but Lifeline are well respected but in a simple comparison they wont last as long as T105s assuming the water is topped up. Am I missing something? Also cost. A Lifeline 210 amp hr AGM costs £750 from Tanja. Two T105s giving more amp hrs cost £300. Anybody want to do a comparison where AGM come out on top for battery life and cost?
Bobc
Well-Known Member
You can lead a horse to water......
wipe_out
Well-Known Member
As I said it comes down to your application, installation location, usage and budget.. Our batteries are all inside the saloon of a sailboat under the seat.. Battery boxes would have reduced the number of batteries (capacity) we could have or we would loose more storage space which is always at a premium.. The idea of the gas inside wasn't appealing and exposing the plates while heeling isn't great.. Then zero maintenance was appealing too, checking and topping up water would just add another regular job that isn't necessary..
I agree that lifeline batteries are reputable but they are also insanely expensive.. We used the 2 x Leoch LAGM-130 (130Ah) for our house bank which claim 3000 cycles at 25% DOD And are currently £170 delivered from Alpha Batteries.. Time will tell how they work out in the long run..
geem
Well-Known Member
Thats a very small house bank. If you are running a fridge then I would expect your DOD to be a little more. What do you mean about battery box? Why do you think you need several? My single battery box is also under the saloon seats it holds four 250 amp hr house batteries and two starter batteries. Its a single box with sealable 10mm perspex lids. It also has a mechanical ventilation system. In my experience the battery water is easy to top up. They need it every few months not every week. I check the batteries monthly. The water level in the batteries more than compensates for angle of dangleAs I said it comes down to your application, installation location, usage and budget.. Our batteries are all inside the saloon of a sailboat under the seat.. Battery boxes would have reduced the number of batteries (capacity) we could have or we would loose more storage space which is always at a premium.. The idea of the gas inside wasn't appealing and exposing the plates while heeling isn't great.. Then zero maintenance was appealing too, checking and topping up water would just add another regular job that isn't necessary..
I agree that lifeline batteries are reputable but they are also insanely expensive.. We used the 2 x Leoch LAGM-130 (130Ah) for our house bank which claim 3000 cycles at 25% DOD And are currently £170 delivered from Alpha Batteries.. Time will tell how they work out in the long run..
geem
Well-Known Member
Q
A quick look at your batteries on the internet and it would appear they are in fact only 116 am hr at the c20 rating. They also only give 600 cycles at 50% DOD. For the similar money you could have two Trojans and get far more cycles and similar AhsAs I said it comes down to your application, installation location, usage and budget.. Our batteries are all inside the saloon of a sailboat under the seat.. Battery boxes would have reduced the number of batteries (capacity) we could have or we would loose more storage space which is always at a premium.. The idea of the gas inside wasn't appealing and exposing the plates while heeling isn't great.. Then zero maintenance was appealing too, checking and topping up water would just add another regular job that isn't necessary..
I agree that lifeline batteries are reputable but they are also insanely expensive.. We used the 2 x Leoch LAGM-130 (130Ah) for our house bank which claim 3000 cycles at 25% DOD And are currently £170 delivered from Alpha Batteries.. Time will tell how they work out in the long run..
Tim Good
Well-Known Member
Same here but got T105s.
JumbleDuck
Well-Known Member
Someone at the Boat Show was selling 68Ah Li-ion batteries from a reputable maker (can't remember who) for a mere £600. Since that's the same effective capacity as 120Ah of lead, at around 1/5 of the weight and good - they say - for 3,000 cycles, I'm almost tempted. Not quite, bit when something similar is £300, I'm buying.
Kelpie
Well-Known Member
I looked into this this and found that if you just go by the published numbers, deep cycle FLA are the cheapest option buy number of cycles. Lithium is a wee bit behind, with cheap 'leisure' batteries by far the most expensive. Being rated for only 250 cycles, or less, means they just can't compete, even if they are a quarter of the initial cost.
What is much harder to factor in is when you diverge from the expected usage pattern. Some people advocate buying a huge bank of cheap batteries and never taking it below 80% SOC. It can be hard to find manufacturers' numbers to suit this usage, especially with cheap batteries.
Lithium is becoming very tempting now, with some unique advantages (efficiency of charging in particular) but you need a BMS and there is always the risk that a faulty charging system could kill the whole bank. This doesn't matter so much with lead acid, but a viable lithium bank will cost thousands and need to last for many years to make economic sense.
What is much harder to factor in is when you diverge from the expected usage pattern. Some people advocate buying a huge bank of cheap batteries and never taking it below 80% SOC. It can be hard to find manufacturers' numbers to suit this usage, especially with cheap batteries.
Lithium is becoming very tempting now, with some unique advantages (efficiency of charging in particular) but you need a BMS and there is always the risk that a faulty charging system could kill the whole bank. This doesn't matter so much with lead acid, but a viable lithium bank will cost thousands and need to last for many years to make economic sense.
geem
Well-Known Member
I have been doing a lot of research on lithium. From what I can see lithium as a drop in replacement isnt there yet. Victron and Mastervolt can do it but at great expense. The technology is way different to lead acid and far more complicated than you can imagine. If there is a cheap lithium option then from what I have researched, you are very likely wasting your money. There are safety features necessary to operate lithium on a boat. Charging regimes need to be totally different to lead acid. For now we will stick with lead acid. May be by the time I need new batteries the market and supply chain will have moved on.
If you want to read about lithium on a boat this is a good place to start https://marinehowto.com/lifepo4-batteries-on-boats/
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PeterBoater
Well-Known Member
If these batteries are one-fifth of the weight then perhaps boat stability becomes a factor. I have nearly 200kg of AGM batteries in the lowest part of the bilge, almost in the keel; presumably replacing them with much lighter batteries would necessitate adding some other form of ballast.
geem
Well-Known Member
Only if the designer of your boat designed it with 200kg of batteries sat on top of keel. I have even heavier batteries but they dont form part of my ballast
Kelpie
Well-Known Member
Everybody knows about the weight and space advantages of Lithium, but a lesser known advantage, perhaps of more interest to yachties, is the charging efficiency.
Lead Acid batteries are very hard to fully charge. The first 80% or so will go in quite quickly, but the last bit takes longer and longer- indeed without a clever charging system you are unlikely to ever reach 100%, which not only gives you a smaller effective bank, but also somewhat shortens the lifespan of the batteries.
Secondly, throughout the charging process, lead-acid is quite wasteful as maybe half of the power you are throwing at them does not actually go in. And this effect gets worse as the batteries approach 100% SOC. This means that charging takes longer, and takes more power, so you need bigger solar panels.
I think lead-acid still wins for most boats, but Lithium has the upper hand where you have high power usage and limited space for solar.
Lead Acid batteries are very hard to fully charge. The first 80% or so will go in quite quickly, but the last bit takes longer and longer- indeed without a clever charging system you are unlikely to ever reach 100%, which not only gives you a smaller effective bank, but also somewhat shortens the lifespan of the batteries.
Secondly, throughout the charging process, lead-acid is quite wasteful as maybe half of the power you are throwing at them does not actually go in. And this effect gets worse as the batteries approach 100% SOC. This means that charging takes longer, and takes more power, so you need bigger solar panels.
I think lead-acid still wins for most boats, but Lithium has the upper hand where you have high power usage and limited space for solar.
PaulRainbow
Well-Known Member
Nothing actually gets wasted, the full potential of your charging source may not get utilised though.
No good fitting more solar in this case, if the batteries will only take xx amps, that's all they'll take, you can connect them to as many solar panels as you want, still won't get any more into the batteries.
pvb
Well-Known Member
That's very pessimistic. Most flooded lead-acid batteries have an efficiency of 75-80%, and AGM/Gel batteries can have an efficiency of 85-90%.
Mistroma
Well-Known Member
I suspect that he was referring to the losses production of unwanted heat and hygrogen. As you already know, a 100Ah at 50% will not be charged to 100% if you supply 50A for an hour (or 5A for 10 hours). There is certainly loss but the magnitude is determined by many factors (e.g. ambient temp., current supplied, battery chemistry, etc.).
You are of course correct about the futility of installing charge sources with very high output, beyond capacity of the batteries to accept. Well worth mentioning as well but it can be beneficial to have an excess in mid-summer and adequate supply in April or October.
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dom
Well-Known Member
A couple of months back I did a quick cost/performance analysis of U.K. batts most suitable for moderate to heavy domestic use, albeit seasonal in my case. The spectrum included el cheapo leisure up to top range AGMs and lithium. Lithium will almost certainly be the future default choice, but right now T105s seem to be the clear winner. I’d even say no brainier, space and weight considerations aside.
geem
Well-Known Member
Totally agree. I came to the same conclusion.
lw395
Well-Known Member
I'm pretty sure that's true for a heavily used boat or live-aboard, not sure it's true for a typical yacht which gets used for a couple of dozen day sails, a few long weekends and a three-week cruise each year. Or those which seem to be either in the marina or running the engine 80% of the time that people are aboard.
There are a lot of variables.