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Lead acid or Lithium, which battery?

Discussion in 'Camping Australia' started by T1 Terry, Nov 27, 2021.

  1. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Best get a coffee and a comfy chair where you can't fall out and hurt yourself when your eyes roll back in your head :lol:

    First I'll tackle what a lead acid battery and try to explain the different types that come under the same banner.

    The first is the flooded cell, we all know this one, it's similar to what is generally used as a start battery, you can unscrew the caps and top it up with distilled water ... yeah, like you didn't use the water out of the tap and the batter still lasted for yrs :rolleyes: The electrolyte in these batteries is a mix of sulphuric acid and water, the water gets split into hydrogen and oxygen when charging and discharging, but the most gassing activity is seen close to fully charged or when running an equalising charge. The flooded cell is battery is the only one that can handle an equalising charge, the electrolyte boils like a witches pot and uses up quite a bit of water while it's doing it. These are the batteries that can be tested with a hydrometer and the equalising charge is to get the specific gravity of the acid the same in each cell .... basically, the float thing shows the same numbers at the point where the liquid level on the float is the same. If the float doesn't float, it's measuring water not a sulphuric acid mix.
    If you have these type batteries as deep cycle batteries, you need lots of ventilation around the batteries, the area will need to be coated in paint and the battery kept well away from any sparks. If you don't need to regularly top up the electrolyte, you aren't fully charging the battery.

    I'll cover AGM batteries tomorrow so I don't make each post too long

    T1 Terry
     
  2. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Tomorrow took a bit longer, this attack of shingles is really hanging in there and taking it out of me, well either the shingles or the prescribed drugs ......

    AGM or Absorbed Glass Mat variant of the lead acid battery family.
    These cells are constructed with a fibreglass mat between each cell plate to hold the sulphuric acid solution from slopping around and requires less electrolyte. The technology also uses a "recombiner" in the top of the cell that is basically a catalyst that reacts with the hydrogen and oxygen produced in the cell and turns it back into pure water and this drips back into the electrolyte.
    There are 2 basic types of this battery, the US variant and the European variant.

    The US variant should have its "absorption" voltage limited to 14.4v until the charging current drops to ..... the formula varies between manufacturers .... but a steady 1.5 amps per 100Ah capacity seems to be a generally close enough rough rule, it the current flow (amps) hasn't change over a 3 hr period, the battery or cell is considered to be fully charged. At that point the voltage can be dropped to a holding level of 13.8v. Maintenance voltage, where the battery sits of a charger between uses is considered to be 13.6v, as long as the bulk charge, absorption charge and float charge regime is repeated every 30 to 60 days.

    The European variant is very similar, only the absorption voltage is 14.8v rather than 14.4v. The reason, this variant has better "recombiners" so they can handle a lot more gassing and actually reach the "fully charged" state quicker than the US variant.
    The difference between fully charged and saturation charged, the condition all the test specs are based on, requires the float voltage of 13.8v to be maintained for at least 24 hrs.

    Next one I'll tackle is the Gel variant, note, this variant is not really suited to RV use because it has very tight limits regarding the charging and discharging currents.

    T1 Terry
     
  3. njg02

    njg02 Active Member

    Messages:
    128
    Location:
    Rockhampton CQ
    Thanks Terry. Waiting patiently for you to tell me that there is a drop in lithium that I can use with my VSR.
     
  4. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Only another 2 types of lead acid batteries to go, then I'll get into the lithium batteries, then do a pros and cons of each type ...... Well, as long as the readers haven't all dropped off to sleep by then :lol:

    I get a laugh every time I watch the informal training class put on by Jay Whitacre at the Carnegie Melon University for the early EV builders .... part way through the camera scans across the group and there isn't one of them that have suffered the eyes rolling back in the head :lol: It helps me every time I see the same sort of thing happening when I do an hr long talk at any of the RV get togethers, I had to watch the Jay Whitacre talk 5 times before I reckon I followed all he was saying ...... and you can see he was trying desperately to dumb it down but every time he'd get on a subsection, away he went :lol:

    T1 Terry
     
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  5. David H

    David H Well-Known Member

    Messages:
    6,689
    Location:
    newcastle
    Watching & not asleep yet;).
    Lead acid start & deep cell LHS with a relay that separates both when ignition off.o_O
    All interior is from a 2nd fuse panel that the deep cell LHS powers.
    Fridge by gas.
    Am I on the right track for week long camping?
    Cheers
     
  6. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Do yo have a method of charging the battery other than the alternator/generator when the engine is running?
    I'll cover all that in the other thread so each becomes a sort of reference that hopefully will help decide just which system suits best for the use intended.

    T1 Terry
     
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  7. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    The Gel variant of the lead acid battery.
    These batteries are built with the electrolyte converted to a gel format ... the only benefit I can see is they can be mounted in different ways like on their end or on their side because the electrolyte won't leak out.
    These batteries require a very strict max charging current and voltage as well as a strict max discharging current and end voltage. This is required to stop gas bubbles forming on the plates and in the gel, because this starves that bit of the plate from contact with the electrolyte. Over time this results in sulphation on that spot and loss of capacity. That means the rest of the plate/electrolyte area is put under even more strain and a failure cascade event starts. These batteries were designed for UPS systems (Uninterruptible Power Supply) where the discharge and recharge are under a strictly controlled regime. The electrolyte can never be topped up and just one abuse event leads to total failure.
    These variants of the lead acid battery are not suited to RV house use.

    T1 Terry
     
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  8. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Last one on the lead acid platform, the lead crystal variant.

    These are a the latest variant, entered the market place with a lot of hype and fanfare, but don't live up to the hype. The problem is what isn't mentioned in the blurb that comes with the sales pitch. Yes, they can be discharged to 0% SOC and recharged to 100% SOC, the part they don't mention is all the steps required to recharge them from any level of discharge. They need to be recharged till the current flow drops off, the same as any other lead acid variant, but then they need to be discharged to 0% SOC, then recharged and this cycle continued until the 100% capacity returns .... then they are ready for the next use ......
    Unless you are prepared to baby sit your battery, these are not for you.

    T1 Terry
     
  9. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Should I do the pros and cons of this chemistry battery before moving on to all the various forms of lithium battery?

    T1 Terry
     
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  10. Wattie

    Wattie Well-Known Member

    Messages:
    1,309
    Location:
    Mildura. Victoria. Australia.
    Yes please.
     
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  11. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    OK, I'll try to do it by variant in the hope I don't add confusion.

    Flooded cell:
    Advantages - Can be topped up regularly and sort of easy to test for a bad cell using a hydrometer.

    Can handle over voltage charging the best of all the lead acid variants.

    Easy to see when it's getting close to fully charged by the rate of bubbles in each cell.

    Easy to see when a cell is in need of attention, it doesn't bubble as much or not at all when the other cells are bubbling away at a rapid rate. This generally indicates an equalising charge is needed.

    Down sides - Needs to be in a well ventilated area

    Need the electrolyte topped up regularly and the terminals cleaned along with the top of the battery.

    Needs a good coating of rubber paint over any metal in the area to avoid the acid fumes eating it away.

    Not a good idea to mount these under the bed or anywhere inside the living area due to the explosive nature of the gases produced.

    AGM:
    Advantages - If the charging regime is good, virtually no venting of gasses, but if there is a vent tube, feed it outside where it is not likely to be near any sparks or naked flames.

    If there is a vent hose in the battery that can be vented outside, they can be mounted within the living area.

    Generally don't require the build up around the terminals cleaned or the top of the battery, but still good to regularly wipe over to stop dust/dirt build up that if wet, will short out the battery between the terminals

    Does not require regular attention as far as topping up the electrolyte.

    Downsides - No way of knowing if a cell needs attention until it fails, then the whole battery must be replaced

    Can not be equalisation charged ... unless you sit there with the battery and regularly feel the sides to make sure it doesn't get hot and stop as soon as it does start to heat up

    Can not be left of a maintenance charge for long periods because the recombiners will add pure water to
    the top of the cell while the acid in the bottom gets more and more concentrated and actually starts to eat
    the plates away.

    Gel:
    Up sides - can be mount on the side or end.

    requires very little maintenance

    Down sides - requires a very strict charging and discharging regime. No tolerance for discharging too fast or charging
    too fast. This virtually eliminated solar charging unless the charging amps can be limited by the solar
    controller. the same goes for alternator charging and DC to DC charging, again, unless the charging
    current can be adjusted within the controllers

    Lead Crystal:

    Forget it unless you have a heap of time to baby sit them, their downsides I mentioned in the posts above.

    "Magic eye" type batteries that show a different colour if the battery needs water or needs charging are just fancy flooded cell batteries. "Sealed" batteries are not always AGM batteries, they could just be flooded cell batteries with a sticker over the caps.

    T1 Terry
     
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  12. KombiFringe

    KombiFringe Member

    Messages:
    156
    Location:
    melbourne
    Hi T1 Terry, thankyou for all that information on batteries. I’m buying some for my next trip and and still I’m a bit bewildered, as they all have drawbacks of course I was thinking lithium was my gold standard so now I’m reconsidering as I need 1/2 under my rear seat because I haven’t been kind to my batteries over the years they don’t last that long. I’m not rushing out to buy them just yet, On this 1/2 lap I want better batteries cause our club , Cmca, Solos network is going bush for 8 days. I have an Anderson plug on the back of my t2 for solar charging. looking forward to any other information you post.
     
  13. Squalo

    Squalo Active Member

    Messages:
    220
    Location:
    Sunshine Coast QLD
    Hi Terry, thanks for such great information.

    I have a 4 year old 110AH lead crystal battery that probably need the attention you mention above.

    It's certainly a performer, I once forgot to turn my fridge off when I left my Patrol parked for 7 or 8 days - empty 60 litre ARB Elements, solar panel not connected - and the battery did the job, fridge still running cold with battery down to around 7 volts.

    Can you do a quick post on how to properly bring a lead crystal back up to 100% when you have the time? Thanks : )
     
  14. KombiFringe

    KombiFringe Member

    Messages:
    156
    Location:
    melbourne
    Hi Squalo, Can you tell me what brand of battery please. Thamks
     
  15. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    Here is a video that will give you a starting platform, at around the 3.30 mark and around 7 min mark is where the important stuff it. They mention they will operate at a partly charged state, what isn't said is that until you do that deep discharge and long recharge, that partially charged state will continue to drop lower and lower, even though the volt meter says you have reached the 14.4v mark.
    That deep discharge down to well below 10v, then that long charging process till the 3 hrs @ 13.6v results in the charge current dropping back below 1 amp to maintain that 13.6v.
    To get closer to the 100% capacity, look to see what the "C" rating is on your battery, and connect a load equal to the C rating, C20 for a 100Ah battery is 5 amps, 100 / 20, C10 rate is 100 / 10 = 10 amps etc. Check the battery voltage under load at around half way through the test, 10 hr mark for a C20 rated and 5 hrs for a C10 rated battery. You are looking for better than 12v while still under load, check thevoltage again at 3/4 time to make sure it is above the minimum discharge voltage, then again 30 mins later to see if it's holding or actually running out of capacity early. You are looking to get the full 20 hrs or 10 hrs depending on the battery, without the voltage dropping below the manufacturers minimum voltage.
    If yo don't get it, do the whole recharge cycle again and then repeat the load test. It could take two or three cycles to get the capacity back, but if you don't do it, you risk the lost capacity becoming a permanent thing and any losses compounding from on top till the battery becomes a door stop or a paper weight.

    T1 Terry
     
  16. KombiFringe

    KombiFringe Member

    Messages:
    156
    Location:
    melbourne
    Thanks Terry I’ll give that a go .
     
  17. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    OK, here goes the eye rolling steep learning part.
    Honest lithium house battery manufacturers don't hide behind this 80% nonsense that someone started, based on not understanding what the Chinese specs actually meant.
    There is no mention from any of the actual cell manufacturers that you can only have 80% of the capacity, the quality manufacturers actually show the graph all the way down to 0% state of charge and show what the actual voltagecurve compared to capacity is, nothing hidden.
    The next thing to understand, 0% state of charge isn't the point where every scrap has been drained out of the battery, it means all the advertised capacity has been drawn out of the battery at the advertised C rated load but it still maintains 3 volts in each cell while still under that load.

    The antics some drop in battery resellers get up to are real eye rolling stuff and really p*sses me off.
    Take this one asan example, https://itechworld.com.au/collectio...itech120x-water-proof-ip67-380a-max-discharge
    They sell this as a 120Ah battery, but the specs say

    SPECIFICATIONS
    Nominal Voltage: 12.8v
    C20 Rating usable amps 10v:105Ah

    That means the discharge rate is only 5.25 amps and dragged down to 10v.

    Here is another example
    https://www.ebay.com.au/itm/333701520490

    The graph is meaningless, none of the lines actually correspond with any of the figures, it doesn't mention what the load is, but again it is dragged down to 10v so the last bit can be milked out.
    The other give away is the weight, just like lead, they don't make light weight lithium compounds, plus they also have a battery management system inside the case, that has to weight something, doesn't it, but in the specs it is 12.9kg, it should weigh more than 20kg if it really has the capacity they claim.
    Here is a Winston 130Ah cell as a comparison, https://en.winston-battery.com/?cnxdc/317.html
    it requires 4 of these cells to build a 12.8v 130 Ah battery, so multiply the weight of a single cell by 4.

    Here is what I would consider proper 12v lithium battery specs should look like https://en.winston-battery.com/?qdxdc/320.html

    If you scroll down to the first graph, the battery is charged at 45 amps, C2 or charged from 0% to 100% SOC in 2 hr, then discharged at the same 45 amps over 2 hrs, all 90 Ah and stops at 10v while still under the 45 amp load. These they sell as start batteries and are the older LFP chemistry, Lithium Ferrous Phosphate of LiFeP04, their house batteries (as in the link above) are built up from individual cells with the newer LYP chemistry, Lithium Yttrium Ferrous Phosphate or LiYFeP04. The advantage of the yttrium chemistry is a wider operating temperature and longer cycle life.

    We have a lot of this LYP chemistry cell batteries that we have build up for customers that are over 10 yrs old now, all work 24/7 because they are off grid batteries in houses, caravans, motorhomes, camper trailers and house boats. All of them have returned better than 100% of their advertised capacity when load tested at the factory C2 rate, or discharged from 100% SOC down to 0% SOC over 2 hrs, and still holding better than 3v per cell while still under load.

    This is not a plug for my wife's business, I'm just putting this forward to show what a good quality lithium house battery with a good battery management system can achieve. A quality system is not cheap, just like a quality Kombi, but you don't have to pay crazy prices, but no one should expect gold standard quality yet want to pay lead quality prices ;)

    Look to see what the "C" rating is, look to see if they are using the "80%" usable capacity, a battery advertised as 125Ah and a 20% maximum Depth of Discharge (DoD) is really only a 100Ah battery, comparing apples with apples to compare the price can be a very tricky business, but if you keep your eyes open, you will spot the traps.

    Another thing to look out for, a recommendation of how great XYZ battery is from someone who has owned it for less than 12 mths, isn't much of a recommendation, if they have used it 24/7 for over 5 yrs is the sort of recommendation you are looking for if you want a system that lasts.

    T1 Terry
     
    Last edited: Dec 4, 2021
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  18. Squalo

    Squalo Active Member

    Messages:
    220
    Location:
    Sunshine Coast QLD
    Mine is a Betta 6-CNFJ-100, it's 100AH (not 110 as I stated). Purchased Dec 2017 from JTS along with a power pack containing a Redarc BCDC1225-D charger. I wired it all into the vehicle myself.

    Thanks Terry, I'll get onto that.
     
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  19. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,770
    Location:
    Mannum South Australia
    As a drop in, the iTech World offering isn't all that bad, just the 120Ah is really only 80Ah and to join multiple drop in batteries in parallel is a huge task. I did it as a project for a customer a few mths back, only two of the 120 model batteries and the hrs spent getting the 2 batteries to work together was huge, way more expensive than a single 4 cell Winston 160Ah battery costs, complete with the external BMS and WiFi battery monitor.
    Nothing like a battery that just shuts down with absolutely no warning to make you day exciting :rolleyes:

    T1 Terry
     
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  20. drivesafe

    drivesafe Active Member

    Messages:
    251
    Hi Squalo and that charger is too SMALL for that Lead Crystal battery.

    I use to sell Lead Crystal batteries when they first came on the market and it was quickly determined that to maintain them properly, you need a charger that has at least a 30% current rate based on the Lead Crystal's Ah, so to be able to maintain your 100 Ah Lead Crystal battery, you need a battery charger that is of at least 30 amps and a 40 amp charger would be better.

    The high current charging is periodically required to cause the water in the battery to turn into vapour during the charge cycle, allowing it to remix properly and evenly in the whole battery.
     

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