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Forum Index : Solar : Battery advice
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Tim_the_bloke Senior Member  Joined: 15/11/2009 Location: AustraliaPosts: 105 |
I am seeking advice on what batteries to purchase. I have an off grid shack running 12 volt lights and appliances. The current batteries are ageing and insufficient for increasing numbers of gadgets wanting power. Currently I have 2 independent banks of 3 batteries each. If/when one bank gets run down too much, I switch to the other bank. So 6 batteries, each being 12 volt, Crown lead acid 215Ahr each. Each bank is 3 batteries in parallel. I top them up with rain water regularly. Are gel batteries better? Any gossip on when Gelion batteries will hit the market? |
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Revlac Guru  Joined: 31/12/2016 Location: AustraliaPosts: 961 |
If you don't want to go the with lithium, you can look into CARBON GEL BATTERIES or sun gel batteries. Cheers Aaron Off The Grid |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 379 |
Hi Tim, depends on how big the loads are that you are running. I have BAE Valve regulated sealed lead acid batteries on the house.I have 12 x 2 volt cells 660 amp hour. So run a 24 volt system. I use 24 volt to 12 volt converters to run the 12 volt stuff like lights and 24 volt inverters for the 240 volt stuff. I also have a smaller system with AGM batteries on a small cabin too. That is also 24 volt setup with 24 volt to 12 volt converters for lights and 12 volt things. I have seen plenty of stuff about lithium batteries on this and other sites,and like all things it seems to depend on the quality of batteries you buy. For me, Lithium batteries require too much complicated circuitry in cell balancing etc. I did have problems with starting large loads,( air compressor mainly) on my 24 volt inverters but added a 500 Farad bank of capacitors in parallel with my batteries and everything starts as if on the grid now. good luck Pete |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 961 |
I don't see myself going back to FLA, for any deep cycle application, unless it was dirt cheap,  I still prefer FLA for engine starting.Cheers Aaron Off The Grid |
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| Tim_the_bloke Senior Member Joined: 15/11/2009 Location: AustraliaPosts: 105 |
Thanks for the replies. Now reading up on sun gel batteries. There are so many batteries on the market. Lots of reading to do. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577 |
Traction batteries ( forklift) are without doubt the best bang for the buck available. They are proven with decades of use and have an average life expectancy of 17 years from all the people I have spoken to. You can buy a 40 Kwh useable pack brand new for $7K and cheaper for smaller or used packs which have good service life. One thing about traction packs is they are wroth 25-33% of their price as scrap when they are done which makes them even cheaper. There is a LOT of Misinformation and slander ( as well as pure ignorance) leveled at Traction batteries. Most of it is from vested interests that make a LOT more profit selling Lith batteries than they do LA. This is a very good group for knowledge on Traction batteries with many people using them and having much experience even with rejuvenating them. https://www.facebook.com/groups/448656667134549 |
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Clockmanfr Guru Joined: 23/10/2015 Location: FrancePosts: 427 |
+ 1, what Davo99 just said. Everything is possible, just give me time. 3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v. |
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| Tim_the_bloke Senior Member Joined: 15/11/2009 Location: AustraliaPosts: 105 |
So what do you mean by Traction batteries? Is that what you would call my Crown lead acid 215Ahr batteries? I could just buy more of them... |
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| pd-- Senior Member Joined: 11/12/2020 Location: AustraliaPosts: 122 |
Like this https://batterytechnologies.com.au/product/forklift-batteries-australia-wide/ Its a common product so cheaper than buying via the solar power industry |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 584 |
Traction batteries are the ones used in electric fork lifts as I understand it. The problem with them is that you need a fork lift to move them  .Otherwise not a bad choice if one is set for wet LA batteries. |
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| Tim_the_bloke Senior Member Joined: 15/11/2009 Location: AustraliaPosts: 105 |
In years past I bought lead acid batteries which needed topping up often with rainwater. I don't understand how lead acid batteries can charge without using up the water in their acid. Those bubbles come from water disappearing. I don't understand how sealed lead acid can work. But they must. I would love to not have to worry about the maintenance as I am not always there to do is, that is top up with water. Also, some family will flatten the batteries with too many gadgets plugged in. My solution has been to swap to the other gang of batteries, but this is too hard for other family members. It deserves an upgrade. What batteries can I install and not worry about them? |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 379 |
Having a stand alone system where people how have no idea how to manage the system and no interest in it is very hard. No batteries like being abused. If the people who stay at the shack are not interested in looking after an expensive set of batteries for you, then it is probably better not to let them stay there. Flattening one set of batteries then switching to another set to flatten them is not a solution. Possibly a set of Nickel Iron batteries would work, but again you would have to fork out lots of money. Pete |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1788 |
This won't make you popular. A low battery verbal alarm that tells them to switch off all non essentials, followed (at a slightly lower voltage) by disconnection of all circuits other than minimum lighting and fridge. If they comply the voltage will rebound delaying disconnection. |
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| Tim_the_bloke Senior Member Joined: 15/11/2009 Location: AustraliaPosts: 105 |
An expensive solution would be to set up a system with lots of capacity so they never flatten the batteries. Perhaps I should get some commercial solution and lean on family to contribute to the cost. You give me much to think upon. |
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| Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 584 |
Sealed batteries re condense the 'bubble' gas into water, it's done in the top of the battery in some kind of labyrinth of passages. I'm using lithium batteries. All maintenance is purely electronic and does so by itself if properly set up. Yes, its an expensive solution but I'm very happy how they perform. |
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| noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 506 |
most traction batteries have a central watering system... one of the 2 banks I have do, extremely easy, plug in the hose until all the " white buttons " pop up.. done .. takes 5 mins if that... my other bank has rubber " plungers " that mostly seal the top, significantly reduces the water usage ( only need to top that bank up every 2-3 months or so).. not to detract from lithium, but flooded lead acid are very forgiving for stand alone systems... especially forklift batteries, they are designed to work hard.. once you place them where they belong, they stay for many years so the weight is really irrelevant, and as was stated above once those many years are up you can scrap them for a significant amount of there original price.. I think it works !! |
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| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1788 |
Other water saving tricks used in SLA batteries include using high purity lead to minimize the production of hydrogen and a calatyst in the labyrinth that reacts the hydrogen with oxygen to turn it back to water. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577 |
The watering things seems to be overplayed a lot. Like Noneya says, the people I have spoken to with them only water them about every 3-6 months and takes no time at all with the auto watering systems. I was reading the other week that the batteries can now be topped up with regular city tap water. Does not need to be distilled at all. I think those that are having to top up all the time probably don't have their Charging levels set up right. A battery shouldn't heavily gas other than with equalisation charge and as that's done briefly once a month..... People I know that have been off grid for 40 years and ran a dairy tell me they only top the batteries about twice a year and were a bit miffed their last set " Only" lasted 14 years where they normally get 15+ and their current set was 11 and still showing no signs of lack of capacity. Admittedly since closing the dairy about 8 years ago the load would be a lot lighter but they were getting good life before that. On another forum I am on, a number of people get the dead Fork batteries and rejuvenate them by draining the acid, filling them with water and draining it out then refilling and Charging. TBH, I would have said that this would have been extremely marginal as far as capacity goes at very least but seems several people are doing it and I trust what they are showing and what they say. Most are claiming they are getting circa 80% original capacity and I don't see them making any other questionable claims or grandstanding and they certainly seem to know what they are talking about with regard to their setups. Seems they usualy try to buy as many batteries as they can and then go though them and get out the best ones. They readily admit they don't all come up but they certainly get enough to make the exercise Viable and they get them cheap enough to make multiple packs which even at diminished capacity still add up to a ton of reserve at a laughably cheap price. i have a number of dead car batteries up the back so I was going to try this to see if I could get any response out of them. My position is the decline is basically Physical damage but there is also the possibility of shorting and formations on the plates that hinder the chemical reaction. If this can be removed, then it would seem reasonable to me that the battery could have a second if reduced performance life. If you got say 5 years out of a pack that cost you 20% of the going price for good used packs, then to me one would be on a winner. |
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Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 639 |
I used to be in the lead acid world. That's long gone for me. Disclaimer - I sell Winston lithium. Lithium does cost more but the benefits are big. 1) Low internal resistance. Low light conditions can still charge lithium some. Lead acid get nothing in low light condition. Lead acid with a higher internal resistance require the solar voltage to be much higher. 2) High charge/ discharge capability, means less voltage tension or sag. Can be charged/ discharged at 3 times its capacity. In peak sun on my house solar I have a potential of 240A to the batteries. My 7000W inverter has a 20,000W peak for 30 seconds. 20,000W / 56v is a potential of 357A. In my EV Hilux, at full throttle is 1000A, T-Rev is 500A. Welding and other big ticket items is no problem from Winston Lithium. 3) Lighter. I know weight is not a big plus for solar, but makes installation easy. A 400Ah cell (3.2v) is 13.5kg. A 200Ah cell is 7.9kg and 300Ah cell is 9.7kg. Anyone can pick those up. 4) Safe chemistry. Out of many thousands of kilograms bought and sold, I have had one cell that developed a dead short and did not go into fire. 5) High cycle life. I speak with experience. I have posted about EV Hilux and House solar Winston lithium in other threads. New cells on a house solar system, you can expect 15+ years. Maybe 20 years. The pitfall is, at zero volts the cell dies and will not come back to life. It is important to protect from going to zero volts. My solar system thread https://www.thebackshed.com/forum/ViewTopic.php?TID=6010&P=1 Trev @ drivebynature.com |
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kevinbacon Newbie  Joined: 21/12/2023 Location: AustraliaPosts: 1 |
One of the best advantages of lithium batteries is their long lifespan and extended battery life. The short downtime for charging is another advantage. Battery welders (like this example) are becoming an ever popular choice due to the mobility they allow for and ability to work in any off-grid situation. As a professional welder myself I have certainly seen a growing trend towards lithium and I only expect this to grow further in this current decade. |
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