| Archive for Downsizer For an ethical approach to consumption |
| Bulgarianlily |
Alum to remake old batteries?http://blog.hasslberger.com/2007/01/how_to_convert_a_lead_acid_bat.htmlLooks interesting, has anyone tried this? |
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| RichardW |
Sounds like hocum to me but I am not qualified to say.
Have asked some one who is. |
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| Bulgarianlily |
http://www.boervolk.com/forums/showthread.php?t=943
A report here where someone who seems to know about batteries has tried this out. |
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| RichardW |
Had a reply
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| crofter |
I think it sounds shonky too. But interesting to read the comments from people who claim to have done it. Although it looks like they don't even know what they are using?!
Or for something different...
I am sick of batteries that only last a year or two, but life's too short to mess around cleaning out the old ones and experimenting with new electrolytes. |
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| RichardW |
Buy better batteries & look after them better (normally means charge them more often & for MUCH longer than you would think) Richard |
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| crofter |
Bought some chinese (eek!) batteries a few months ago that are supposed to have a 12 year life. Time will tell. (These were for a small wind turbine) Also bought a ctek charger (eg http://www.vertar.com/ctek/ ) which will hopefully help preserve the tractors/quad etc. Any reccommendations for good/better brands? |
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| jema |
It never ceases to amaze me how people without even 'o' level chemistry think they can invent something that the rest of the world is missing. Though maybe if this actually comes down to the fact that replacing spent acid in a lead acid battery might revive a battery it might actually be an idea to work on properly. | ||||||
| dpack |
drain ,wash ,fill with 25% sulfuric ,job done if there is any lead left in the box
get a posh charger with fast ,full and recondition modes ,bout £60 for a good un start with the best batteries you can afford iirc 80ah is about £50 via tinternetthingy lots of nonsense talk re batteries but they are more complex than charge /use /charge if one is to get them working as well as can be ps old car batteries are not ideal for energy storage for low current use ,such as electric fences ,sealed and /or gel works for pv storage ,large capacity leisure batteries work best to give a steady current to inverter or lights it isnt rocket science ,it is much older than that once one sees the spec choosing a battery is easy |
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| RichardW |
Which Chinese ones? I guess you are talking about small vehicle (quad & tractor) type bats then. Keep them topped up (fluid & charge). If poss keep em warm. I was on about BIG off grid types. |
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| crofter |
These are the ones I got for my windmill http://www.hazebattery.com/6&12VGel/default.htm Hopefully the 12 year working life is true. |
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| jema |
Re: Alum to remake old batteries?
Just been looking more at the site. It is littered with barking mad articles 
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| RichardW |
Gel bats are not a good idea for off grid or "green" charging.
1, you cant top up the acid / liquid 2, you have to charge them slower 3, they die if you over charge them 4, they die if you charge them to fast 5, they have a lower charge & discharge max amps, size for size 6, its very difficult to EQ charge them They will only last longer IF you treat them with kid gloves. They are better for uses like back up systems that are on trickle 24 7 & only get discharged during power cuts & can then be recharged slowly when the power comes back on. Oh & I forgot to add 7, IF they are not valve regulated they can blow up if charged to fast, if valve regulated (yours are) they just blow of the acid jell (which cant be replaced) if charged to fast |
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| crofter |
12 years might be optimistic then 
There is a regulator between the windmill and the batteries (this one http://www.marlec.co.uk/products/windchargers/windcharger-controllers/hrsi-charge-regulator/ ) so shouldn't get overcharged? What do you mean by EQ charge? |
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| crofter |
Re: Alum to remake old batteries?
Yes. I never realised the moon was inhabited! |
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| RichardW |
EQ = Equilisation charge. The makers say you dont need one but you do, but then that say to charge at the same V as a lead acid ones & that will kill them. I cant see that you can alter the controller for dif battery types so I would be slightly concerened. |
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| toggle |
Re: Alum to remake old batteries?
it passed the true frootloop test, it's talking about von daniken |
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| crofter |
No, you can't. And since they are sealed I won't even be able to recondition them with alum! |
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| RichardW |
Do you have any battery monitoring hard ware or test kit (multi meter, SG tester [oops cant use one of them on sealed bats], amp meter)
Would be interesting to see how well they are getting charged & at what amps & volts during the differing charge stages (bulk, absorb / acceptance & float plus an EQ as needed) |
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| vegplot |
Agreed. |
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| crofter |
I've got a multi-meter, but how would I know which stage of charge they are at? Normally both lights on the regulator are green, if there are a few days with light winds/no wind the battery light might turn amber (12-13v) and once or twice it has been red (below 12v) I suppose I could connect a big spotlight and drain the batteries a bit? |
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| RichardW |
Those lights are as much use a a choccy fire guard.
They band the volatge in 12-13v etc. To be accurate you need to be talking about 0.1v incriments with an accuracy of 3% out or better. roughly for lead acid bats the volatge when measured at least 10 hours after any load or charge has been applied 12.8 = 100% 12.7 = 90% 12.6 = 80% 12.5 = 70% 12.4 = 60% 12.3 = 50% NEVER EVER go below 12.3 at rest. So your amber light could mean a total flat bat or a total full one. Your green light is only of value IF its not under charge or discharge. Oh & over 13v whilst charging is also not helpful as yes the bats will charge full at 13v but you might not have enough time for it to do so. You really need to get up to 14.4 - 14.8v to charge in a sensible time (you can do it higher but need special "skills" in battery management to do so). How do you decide its time to put the genny on? |
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| crofter |
There is no back-up. The batts are mainly to power a fence plus (occasionally) for light. I am not there every day, but when the red light comes on I plan on switching off the fence until there is enough wind to bring the batteries back up to "green" I thought I had plenty of capacity (2x100Ah batts) and would never need to turn it off, but it is looking like I need a "spare" battery for when there is a week with light winds. What are the special skills you mention? |
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| dpack |
is the fence shorting out to earth?
my 3 w pv rig keeps the chookmobile1 joule energiser powered that puts about 17v in greylight to a small sealed battery and seems to work very well (nastiest fence to be bitten by at rosewood ) but there is no discharge to earth and a short run of wires on prongs to stop moos bending the chookmobile i find an 85ah lesure battery will run 2joules to 150m poultry net for a month if it is dry and a week if it is wet using a 50m net and a cardboard vegitation control at the fence base seems to use very little energy round dpack corner to repel piglets etc ,i will scale up when we need all the nets what is the output of your windmill? |
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| RichardW |
mainly having the right tools & knowing how to use them & then interprit & acting on the info. Plus keeping them topped up which you cant. At higher V the water used goes up LOTS plus the total efficiency goes down (IE for every 50ah used you might normally have to replace 60ah but at high V charging you will need to put back 70ah). But the gain is if you are genny charging the genny is on for less time.
I keep to the standard 14.4-14.8v change over from bulk to absorb level. Bulk phase is when you get the most charge back in to the bats & will take you to 80 or 90% SOC (the faster you charge the lower the SOC will be when it changes). During this phase the amps fall & the V climbs till the set point is reached. Then during the absorb / acceptance phase the V is held at the set point. That happens either till the charger reaches a set low amps level or a fixed amount of time is reached or some use a formula of how long the Bulk phase took (not a good idea). Then once that stage is complete it should go into float mode at about 13.?v to keep the bat in good condition. When a load is applied it will first be powered from any power being made then from the bat. How big is the turbine? How windy is the site? When the red light comes on you have discharged your bats to far. Do that a few times & the bat is stuffed. Also failing to recharge to 100% SOC allows the bat to sulphate. That has the effect of making the bat act like a smaller one. Say you only ever recharged to 90%, then the bat becomes a 90ah one if it was a 100ah one. Then you carry on doing that & it becomes a 81ah one. Very soon you have a bat that is very small in available capacity. Bats dont die they get murdered. |
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| dpack |
a smart charger is good if one has mains ,the thing checks batteries and deals with them on what it detects
the 14v+ thing is good |
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| crofter |
Excellent post Richard, I am learning a lot from this thread. Never realised this was so complex. Don't think the fence is shorting out, (but ? might be...) Windmill is 24w @ 10 knots, normally plenty of wind. Red light has been on a couple of times that I know about, seems to work fine just running the fence but I need lights there sometimes too. Should be less calm days now that winter is almost here... |
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| dpack |
24 watts should be plenty to keep a fence energised
im puzzeled |
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| RichardW |
I'm not. 24watts is NOTHING when it needs to charge a battery. Its less than 2amps.
If I remember right you said the batts were 110ah & you had 2. so thats 220ah. The recommended charge rate is roughly 10% so you need a 22amp charger. By the time the energiser has taken its bit you are only going to have less than 20watts left IF the turbine is running at full power. I would hazard a guess that its not running at full power very often. If you are getting less than 1 hour(with a 1w energiser) to 5 hours (with a 5watt energiser) full power per day from the turbine (on average) then the bats are not getting any charge at all. Its very obvious that your bats are getting under charged. |
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| dpack |
the size of storage matters
thanks ,my pv rig has a small battery from a lamping kit as the store would it be worth reducing the battery size for the fence/windmill and mains charging the big ones for when you need more power ? |
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| RichardW |
Its all about balance.
You need to size the storage to match the load & how often you want to manually intervien. The storage size then dictates the charging needed. Things like this should not be speced on what you can afford. Better to not do it than do it badly. A smaller bat needs a smaller charger but will give you less time between intervention or you need a more reliable solar / wind source. Plus with a small bat you can go from ok to flat quickly & so are more likely to damage the bats. But having a big bat & a small charger means the bat never gets full so gets damaged any way. Best is to have two sets & rotate them having mains charged them up for a few days. Or a much bigger PV / wind charger sized to meet the needs of the system & its location. |
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| crofter |
It is fine if I am just running the fence, but even then maybe problems if there is light winds/no winds for a while. 24w is minimum, not the maximum, (that is what it produces at startup speeds) think the maximum is 300w. It generates 90w @ 19 knots, then improves as the windspeed increases. But maybe a better setup would be as dpack suggests and have the 2 batteries separate, although I am not going to use mains because it is too much hassle to move the batteries around. |
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| RichardW |
Your turbine is one of those that look good on specs but actually perform badly. 19 knots is 9.77m per second. 10 knots is 5.4 MPS.
Do you know your average wind speed for the height of the turbine in your area? Ours is 6mps averaged over the full year. Our turbine starts producing at 3mps & is rated at 200w at 6mps. I think yours is one of the ones rated at 35mph which it will virtually never see. At lower speeds its turning but not producing much. It would be interesting to see what it actually is producing. It could also be how far from the bat the turbine is & the size of the cable.
Not if you keep needing to change the bats its not. Some time though its cheaper to keep replacing the bats than install a system that works 100% of the time. Two bats & rotate them & charge on mains works well but does need regular intervention. |
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| crofter |
Not for my turbine. But mean annual speed for a comparable site was 15 knots.
Batteries are in a box at the base of the pole, (about 4m from the windmill) 2.5mm cable. I got gel batteries because I wanted a "maintainence free" setup, can't charge batteries on the mains because it would be too difficult moving batteries back and fore (no road) Would it be better to rewire as 2 separate batteries, to ensure each gets a full charge while the other is working? (assuming the wind cooperates) |
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| RichardW |
Doing it with two sep bats will help get one fully charged but will the other one last long enough to allow that one to be charged & how will you monitor the SOC of the one in use so that you dont over discharge it? Remember you will still have the same amount of charge & the same amount of load even if you split the bats up. | ||||||
| crofter |
Good point. But I could improve things by replacing gel batts with wet, and installing a voltmeter. I guess I could invest in a meter and see how it goes with the gel batteries, for the time being. | ||||||
| RichardW |
Yeh no point ditching them. Try to charge them on mains if you can occasionally. |