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Forum Index : Other Stuff : batteries
| Author | Message | ||||
rippa01 Newbie  Joined: 08/02/2010 Location: AustraliaPosts: 11 |
hi all I have some cells in my batteries that are starting to die, is there some way of opening and reseal them so i can see why and fix them if possible. there are 2x2v cells per yellow box and each cell is 550ah. chris 
tell me, I hear show me, I see involve me, I understand |
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SSW_squall Senior Member  Joined: 20/03/2010 Location: AustraliaPosts: 111 |
Starting to die how?? Assuming they are LEAD-ACID batteries: Are they flooded (wet cell type) or sealed AGM (absorbed glass mat) type?? If flooded: check the water level, like you would in a car battery. Check the Specific gravity with a hydrometer to find any weak cells If sealed: They may need to be rewatered as even sealed batterties seem to loose water through the vents over time It is important for any lead acid battery that they be held at saturated full charge 14.4V every once in a while, so all the cells can get to an equally high state of charge. If left significantly discharged for any significant length of time the battery will become "sulphated" Refer for more info on sulphation: http://en.wikipedia.org/wiki/Lead-acid_battery AB Einstein: Everything should be made as simple as possible, but not one bit simpler |
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Tinker Guru  Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Chris, How about a picture of your batteries, looking down on the top of 'em? I would think 'fixing' a wet battery's inside is well beyond DIY range. Klaus |
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| rippa01 Newbie Joined: 08/02/2010 Location: AustraliaPosts: 11 |
Is to much water as bad as not enough. each yellow box contains 2 cells. over the last 6mths 3 cells have lost charge and have ended up with 0v when checked with a multimeter. they have a small hole in the top which is covered by a rubber cap and then a top made of the same plastic as the batteries. when i bought them 1 year ago, the guy said that i should top up the batteries with water. I checked them last weekend for water level which was fine and on the hydrometer the level was on the white. To charge the batteries i have 4 123w panels running through a PL40 which says they are full around mid morning. (i read in another forum that while they say full Volts wise they may not be getting their capacity topped up) the steel that is connecting the batteries together where they bolt onto the terminals has been ground back to shiny metal and covered with vasaline to help with corrosion. when in town today i will be buying extra diesel so i can give each bank an individual charge for half an hour to give them that saturation charge that was mentioned. it is inconvienient as it is only one cell from a number of containers has gone. 
tell me, I hear show me, I see involve me, I understand |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
I have never seen iron used for cell interconnects on a battery. I don't see joiners between the parallel strings either. iron forms a high resistance joint quite quickly. These cells are not designed for cyclic discharge applications. More like a big UPS. Flooded cells need the electrolyte to be able to be gassed, to allow mixing to prevent stratification. Sounds like you have some problems to sort out. Gordon. become more energy aware |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Rippa, as Gordon mentioned above, there is something very odd about your battery connections. Can you post a picture that shows the whole top of your battery bank so we can see just how you have connected them. There should be no unused terminals. With the heavy currents that can flow at a battery bank its bad economy to skimp with the connecting links and wire size/ terminations. Do it well once or fiddle forever with poor connections 
Also, I do hope you used de ionised water and not tap water to top up the cells. Tap water is really bad news. Klaus |
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KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Batteryworld in Mareeba Queensland the guy is brilliant will take the lids off fix as required and put em back together again God know how much it costs but he seems to do quite a lot. should be on dirty jobs... 1/2" copper pipe flattened makes good buss bars and cheap as dirt now, can tin them with a little solder to make em survive longer too solder on rag to wipe off leaves nicely tinned bars. I think that was Gizmos idea these are mine, note the parallel strings have bars across so nothing should get too out of balance battery interconnects 2 strings 48V Looks like batts are externally in good nick, perhaps an expensive mistake Luck favours the well prepared |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I think rippa's batteries may have died, cant get back on the forum to reply to all this advise  Luck favours the well prepared |
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| rippa01 Newbie Joined: 08/02/2010 Location: AustraliaPosts: 11 |
hi guys thanks for all your info, was off in toowoomba doing easter things. only three cells have died. 
the batteries are ex phone exchange i will take a photo for you so you can see how they are connected. as seen in the previous photo they sit side by side. each row was connected in series with the metal strips and then connected in parralel at either end of the row using copper strip. some of the cells cant be used as the ones that have lost capacity to hold charge and wont make up 12v for charging. (unless i hook them up similar to the way karl has) which looks to be a better set up then mine 
i had looked at using copper, i should go that way after all will get back to everyone shortly hope you all have a happy easter chris tell me, I hear show me, I see involve me, I understand |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Re point 1/. The plasmatronic unit is has float, boost, and equalize voltage settings, and equalize, and boost timing settings. Are you able to provide these?? The unit is also a good battery maintenance tool, if the settings are correct for the battery type. Re point 2/. A half an hour on the genset will do nothing for the battery if it is flat. The 500Ah battery will require 50A for a full 10 hours to recharge. Most likely, the current will reduce as it charges, so the time to replace the amp hours will need to be longer. Is there visible signs of bulging of the battery sides?? A flooded cell battery requires a monthly service reigime, to check electrolyte and connections etc. I think you will find the battery has consumed electrolyte, and will require topping up, and then possible continuous charging for up to a week to recover some capacity. I would not suggest using the diesel, but possibly finding a grid connection for this. I know of a battery that was discharged so the electrolyte was only water. This battery was recovered after a week of solid recharging, with periods of manual boost and equalize in subsequent weeks, and now performs close to original specs. This was a new battery, and the older the battery the less likely the recovery.. It is likely the telephone exchange battery is quite old, even though it looks good. Most batteries in these applications are replaced when the battery is about 60% of the original marked capacity. These batteries have to be almost given away, as the performance will be way down to a new battery. In the exchange application, the battery spends a lot of its time at float voltage, and the plates increase in impedance over time, without necessarily losing much capacity, so even if the capacity is still there, the ability to supply current is diminished. The fact that some cells are dead now is an indication that there are others not far behind.. Gordon. PS: I am using 2nd hand batteries still that were in a poor state when I got them. After 3 additional years, with my TLC, they are towards the end of their life now. become more energy aware |
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| rippa01 Newbie Joined: 08/02/2010 Location: AustraliaPosts: 11 |
thanks gordon i will have to save the dollars to buy some proper solar batteries. topping up the electrolyte shouldnt be a problem, might be able to get some from the auto store in town the PL40 lets the voltage get to 14.1v before it changes modes. the volts are set at 12 and the amp hours is set to 1.1 not sure how to set the other timers (thought they were automatic given the volts and a/h settings) the neighbour in the next valley has mains power, he may let me use his place. will have to aquire a charger of the right size. the deisel was for the cruiser, was going to use the altenator to charge up each bank. not enough for 10hrs though. thanks for all of your info and help i will make the neccassery changes and see how i go will keep you up to date chris ps. here is the photo of how i have the batteries hooked up 
tell me, I hear show me, I see involve me, I understand |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
I think you will need to read the plasmatronics manual, on how to set the various parameters. It is available online, if you don't have a paper copy. You should spend a little more time framing your photo, to give all the connections. We still have to guess how it is wired. The lack of cell interconnects will resusult in potential for cell imbalance, with poor connections in a series string. This is a 12V setup, so is really only good for a max 300-500W, given the wiring you have shown. Gordon. PS: If you think over a 1000W is possible, then you would need the inverter right next to the battery, and it is not shown that way. become more energy aware |
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| SSW_squall Senior Member Joined: 20/03/2010 Location: AustraliaPosts: 111 |
Hey rippa, your bank does look impressive even if it's not quite performing to expectations... Second, GW's comments about the charging it these kind of batteries need ALOT of amps for a sustained period to pull the voltage up. I've got a 48V second hand electric forklift battery that is of a similar size. The charger that is we use on the forklift at work puts out 80A!!! It's a 3 phase job about the size of a large bar fridge that has two massive transformers wired in star-delta with a 12 pulse rectifier. The diodes mounted to a heatsink are each about the size of a 10 cent coin!!! My solution for high power charging is to get a stick welder hooked up to a couple of 35A bridge rectifier in parallel, connected to 6 4700uf 80V filter caps in parallel. The control knob on the welder allows some control over the current output from the charger. If you have access to a 2.4kVA generator or similar you could use that to power the "charger". The other thing about old deep cycle batteries, is that the self-discharge can be quite high %10 per week as opposed to 1-2% for a new bank. The self discharge is actually worse at higher temps, just another reason to keep batteries cool(20degC)but not cold AB Einstein: Everything should be made as simple as possible, but not one bit simpler |
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