|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Lead acid battery desulfonation
Been using my 12V battery minder desulfonator on my 24V series SL battery pack. 12 V SLA batteries wouldn't charge up indiviually on the 12 individual batteries, but when I put the Battery minder accross the 24 series pack, the battery minder started it's desulfonation pulsing. Whe the desolfonater is remove, the SLA batteries are at 14V total rathe than their prefferred 24V, so not sure if the experiment is progressin yet. Does a SLA battery with sulfonated plates appear as merely a hig internal resistance battery, or will a cell appear shorted or open -- meb |
Ads |
#2
|
|||
|
|||
Lead acid battery desulfonation
meb wrote:
Been using my 12V battery minder desulfonator on my 24V series SLA battery pack. 12 V SLA batteries wouldn't charge up indiviually on the 12 V individual batteries, but when I put the Battery minder accross the 24V series pack, the battery minder started it's desulfonation pulsing. When the desolfonater is remove, the SLA batteries are at 14V total rather than their prefferred 24V, so not sure if the experiment is progressing yet. Uh-oh. It sounds like your battery conditioner is intended for 12V, and wrecked your pack. Anything less than about 21V on a 24V pack, even for a short time, usually means it's time for a new battery. I suggest hooking your batteries up in parallel, instead of in series, to the same battery conditioner. You haven't got much to lose at this point. Might as well see if they can be saved. Chalo Colina |
#3
|
|||
|
|||
Lead acid battery desulfonation
Chalo Wrote: meb wrote: Been using my 12V battery minder desulfonator on my 24V series SLA battery pack. 12 V SLA batteries wouldn't charge up indiviually on the 12 V individual batteries, but when I put the Battery minder accross th 24V series pack, the battery minder started it's desulfonation pulsing When the desolfonater is remove, the SLA batteries are at 14V tota rather than their prefferred 24V, so not sure if the experiment i progressing yet. Uh-oh. It sounds like your battery conditioner is intended for 12V, and wrecked your pack. Anything less than about 21V on a 24V pack, even for a short time, usually means it's time for a new battery. I suggest hooking your batteries up in parallel, instead of in series, to the same battery conditioner. You haven't got much to lose at this point. Might as well see if they can be saved. Chalo Colina This 4 year old pack Twas already wrecked before I tried conditionin accross the 24V, so that is why I tried saving it by running the 12 conditioner accross the 24V serries terminals. The other 4 year old 2 V pack still is fine. I usually run the conditioner accross the 12V SLA batteries separately but when that failed and noticed the sum voltage was just under 12 instead of 24-26V, I though lets try this. I've seen the two 12V batterries in the pack rise from 5.7-5.5V each t about 6.5 V, so there is some encouraging improvement. The 12V and 24V chargers are sending out 1 A, but never reached charged state. I wouldn't expect to see an intermediate voltage like have if I have an internal cell open, but might if I have an interna shorted cell or if resistance was ultra high due to sulfur deposits, s was wondering if anyone knew the fail mode? If it is merely an ultra high internal battery resistance, I woul expect to be able to recover the batteries with the conditioner accros the serries combination. If shorted, perhaps a solution would be to place the conditione accross the separate 12 V batteries with a 10 ohm power resister i serries between the battery and conditioner. However, the low voltag -- meb |
#4
|
|||
|
|||
Lead acid battery desulfonation
On Fri, 15 Jul 2005 17:36:42 +1000 meb
wrote: Been using my 12V battery minder desulfonator on my 24V series SLA battery pack. 12 V SLA batteries wouldn't charge up indiviually on the 12 V individual batteries, but when I put the Battery minder accross the 24V series pack, the battery minder started it's desulfonation pulsing. When the desolfonater is remove, the SLA batteries are at 14V total rather than their prefferred 24V, so not sure if the experiment is progressing yet. Does a SLA battery with sulfonated plates appear as merely a high internal resistance battery, or will a cell appear shorted or open? From your description, it's really quite hard figuring out what you've actually done, but I THINK that you've put 2 12V packs in series and then put them across a 12 V charger because they measured about 12V total when in series. The short answer is that if a lead acid battery measures significantly less than 2V per cell, then it probably has shorted cells. The only cure for shorted cells is replacement. Sulfated cells are different. They will show a high cell voltage with a small charging current. If you charge them VERY slowly, they are often recoverable. An appropriate charging current would be about 0.1% of it's amp-hour rating. Expect this to take a week or 2 to work, if it is going to work at all. Trying to recover a sulfated cell faster by charging it faster only reduces your chances of success. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
#5
|
|||
|
|||
Lead acid battery desulfonation
Jim Adney Wrote: On Fri, 15 Jul 2005 17:36:42 +1000 meb wrote: Been using my 12V battery minder desulfonator on my 24V series SLA battery pack. 12 V SLA batteries wouldn't charge up indiviually on the 12 V individual batteries, but when I put the Battery minder accross th 24V series pack, the battery minder started it's desulfonation pulsing When the desolfonater is remove, the SLA batteries are at 14V total rather than their prefferred 24V, so not sure if the experiment i progressing yet. Does a SLA battery with sulfonated plates appear as merely a high internal resistance battery, or will a cell appear shorted or open? From your description, it's really quite hard figuring out what you've actually done, but I THINK that you've put 2 12V packs in series and then put them across a 12 V charger because they measured about 12V total when in series. The short answer is that if a lead acid battery measures significantly less than 2V per cell, then it probably has shorted cells. The only cure for shorted cells is replacement. Sulfated cells are different. They will show a high cell voltage with a small charging current. If you charge them VERY slowly, they are often recoverable. An appropriate charging current would be about 0.1% of it's amp-hour rating. Expect this to take a week or 2 to work, if it is going to work at all. Trying to recover a sulfated cell faster by charging it faster only reduces your chances of success. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- A shorted cell is what I was expecting and your description confirm that. I finally went back to charging 12V across 12 V and the voltag after 12 hours never came up over 6.5V so it appears as if there is shorting problem rather than sulfation. I assume there are 6 2V cell per SLA battery, so it appears I have 3 shorted cells per in eac battery. The BatteryMinder desulfator I have won't commence its desulfatio pulsing till the voltage comes up, so I was only able to perfor desulfation when the two batteries were series. If the low persiste voltage could have been a sulfation sympton, I might have tricked th BatteryMinder into thinking I had a fully charged battery by placing resistor in series with the circuit. Thanks for the confirmation, the batteries were almost 4 years ol anyway. I'll generally convert my SLA packs to NiMH as they nee replacement -- meb |
#6
|
|||
|
|||
Lead acid battery desulfonation
On Mon, 18 Jul 2005 14:35:18 +1000 meb
wrote: A shorted cell is what I was expecting and your description confirms that. I finally went back to charging 12V across 12 V and the voltage after 12 hours never came up over 6.5V so it appears as if there is a shorting problem rather than sulfation. I assume there are 6 2V cells per SLA battery, so it appears I have 3 shorted cells per in each battery. Is there any way to replace individual cells in this battery? This can be done in some SLA assemblies. They are often made up of Gates Cyclon SLA cells. NiMH cells will have significantly lower voltage per cell (~1.5V rather than 2.2V), so they won't make good replacements here. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
#7
|
|||
|
|||
Lead acid battery desulfonation
Jim Adney Wrote: On Mon, 18 Jul 2005 14:35:18 +1000 meb wrote: A shorted cell is what I was expecting and your description confirms that. I finally went back to charging 12V across 12 V and th voltage after 12 hours never came up over 6.5V so it appears as if there is a shorting problem rather than sulfation. I assume there are 6 2 cells per SLA battery, so it appears I have 3 shorted cells per in each battery. Is there any way to replace individual cells in this battery? This can be done in some SLA assemblies. They are often made up of Gates Cyclon SLA cells. NiMH cells will have significantly lower voltage per cell (~1.5V rather than 2.2V), so they won't make good replacements here. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- I wouldn't think individual cell replacement is feasible as th batteries are smooth boxes with terminals. As for the NiMH, you just use more cells -- meb |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Problems with Planet Bike Protege 9.0 - Losing Battery Contact/Resetting | NYC Doc | Techniques | 2 | October 20th 04 11:47 AM |
Lead Battery Seems To Have Expired Suddenly | Chris Hedges | Techniques | 30 | October 5th 04 01:46 AM |
Our Friend Lactic Acid? | Steve Juniper | Techniques | 6 | August 30th 04 01:35 PM |
VistaLite battery question | amirm | Australia | 16 | April 2nd 04 11:09 AM |
Can a dynamo be used to reharge a small lead acid battery? | Clarks | UK | 9 | November 12th 03 08:06 PM |