post-charge voltage of SLA batteries

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   For the folk using 12V SLAs ....

Just wondering what voltage people are seeing after their normal charge cycle.

I have several SLAs :_

1 x 7Ah Ritar bought new last year - always charged soon after use and gets maintenance charge every few weeks during winter.

13.19V

1 x 7Ah Powersonic I got given - unused at the time, but likely had sat on a shelf for some months without maintenance charge.

13.00V

1 x 7Ah Yucel that I bought new 4 years ago - not so well maintained - still works ....

12.10V

2 x Yuasa 24Ah mobility-scooter type .... 1 was unused, 1 used - both had a few months without maintenance charge before I was given em.

12.76V and 12.73V respectively

1 x 24Ah Ritar bought unused but prob not maintained for some months before it came to me (fitted to a jump-start case) - lightly used - always maintained.

13.02V

These days I use a Lidl £12.99 smart charger for all the above - set to charge at 14.4V (it also has a 14.7V setting).

These voltages are measured with a cheapie little digital meter about 10-20 mins after charge has completed.

What do other folk see ? ... and  please  indicate what kind of charger/regime do you use ?
Reason for asking is - I wonder to what extent the post-charge voltage indicates the real-world battery condition.

Edited by slaz - 19 March 2014 at 11:11am

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slaz Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 November 2009 Location: London E2 Status: Offline Points: 2713	Post Options Post Reply Quote slaz Report Post Thanks(0) Quote Reply Topic: post-charge voltage of SLA batteries Posted: 19 March 2014 at 10:38am
	For the folk using 12V SLAs .... Just wondering what voltage people are seeing after their normal charge cycle. I have several SLAs :_ 1 x 7Ah Ritar bought new last year - always charged soon after use and gets maintenance charge every few weeks during winter. 13.19V 1 x 7Ah Powersonic I got given - unused at the time, but likely had sat on a shelf for some months without maintenance charge. 13.00V 1 x 7Ah Yucel that I bought new 4 years ago - not so well maintained - still works .... 12.10V 2 x Yuasa 24Ah mobility-scooter type .... 1 was unused, 1 used - both had a few months without maintenance charge before I was given em. 12.76V and 12.73V respectively 1 x 24Ah Ritar bought unused but prob not maintained for some months before it came to me (fitted to a jump-start case) - lightly used - always maintained. 13.02V These days I use a Lidl £12.99 smart charger for all the above - set to charge at 14.4V (it also has a 14.7V setting). These voltages are measured with a cheapie little digital meter about 10-20 mins after charge has completed. What do other folk see ? ... and please indicate what kind of charger/regime do you use ? Reason for asking is - I wonder to what extent the post-charge voltage indicates the real-world battery condition. Edited by slaz - 19 March 2014 at 11:11am
	REMEMBER....POLITICIANS AND DIAPERS SHOULD BE CHANGED OFTEN AND FOR THE SAME REASON

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 25 March 2014 at 1:55pm
	A fully charged 6 cell lead-acid battery in good condition should read about 13 - 13.2v immediately after charge and for some time if nothing is connected, and should drop to 12.8v under moderate load. I usually assume the range from charged to discharged is 1 volt, from 12.8v down to 11.8v, with each 0.1v drop representing 10% capacity used. I try not to go below 12.0v in normal use though. That Yucel 7Ah definitely has a problem, and should read higher than that. I bet if you put a load on it like a 12 ohm power resistor (for a 1A current) it drops right down to about 11.0v, yes? According to some fearless geeks wearing rubber gloves on Youtube, it is possible to top up even a gel battery with distilled water, and sometimes this recovers lost capacity. It might also be worth trying a desulphation device to clean the plates.
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

SamV Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 21 October 2008 Location: London Status: Offline Points: 8711	Post Options Post Reply Quote SamV Report Post Thanks(0) Quote Reply Posted: 31 March 2014 at 4:21pm
	Most of my 12v batteries read 13.4 to 13.6v after charge. In use they hold steady at 13.2-4 until they drop to 12.8 after an hour, and then stay there and gradually go down to 11v when fully discharged about 8-24hr hours later. Bearing in mind they are 120ah deep cycle running bigger systems.