breaking in new house batteries

[wally12]

I just purchased 4 new 6 volt deep cycle batteries ( lead acid ) for my 5 er. I picked them up a battery retail shop. As I was leaving the employee who handled my purchase told me that I should run the batteries down to 20 % the first couple of cycles to maximise there life. I normally try to pull them down to no more then 50 %.  What are your thoughts ????

 

[rvpuller]

Never heard of anyone doing that, every time you take them down that low it's one less discharge cycle they have left in them.

Denny

 

[Ned]

Bad advice, no need to cycle the batteries beyond their normal use.  50% is the recommended minimum discharge to maximize the number of cycles and battery life.

 

[Gary RV_Wizard]

Yeap - just use them normally.  Lead-acid batteries don't have a memory and don't need a break in.

 

[denmarc]

Yeap - just use them normally.  Lead-acid batteries don't have a memory and don't need a break in.

Is there another type of battery that does have a memory?  Seems like I have heard something similar stated to the OP myself.  But I can't remember pertaining to what kind of battery.  I might even be thinking of small NiCad batteries for cordless phones or something like that.

 

[captsteve]

Lithium ion batteries develop a memory.

 

[Gary RV_Wizard]

Nicad is known for having a "memory". NiMH and Lion batteries generally do NOT exhibit this problem, nor does good old lead-acid or any of its variants.  To the best of my knowledge, only Nicad has the problem, and then only under certain conditions. It was nowhere near as pervasive as pundits would have us believe.

 

[captsteve]

My bad, I got my cells confused (brain that is.) Was thinking NiCad...

 

[Ned]

Lithium ion batteries develop a memory.

Not true, but Nickel-Cadmium batteries do.  The have been mostly replaced with Li-ion or Nickel-Metal-Hydride batteries.

I see Gary and his fast fingers have said the same thing.

 

[Great Horned Owl]

Yeap - just use them normally.  Lead-acid batteries don't have a memory and don't need a break in.

That may not be quite accurate. In the care & maintenance section from US Battery "New deep cycle batteries need to be cycled several times before reaching full capacity (50 - 125 cycles, depending on type). Capacity will be limited during this period." See http://www.usbattery.com/usb_care_maint.html

Joel

 

[Just Lou]

[quote author=Great Horned Owl ]
That may not be quite accurate. In the care & maintenance section from US Battery "New deep cycle batteries need to be cycled several times before reaching full capacity (50 - 125 cycles, depending on type).
[/quote]

The slight capacity increase after a few cycles may be a fact, but I don't think they are actually advocating a special sequence of repeated charge/discharge cycles to reach that point.  Normal cycling, in your regular usage pattern, should accomplish the objective if it's actually going to happen.

 

[Gary RV_Wizard]

Thanks for the tip and the link, Joel. That's a new one on me!

Frankly I'm a bit skeptical and wonder if its just a paper means of deflecting early complaints about capacity. Because by the time you get 125 cycles on a battery that probably has a cycle life in the 300-600 range, they are going to start telling you it is aging and has lost some of its initial capacity.

 

[John From Detroit]

Is there another type of battery that does have a memory?  Seems like I have heard something similar stated to the OP myself.  But I can't remember pertaining to what kind of battery.  I might even be thinking of small NiCad batteries for cordless phones or something like that.

The answer is both yes and no..

NiCad memory is mostly a myth.. IN some specific installations where the battery is discharged to the exact same level and recharged to the exact same level over and over and over and over and over again.. NiCads will develop memory.  About the only place this happens is a satellite in orbit which has teh exact same exposure to the sun every orbit.

In human use, this is impossible to acheive outside a lab.

There is another phenomon however which people mis-ID as memory, I won't go into details but it is not the same thing

LiOn'.. I've never heard of Memory with LiOn, but I don't discount the posibility if you take note of the "Satallite in orbit" comment above.

In practice discharging a battery to EXACTLY the same point over and a over and a over again.. Is not possible in human use.  Only automated use like the orbit.  And even then it takes hundreds of orbits.

 

[denmarc]

In my opinion, the jury is still out on this one.

Pertaining to both NiCad and LiIon, I hear it both ways.  Too many alternatives.  Who is right?

 

[Great Horned Owl]

Before retiring, I was an electronics engineer in the medical device industry. For 15 years, I was involved in the design of portable defibrillators, pacemakers, & cardiac monitors. Battery performance was a big concern, and we did extensive testing of nicads, nimh, and several different lithium chemistries. Battery memory is indeed, a myth.

Joel

 

[denmarc]

Good to know Joel.  My sis-in-law is a RN on the recovery floor at the heart center in the local hospital.  I was going to inquire to her.  Knowing she wouldn't know who/where to ask pertaining to my question, your answer is much easier.

 

[John From Detroit]

Though it appears we agree that memory is a myth.

Batteries do age however, and as they do so they loose capacity.

Plus with Nicads, often the metal is not re-deposited on the shell exactly as it came off, this leads to "Threads" of metal running through the battery, Eventually these short out.

Most of the "Memory Fix" schemes I have read, are about blowing away these threads, Not a thing to do with memory.

 

[denmarc]

Though it appears we agree that memory is a myth.

Batteries do age however, and as they do so they loose capacity.

Plus with Nicads, often the metal is not redeposited on the shell exactly as it came off, this leads to "Threads" of metal running through the battery, Eventually these short out.

Most of the "Memory Fix" schemes I have read, are about blowing away these threads, Not a thing to do with memory.

In other words, disregard what is usually included as instructions for an item using a NiCad battery as proper maintenance?  If so, what were your findings for proper maintenance for said batteries and the like?

 

[Ned]

NiCd batteries do have memory, it's certainly not a myth.  If a NiCd battery is consistently subject to shallow discharge/charge cycles, eventually it will not be able to supply full power for much longer than the shallow discharge level.  Several full discharge/charge cycles may restore the full capacity of the battery.  Newer battery designs, like Lithium-Ion and NMH are not subject to this problem.

 

[denmarc]

NiCd batteries do have memory, it's certainly not a myth.  If a NiCad battery is consistently subject to shallow discharge/charge cycles, eventually it will not be able to supply full power for much longer than the shallow discharge level.  Several full discharge/charge cycles may restore the full capacity of the battery.  Newer battery designs, like Lithium-Ion and NMH are not subject to this problem.

Thanks Ned.  We have a couple NiCad operated items around the stick house. I am thinking a couple in the TT also.  I was always taught to deplete the the item of voltage when new, and then charge it up fully.  This protocol would "teach" the battery what is expected of it.