Hi David,
Anything would be preferable to AGM.
Most of the battery savvy folks use the large telecom batteries that have a clear case and space between the lead plates and cell wall. They have the additional advantage of an SG smapling port that can be used to bubble the cells with low pressure air. This will remix the electrolyte in the event it becomes stratified due to non-use.
Another advantage to these large 2 volt cells are the reduced self discharge rates. It seems over time multi-cell batteries wind up with partially conductive cell walls that allow increased self discharge amperage.
The only thing AGM batteries are good for is providing power in a Zero-G environment such as space exploration.
Some applications trade longevity for convenience such as packaged units like emergency lighting or UPS. But the owners have to be prepared for battery replacement every few years.
Lead-Acid flooded cell batteries will last 20-30 years if they are maintained properly and not exposed to high heat conditions.
Don
--- In electricboats@yahoogroups.com, "davidhughes_casaba" <davidhughes_casaba@...> wrote:
>
> I remember the sparrow and never knew what happened. Interesting.
>
> I must admit, this is the first I have heard bad things about AGMs. What do you recommend flooded wet lead acids like Trojan or some other technology?
>
> Thanks
> Dave
>
> --- In electricboats@yahoogroups.com, "desulfator" <desulfator@> wrote:
> >
> >
> > It has been my experience that Optima and other lead acid batteries with "Spiral Wound Cells" are the worst AGM battery on the market.
> >
> > It was the biggest coffin nail in the Corbin Motors Sparrow downfall when Corbin was stuck with trailer loads of failed Optima batteries. Optima provided no relief and the company shortly went into bankruptcy.
> >
> > Corbin shares part of the blame for squeezing batteries into battery boxes with little to no cooling provided. But, that is a common battery powered vehicle engineering mistake that prevails even to the present day in all electric vehicles.
> >
> > http://en.wikipedia.org/wiki/Corbin_Sparrow
> >
> > The spiral wound cell achilles heel is due to heat buildup in the center of the cell. It results in early cell failure due to dehydration from heat buildup, pressure relief valve popping and eventual cell death. Leaking pressure relief valves are common in the AGM battery.
> >
> > In the case of Sparrow, it was excaberated by the use of Zivan (and others) chargers attempting to charge the series connected battery bank of over 100 volts. This is when we first learned of bank cascade failures due to an unbalanced high voltage bank.
> >
> > It is one of the reasons why,
> >
> > 1. I would never recommend AGM batteries
> >
> > 2. I always recommend seperate 12 volt chargers for any bank over 12 volts
> >
> > -
> >
> > So some of the leasons we learned from the Corbin Motors experience are,
> >
> > 1. Never use AGM batteries
> >
> > 2. Have seperate chargers for each battery
> >
> > 3. Desulfate batteries before permanent damage sets in
> >
> > 4. Insure battery boxes are well ventilated or the batteries are water cooled
> >
> > 5. Multiple battery banks should never have the batteries sides touching one another. It forms a large thermal mass that is virtually impossible to cool.
> >
> > 6. Pulse chargers are best
> >
> >
> >
> > --- In electricboats@yahoogroups.com, "davidhughes_casaba" <davidhughes_casaba@> wrote:
> > >
> > > Just currious. I noticed on a random Torqeedo piece of liturature that I came across that Torqeedo recommends Optima Batteries over others. I was currious in what others have found or think when comparing the 2. I do know that Optima does not offer anything larger then Group 31 and that the amp hours for their group 31s are rated lower then Lifeline's. Makes me wounder why Torqeedo aligned themselves with Optima.
> > >
> >
>
No comments:
Post a Comment