[PSUBS-MAILIST] venting batteries

Tue Mar 11 18:01:29 EDT 2014

Hank,

Some types of lithium ion batteries presently available might  be just as 
economical as AGMs, etc. when you consider the number of recharging  cycles - 
cost twice as much, but last more than twice as long.  Several  subs are 
presently operating with them.

Here's as good a place as any to start if you want to  investigate those 
options.  http://en.wikipedia.org/wiki/Lithium-ion_battery  
I've pasted a key paragraph below.  When I last looked  into it I was most 
in favor of LFP.  

Chemistry, performance, cost and safety characteristics vary across LIB  
types. Handheld electronics mostly use LIBs based on _lithium cobalt  oxide_ 
(http://en.wikipedia.org/wiki/Lithium_cobalt_oxide)  (LiCoO
2),  which offers high energy density, but presents safety risks, 
especially when  damaged. _Lithium iron  phosphate_ 
(http://en.wikipedia.org/wiki/Lithium_iron_phosphate)  (LFP), _lithium manganese  oxide_ 
(http://en.wikipedia.org/wiki/Lithium-manganese_battery)  (LMO) and lithium nickel manganese 
cobalt oxide (NMC) offer lower  energy density, but longer lives and inherent 
safety. Such batteries are widely  used for electric tools, medical equipment 
and other roles. NMC in particular is  a leading contender for automotive 
applications. Lithium nickel cobalt aluminum  oxide (NCA) and _lithium 
titanate_ (http://en.wikipedia.org/wiki/Lithium_titanate)  (LTO)  are specialty 
designs aimed at particular niche roles.

Jim

In a message dated 3/11/2014 4:39:14 P.M. Central Daylight Time,  
hanker_20032000 at yahoo.ca writes:

Joe,
It may be moot for you, you will be able to buy sulfur ion  batteries.  I 
am just looking to save some money in hopes the new  batteries are on the 
market next year.  If it is true about the sulfur  batteries our range will 
increase by six times.
Hank

On Tuesday, March 11, 2014 3:27:57 PM,  Joe Perkel <josephperkel at yahoo.com> 
wrote:

So the question in my mind then with regard to George's scheme for  venting 
the pods as per plans,.. Is it adequate as is? 

My thoughts have always been to supplement that plan with ignition proof  
forced ventilation.

Joe

On Mar 11, 2014, at 5:06 PM, hank pronk <_hanker_20032000 at yahoo.ca_ 
(mailto:hanker_20032000 at yahoo.ca) >  wrote:

Vance,
The nice thing about hydrogen is how light it is, with my idea  the 
hydrogen if leaked would simply drift to the hatch and out.  The  floor is not air 
tight so the Hydrogen can escape if the vent system has a  leak.  As with 
the original system, the battery vent system can be  pressure tested prior to 
charging.  Just sayin 
Hank

On Tuesday, March 11, 2014 2:50:55 PM,  Vance Bradley <_VBra676539 at AOL.com_ 
(mailto:VBra676539 at AOL.com) > wrote:

Hank,
Any low cost hydrogen vent system will leak. I've seen perfectly tight  
systems tested with nitrogen that leak like sieves when charged with dive  gas. 
And if you have a leaky system then you have no system. Even a little  
hydrogen can ruin your whole day.
Vance

Sent from my iPhone

On Mar 11, 2014, at 4:03 PM, hank pronk <_hanker_20032000 at yahoo.ca_ 
(mailto:hanker_20032000 at yahoo.ca) >  wrote:

Vance,
I get that for sure, it just seems logical to vent the battery  directly.  
What am I missing here?  Why vent the  Hydrogen into  a space then vent the 
space, makes no  sense.
Hank

On Tuesday, March 11, 2014 10:19:53  AM, Vance Bradley 
<_VBra676539 at AOL.com_ (mailto:VBra676539 at AOL.com) > wrote:

Hank,
The vent system should be used for half an hour prior to charging to  clear 
the keel, then throughout the charge and finally for another half to  one 
hour afterward. What the maintenance log does not say is that somebody  
forgot to turn on the LP supply air during a charge. It happened once on  Delta, 
too. Bang! Her deck plates all have a slight upward bulge as a  result. Oops.
Vance

Sent from my iPhone

On Mar 11, 2014, at 8:43 AM, hank pronk <_hanker_20032000 at yahoo.ca_ 
(mailto:hanker_20032000 at yahoo.ca) >  wrote:

Steve, 
I am thinking interior of the hull.  Gamma has interior  batteries sealed 
in a box.  There is an air system to purge the box  after charging.  When I 
was reading the daily service reports, I  read about an instance where the 
box had an explosion due to a faulty  cable connection.  I was thinking of 
going one step further and  drilling in vent tubes in the sealed caps to carry 
the hydrogen  away.  I am not sure if this is a good idea or not, seems 
simple  and effective. 
Hank

On Tuesday, March 11, 2014 6:09:52  AM, Steve McQueen 
<_psub101 at indy.rr.com_ (mailto:psub101 at indy.rr.com) >  wrote:

Hank, in this scenario are the batteries interior to the hull or  exterior 
in pods?

Steve

On Mon, Mar 10, 2014 at 5:09 PM,  hank pronk <_hanker_20032000 at yahoo.ca_ 
(mailto:hanker_20032000 at yahoo.ca) >  wrote:

Does anyone have an opinion on drilling in vent tubes  to  each battery, 
and seal off the original vent holes.   Run  the vent tubes to a manifold and 
purg.  Keep the vent tubes going  up hill all the way.
Hank

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