BAT­TERY BA­SICS

Part 2 of Amer­i­can Sur­vival Guide’s ex­clu­sive two-part guide to bat­ter­ies

American Survival Guide - - TABLE OF CONTENTS - By Jim Jef­fries

In part 1 of our bat­tery se­ries (which ap­peared in our Jan­uary is­sue), we took a brief look at the 200-plus-year his­tory of bat­ter­ies and dis­cussed some of the dif­fer­ent bat­tery chemistries and how they de­ter­mine the volt­age and power char­ac­ter­is­tics of voltaic cells. In part 2, we will look a lit­tle deeper into both sin­gle-use ("pri­mary") and re­us­able ("sec­ondary") bat­tery types we com­monly use in our gear. We also test sev­eral bat­ter­ies from dif­fer­ent man­u­fac­tur­ers to see which ones are the best choices to in­clude in your pre­pared­ness and sur­vival sup­ply locker. AA cells make up 50 per­cent of the roughly three bil­lion al­ka­line bat­ter­ies sold in the United States an­nu­ally, fol­lowed by AAA at 30 per­cent. C, D and 9-volt bat­ter­ies make up the rest. A look at the bat­tery shelves in a re­tail out­let sup­ports that break­down, but it also shows a fairly wide range in prices among brands. A cou­ple of name brands are very pop­u­lar and are among the most ex­pen­sive bat­ter­ies to buy. One would think that premium pric­ing would im­ply premium prod­ucts that surely must be bet­ter than the less-ex­pen­sive va­ri­eties ... but is that the case? The only way to find out would be to test them in a con­trolled ex­per­i­ment. As it turns out, there is not much dif­fer­ence be­tween the premium-priced bat­ter­ies and the less-ex­pen­sive brands. How­ever, there is a sig­nif­i­cant dif­fer­ence in cost per hour of op­er­a­tion (see page 46 for our test re­sults). Mar­ket­ing adds to the price of bat­ter­ies, and the two lead­ing al­ka­line bat­tery man­u­fac­tur­ers spend a boat­load on ad­ver­tis­ing. This cost is passed on to the con­sumer. So, just be­cause a bat­tery costs more at check­out doesn’t mean it will last any longer in your de­vice. In fact, the “longer-last­ing” claim does not re­fer to usage at all; rather, it refers to the bat­tery’s shelf life when stored prop­erly.

EF­FECTS OF TEM­PER­A­TURE ON BAT­TER­IES

Al­ka­line bat­ter­ies ex­hibit very lit­tle power loss when stored in a cool, dry en­vi­ron­ment (68 to 78 de­grees [F]). Typ­i­cally, al­ka­line bat­ter­ies have a shelf life of five to 10 years and will re­tain at least 80 per­cent of their orig­i­nal charge un­der the right con­di­tions. El­e­vated tem­per­a­tures will ac­cel­er­ate loss, but it is not nec­es­sary to store bat­ter­ies in a re­frig­er­a­tor un­less am­bi­ent tem­per­a­tures are ex­ces­sive. The suggested tem­per­a­ture range for use of al­ka­line bat­ter­ies is 0 to 131 de­grees (F), mak­ing them suitable for year-round use in most en­vi­ron­ments. If you fre­quent more-ex­treme con­di­tions—arc­tic cold or Death Val­ley hot—lithium bat­ter­ies are bet­ter bets. The En­er­gizer Ul­ti­mate Lithium AA bat­tery, for ex­am­ple, has a rec­om­mended tem­per­a­ture range of -40 to 140 de­grees (F). Be­sides the much broader tem­per­a­ture range, the Ul­ti­mate Lithium of­fers a cou­ple of other ben­e­fits over al­ka­line cells: Shelf life at room tem­per­a­ture is up to 20 years—dou­ble that of most al­ka­line cells; and the lithium bat­tery has con­sid­er­ably more en­ergy that re­mains more con­sis­tent (less volt­age drop) un­der heavy-cur­rent de­mand. As a re­sult, your Aa-pow­ered flash­light can stay nice and bright up to the point of bat­tery ex­haus­tion!

LITHIUM VS. AL­KA­LINE

Although the En­er­gizer Ul­ti­mate Lithium AA costs more than al­ka­line bat­ter­ies, the ad­di­tional en­ergy it packs brings its cost per hour of op­er­a­tion to about the same. Be­sides the longer op­er­at­ing time, the ex­tended tem­per­a­ture range per­for­mance makes the En­er­gizer Ul­ti­mate Lithium an ex­cel­lent choice for gear that is stored in­side a ve­hi­cle, sum­mer or win­ter, where it will be ex­posed to ex­treme tem­per­a­ture swings. Sev­eral bat­ter­ies that find use in our gear are only avail­able as lithium. The CR123 (or 123A), CR2 and the CR2032 coin cells are com­mon ex­am­ples. These bat­ter­ies are often cho­sen by man­u­fac­tur­ers for night vi­sion de­vices, il­lu­mi­nated ret­i­cles in ri­fle scopes, laser range fin­ders, tac­ti­cal flash­lights and many more gad­gets due to the high en­ergy den­sity-to-size ra­tio lithium cells pro­vide.

BEN­E­FITS OF RECHARGEABLES

All the al­ka­line and lithium bat­ter­ies dis­cussed so far are “pri­mary” cells—sin­gle-use, dis­pos­able bat­ter­ies—and can­not be recharged to any use­ful ex­tent. “Sec­ondary” bat­ter­ies are re­us­able and much more cost ef­fec­tive, es­pe­cially if you tend to go through a lot of bat­ter­ies. They do, how­ever, re­quire that you have the means to charge them. NIMH bat­ter­ies. The most com­mon recharge­able dry cell bat­tery for our por­ta­ble gear is the

MUCH OF OUR GEAR RE­QUIRES ONLY THE MIND, EYE AND HAND OF THE OP­ER­A­TOR TO USE AND MAIN­TAIN—AS IT SHOULD BE. BUT SOME OF OUR GEAR DE­PENDS ON SOME­THING OFTEN IN SHORT SUP­PLY WHEN AN EMER­GENCY ARISES: ELEC­TRIC­ITY.

nickel-metal hy­dride, or NIMH. Avail­able in sizes from AAA to D cell and 9 volt, NIMH bat­ter­ies are much more ca­pa­ble than the older nickel-cad­mium (Ni­cad) bat­ter­ies, and they don’t ex­hibit the “mem­ory” phe­nom­e­non that plagues Ni­cad bat­ter­ies. While it might be best to let them com­pletely dis­charge be­fore fully recharg­ing them, NIMH cells can be re­moved and charged at any state of charge ("SOC") without con­cern of re­duced ca­pac­ity. Prop­erly charged and cared for, recharge­able bat­ter­ies can go through hun­dreds of charge cy­cles (charge-dis­charge) be­fore they even­tu­ally start los­ing their ca­pac­ity. They can also be dis­charged quite deeply. NIMH cells, how­ever, do not store well for long pe­ri­ods. A fully charged NIMH cell will lose 10 to 15 per­cent of its charge within the first 24 hours and then about 10 per­cent per month in stor­age. It is rec­om­mended to top off the charge be­fore us­ing the bat­tery and fully charge it ap­prox­i­mately ev­ery six months in stor­age. NIMH bat­ter­ies should be stored at room tem­per­a­ture and typ­i­cally have a usage tem­per­a­ture range of 14 to 122 de­grees (F). How­ever, they should only be charged when the bat­tery tem­per­a­ture is be­tween 32 and 104 de­grees (F). Recharge­able bat­ter­ies brought in from ex­treme cold must be al­lowed to reach room tem­per­a­ture be­fore charg­ing. As with al­ka­line bat­ter­ies, it is im­por­tant to make sure all recharge­able bat­ter­ies used in a de­vice are of the same brand, ca­pac­ity and state of charge. Mix­ing bat­ter­ies of dif­fer­ent types, ca­pac­ity, age or charge level can per­ma­nently dam­age or di­min­ish the charge ca­pac­ity of NIMH cells and can cause them to over­heat or rup­ture—which could also dam­age your de­vice. NIMH bat­ter­ies are avail­able in a va­ri­ety of ca­pac­i­ties (even from the same man­u­fac­turer). Aa­sized NIMH bat­ter­ies can range from 1,350 mil­liamp hour (mah) to 2,500 mah, so it’s a good idea to read the bat­tery la­bels to en­sure they are all the same ca­pac­ity be­fore charg­ing or us­ing them. Lead acid deep-cy­cle bat­ter­ies. The big, heavy, lead acid deep-cy­cle bat­ter­ies used for boat­ing or recre­ational ve­hi­cle ap­pli­ca­tions are ex­cel­lent off-grid power sources for homestead or bug-out lo­ca­tions. While not very por­ta­ble, they can pro­vide a long-last­ing en­ergy reser­voir for recharg­ing the smaller bat­ter­ies we use in our de­vices. Kept full by util­ity power or a wind or so­lar charg­ing sys­tem, they are safer and more con­ve­nient al­ter­na­tives to gaso­line-pow­ered gen­er­a­tors. Au­to­mo­tive-start­ing bat­ter­ies are not well-suited for this pur­pose, be­cause they are de­signed to pro­vide a brief high-cur­rent burst to start an en­gine. Long, low-cur­rent loads can quickly dis­charge them. SLA bat­ter­ies. Smaller, sealed lead acid (SLA) bat­ter­ies are a good al­ter­na­tive to the larger, wet-cell deep-cy­cle bat­ter­ies. Their lighter weight and spill-proof de­sign al­low them to be trans­ported eas­ily. LIFEPO4 bat­ter­ies. How­ever, if porta­bil­ity is a pri­mary con­cern, con­sider the newer lithium iron phos­phate (LIFEPO4) bat­ter­ies. Often called “lithium phos­phate,” these bat­ter­ies are less toxic and safer than other lithium ion chemistries, and they can be dis­charged very deeply, up to 90 per­cent, without any dam­age to the cells. Com­pared to lead acid bat­ter­ies, which should not be dis­charged be­low 50 per­cent, lithium phos­phate bat­ter­ies of the same rated ca­pac­ity can pro­vide nearly twice the use­able power at half the weight. Yes, they are con­sid­er­ably more ex­pen­sive to buy (how much is your back worth?), but they can sup­ply so much more power and un­dergo many more cy­cles than lead acid bat­ter­ies. They are a bar­gain in the long run.

RECHARG­ING THESE BAT­TER­IES

All recharge­able bat­ter­ies ben­e­fit from cy­cling (charge-dis­charge cy­cles), and they all dis­play some level of self-dis­charge. Long-term stor­age will re­quire an oc­ca­sional top­ping charge to keep them “healthy,” but the big­gest killer of sec­ondary bat­ter­ies is over­charg­ing. Once a bat­tery is com­pletely charged, con­tin­ued charge cur­rent will be con­verted to heat and can cause the elec­trolyte to dry out (among other is­sues). Lead acid bat­ter­ies held at a high charg­ing volt­age will pro­duce ex­ces­sive gas due to elec­trol­y­sis (split­ting the wa­ter in the elec­trolyte to hy­dro­gen and oxy­gen), and even­tu­ally, the elec­trolyte needs to be re­plen­ished by adding dis­tilled wa­ter. Main­te­nance-free wet-cell bat­ter­ies have cov­ers over the cells that are de­signed to re­com­bine the gasses to re­duce the loss of wa­ter, but they can­not re­com­bine enough to keep the so­lu­tion in the cells at the ap­pro­pri­ate level over time. Re­moval of the cov­ers to in­spect the elec­trolyte level could be dif­fi­cult. But this should be done pe­ri­od­i­cally and care­fully, and dis­tilled wa­ter should be added as nec­es­sary if the bat­tery is con­nected to a charger con­tin­u­ously.

PROP­ERLY CHARGED AND CARED FOR, RECHARGE­ABLE BAT­TER­IES CAN GO THROUGH HUN­DREDS OF CHARGE CY­CLES (CHARGE-DIS­CHARGE) BE­FORE THEY EVEN­TU­ALLY START LOS­ING THEIR CA­PAC­ITY.

Charg­ing sec­ondary bat­ter­ies should be done only with a charger de­signed for the volt­age, size and chem­istry of the bat­tery to be charged. The com­pa­nies that man­u­fac­ture bat­ter­ies for the por­ta­ble use (AA through D cell sizes) mar­ket will often in­clude wall or other charg­ers for their bat­ter­ies. Smart charg­ers. While these man­u­fac­turer-pro­vided charg­ers might seem to work ac­cept­ably, the best cy­cle life usu­ally comes when smart charg­ers are used. Smart charg­ers mon­i­tor each cell in­di­vid­u­ally and can ad­just for op­ti­mal charge rate. Ad­di­tion­ally, they are less likely to over­charge or over­heat the bat­tery; and some will even re­con­di­tion bat­ter­ies that are show­ing di­min­ished ca­pac­ity. Wet-cell bat­ter­ies usu­ally re­quire more-sub­stan­tial charg­ers—es­pe­cially the high amp hour-ca­pac­ity deep cy­cles. Again, smart charg­ers can tai­lor the charge rate to give the deep­est charge without the worry of over­charg­ing. Charg­ers that are de­signed only to main­tain a full charge are often un­der­pow­ered and might never be able to fully recharge a de­pleted bat­tery. Off-grid power gen­er­a­tion so­lu­tions, such as so­lar or wind, are the best bet for any con­di­tion. So­lar or wind charge con­trollers can di­rectly main­tain 12 volt recharge­able bat­ter­ies, which can then be used to charge por­ta­ble bat­ter­ies. So, there isn’t any rea­son to be without bat­tery power … ever.

... THE “LONGER-LAST­ING” CLAIM DOES NOT RE­FER TO USAGE AT ALL; RATHER, IT REFERS TO THE BAT­TERY’S SHELF LIFE WHEN STORED PROP­ERLY.

Above: Buy­ing bat­ter­ies in large quan­ti­ties can save big bucks.

Right: With all the bat­tery-pow­ered de­vices we de­pend on, con­sider re­duc­ing your ex­penses and stor­age space re­quire­ments by us­ing sec­ondary (recharge­able) bat­ter­ies,

Above: The Garmin etrex Ven­ture HC is a very pop­u­lar hand­held GPS de­vice ... but it’s a bat­tery hog.

Far left: Smart charg­ers mon­i­tor the charg­ing process of each cell in­di­vid­u­ally, en­sur­ing a full charge without harm­ful over­charg­ing.

Above: Mis­sion-crit­i­cal gear needs to work in any en­vi­ron­ment. The last thing you need to worry about is whether your bat­ter­ies can take the heat or the cold. The En­er­gizer Ul­ti­mate Lithium will out­per­form al­ka­line bat­ter­ies in both op­er­a­tional time and tem­per­a­ture ex­tremes.

Near left: All these bat­ter­ies will fit in the same de­vice, but they are in­com­pat­i­ble with each other. Never mix bat­tery brands, types, chemistries or ca­pac­i­ties.

The Ren­ogy Voy­ager So­lar Charge Con­troller can han­dle 20 amps of so­lar panel in­put and can charge sev­eral dif­fer­ent bat­tery chemistries, in­clud­ing LIFEPO4. (www.ren­ogy.com)

Be­low: Smart charg­ers that come with 12 volt au­to­mo­tive power con­nec­tors al­low you to charge bat­ter­ies on the move and can be con­nected to so­lar charg­ing sys­tems for grid-free op­er­a­tion.

The NOCO Ge­nius Smart Charger se­ries comes highly rec­om­mended and is very af­ford­able. (https:// No.co)

Above: LIFEPO4 (lithium iron phos­phate) bat­ter­ies pro­vide nearly twice the power as sealed lead acid (SLA) bat­ter­ies of the same amp-hour rat­ing—and they weigh half as much.

Left: Plas­tic en­clo­sures of­fer im­pact pro­tec­tion and will con­tain any spills or leak­age when ser­vic­ing lead acid bat­ter­ies. The top of the en­clo­sure cov­ers the ter­mi­nals, re­duc­ing the chance of short cir­cuits across the posts.

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