PWM frekvensområde for batteri ladning

period=20

Hej Monie

Et batteri skal blot oplades med DC.

Her er mere information:

BATTERY INFORMATION LINKS LIST:

Car and Deep Cycle Battery Frequently Asked Questions (FAQ) 5.1:

EVALUATION OF THE BATTERIES AND CHARGE CONTROLLERS IN SMALL STAND:

Operation and maintenance field experience for off-grid:

-

PWM frekvensen er kun interessant for smps-str=F8mforsyningens design.=20 Smps output er normalt DC.

Fordele ved h=F8jere designfrekvens:

*Trafo fylder mindre *Mindre kondensatorer - men de skal have lav ESR (Low Equivalent Series=20 Resistance)

Fordele ved lavere designfrekvens:

*Mindre HF-st=F8j *Mindre mosfet,transistor-tab *Mindre diode-tab

Se mere her:

mvh/Glenn

Hej Glenn

Mange tak forde du svarede. Jeg vil kigge på de link du henviser til.

MVH Monie

"Glenn Møller-Holst" skrev i en meddelelse news: snipped-for-privacy@x.dk... M> Hvilken frekvens område er bedst til ladning af bly-batteri'er?

Hej Monie

Et batteri skal blot oplades med DC.

Her er mere information:

BATTERY INFORMATION LINKS LIST:

Car and Deep Cycle Battery Frequently Asked Questions (FAQ) 5.1:

EVALUATION OF THE BATTERIES AND CHARGE CONTROLLERS IN SMALL STAND:

Operation and maintenance field experience for off-grid:

-

PWM frekvensen er kun interessant for smps-strømforsyningens design. Smps output er normalt DC.

Fordele ved højere designfrekvens:

*Trafo fylder mindre *Mindre kondensatorer - men de skal have lav ESR (Low Equivalent Series Resistance)

Fordele ved lavere designfrekvens:

*Mindre HF-støj *Mindre mosfet,transistor-tab *Mindre diode-tab

Se mere her:

mvh/Glenn

Du skal vist bruge meget tid på at kigge og lære...! (Udfra dit gæt på ladning med AC)

NB. Overvej at gøre som de fleste andre, og som reglen er: Svar _under_ det du kommenterer, og slet overflødig tekst.

Det plejer du ikke at gøre, nej det kan jeg se.

Kig på

Mvh. Jørgen

Ikke AC men pulserende DC. pulserende DC er en ladeteknik der kan benyttes på NICD batterier så mindskes memoryeffekten.

Jacob

Det lyder ikke rigtigt.

Kilde?

-- Jeg kan virkelig ikke se, hvad det skulle betyde, at forbinde en 0,1 mm X 1 mm tin-fyldt kobberbane i ét apparat med en anden 0,1 mm X 1 mm tinfyldt kobberbane i et andet apparat, via et sølvbelagt 4 mm2 polafhængigt højteknologisk kulfiberinfiltreret kabel til et astronomisk beløb.

Tro flytter ikke bjerge. Tro flytter kroner.

tes=20

Hej Ole

Det har faktisk v=E6ret 2 kontroversielle emner i lang tid og der er=20 tilh=E6ngere i begge lejre vedr. memery-effekt og DC med AC overlejret.

-

Der er delte meninger om "memory"-effekten i NiCd-akkumulatorer eksistere= r:

"memory"-effekten er en myte:

James A. Zaun: NiCd battery "memory" is largely myth.

James A. Zaun: NiCd Batteries do NOT have "memory":

"memory"-effekt eksisterer:

Isidor Buchmann: Memory: Myth or fact?:

2.9) Does the memory effect exist?:

Nyere adresser er m=E5ske her:

-

For NiMH er der m=E5ske f=F8lgende forklaring. Det kan skyldes generelt=20 faldende kapacitet efter 300 ladningscykler (alts=E5 permanent=20 "memory-effekt"):

Choosing a battery that will last

"... Figure 4 examines the NiMH, a battery that offers high energy density at =

low cost. We observe good performance at first but past the 300-cycle=20 mark, the performance starts to drift downwards rapidly. One can observe =

the swift increase in internal resistance and self-discharge after cycle =

count 700. =2E.."

"... How much battery maintenance is needed? The NiMH and NiCd are considered high maintenance batteries that require =

regular discharge cycles to prevent memory. Although the NiMH was=20 originally advertised as memory-free, both NiCd and NiMH are affected=20 similarly by memory. =2E.."

-

Teknikken med DC overlejret med AC hedder "reflekslader", "Negative=20 Pulse Charge" eller "Burp" Charging:

Negative Pulse Charge, or "Burp" Charging: Fact or Fiction?:

Hovedadresse:

En god ladestrategi er m=E5ske her: Elektor 6/1993, side 26-30, Manfred Greve, ICS-1700-reflexlader.

Der findes f=F8lgede ladekredse; NiCd og NiMH: ICS1700A (dV/dt) & ICS1702 (dV/dt og/eller dT/dt), Lithium: ICS1733, bly: ICS1735:

;.

Produktguide:

;: Citat side 1 "...selectable charge rates: 15 min to 4 Hr for NiCd, 35 min=

to 4 Hr for NiMH...Pulse charge conditioning and precision charge control eliminates "memory" effects and "capacity fade". ...dramatically extended battery life: twice the life compared to -dV and peak overcharge detect methods, up to ten (10) times the life compared to "brute-force" time/temperature cut-off and constant trickle overcharge methods. ...Customer tested to over 2800 charge/discharge cycles...Used by NASA in space shuttle and space station applications: space suit helmet light...space propulsion units...".

ICS1702 datablad:

;.

Firmaet bag ICS1700 er oprindeligt Integrated Circuit Systems:

;

Flere referencer om elementer og akkumulatorer:

For en del =E5r siden (1985) skrev Rod Cooper nogle artikler om NiCd akkumulatorer ve & vel. Han har yderligere referencer ang=E5ende akkumulatorer. Se i: Electronics World & Wireless World 1985. Nr 5. Nr

6 side 60-63 "Avoiding failures of sealed NiCd cells". Nr 7 side 32-36 "Recharging system for NiCd cells". Nr 8 side 73 "NiCd cells - part 4". Der er desv=E6rre en del fejl i hans diagram til opladesystemet. Jeg har ikke lige papirene ved h=E5nden, s=E5 de kan ikke blive remset op. Han argumenterer for DC ladning med overlejret 50 Hz AC, s=E5 der oplades ladning ca. 80% og aflades 20% i en periode, men dette 80/20 forhold skulle ikke v=E6re s=E5 kritisk. Denne ladetype har 2 m=E5l; h=E6mme dend= rit dannelse (intern celle kortslutning) og lavere indre modstand ved afladning. Desuden m=E5 der ikke lades p=E5 NiCd, NiMH, n=E5r celletemperaturen er udenfor intervallet +5...+40 grader C.

Funkschau 12/1998: side 81-84, Helmuth Lemme, Professionelle Akku-Ladetechnik, stikord:"reflexladen, VDX-verfahren, NiCd, Li-ion, Alkali-Mangan, Bleiakku".

mvh/Glenn

-- Anders Henriksen - born without teeth supermule [at] lite [dot] dk

To alcohol! The cause of - and solution to - all of life's problems!

Her er lidt om PWM-ladning af blybatterier. Glenn har jo skrevet om nikkel-baserede batterier.

Om PWM-ladning af blyakkumulatorer til solceller og ladeeffektivitet (fabrikant):

Det fremgår at "PWM pulse charging can deter the formation of sulfate deposits", hvilket jeg mener at have læst på en uafhængig side, men den kan jeg selvfølgelig ikke finde lige nu.

Her nævnes PWM-ladning af blyakkumulatorer kort:

Der er blandt eksperter ikke megen enighed om PWM-ladningens goder, men blandt RC-folk (nikkelbatterier) er det vist nok det helt store hit, gerne med en negativ puls for hver 100, eller så. Det skulle både øge den elektromotoriske kraft og sænke den indre modstand.

--
Anders Henriksen - born without teeth
supermule [at] lite [dot] dk

To alcohol! The cause of - and solution to - all of life's problems!

Anders Henriksen wrote: =2E..

en den kan

Hej Anders

Der er desv=E6rre, s=E5vidt jeg kan se, blandet 3 ting sammen:

1) PWM er en teknik, der anvendes i:

PWM st=E5r for "Pulse Width Modulation", hvilket overs=E6ttes til=20 Pulsbreddemodulation.

Negative Pulse Charge, or "Burp" Charging: Fact or Fiction?:

2) De teknikker der anvendes ved NiCd og NiMH kaldes "reflekslader",=20 "Negative Pulse Charge" eller "Burp" Charging.

If=F8lge denne kilde er teknikken aflivet som v=E6rende en fordel:

Negative Pulse Charge, or "Burp" Charging: Fact or Fiction?:

Citat: "...It has never been demonstrated to have any advantage over=20 conventional charging, either on charge efficiency, the performance or=20 the life of the battery..."

3) Antisulfateringspulser - et andet kontroversielt emne:

1. HOW CAN I REVIVE A SULFATED BATTERY?:
   formatting link
   Citat: "...As a consequence of parasitic load and natural=20 self-discharge, permanent sulfation occurs as the lead-acid battery=20 discharges while in long term storage...Self discharge is accelerated by =

temperature. Thus, sulfation can be a huge problem for lead-acid=20 batteries not being used, sitting on a dealer's shelf, or in a parked=20 vehicle, especially in HOT temperatures..."

Desulfators and Pulse Chargers:

Lead Acid Battery Desulfation Pulse Generator Some help and information for builders:

Some Technical Details on Lead Acid Batteries The Chemistry of Sulfation, and Why Pulsing Helps:

Citat: "... In the above, the Level One, Two, or Three bonds refer to progressively=20 larger and insoluable crystals of lead sulfate. Like most crystal=20 formation, it is a slow process. So the question is, How could pulse=20 charging affect this situation? According to conventional wisdom, not at =

all. Here is the party line, from a product applications manager at=20 Trojan Battery Co. on pulsing =2E.. Cycling of the battery causes "shedding", or loss of material from the=20 plates. If you see a battery that has reached its limit, you might find=20 chunks of lead on the bottom of the cell, and actual holes in the=20 plates. Nothing's to be done in this case. Excessive charge rate will=20 also cause this to occur. =2E.. Electrolyte stratification occurs when the batteries do not receive=20 sufficient charge rate to cause bubbles to rise and stir the liquid. The =

heavier electrolyte sinks to the bottom of the cell. This renders the=20 lower portion of the plates inactive, and that is where sulfation gets=20 started. Some large batteries use pumps to force the electrolyte to turn =

over. =2E.."

mvh/Glenn

Anders Henriksen wrote: =2E..

Hej Anders

4) Ladnings=F8velser for NiCd akkumulatorer:

Chapter 10: Getting the Most from your Batteries:

Citat: "... The problem with the nickel-based battery is not the cyclic memory but=20 the effects of crystalline formation. =2E.. When NiMH was first introduced there was much publicity about its=20 memory-free status. Today, it is known that this chemistry also suffers=20 from memory but to a lesser extent than the NiCd. =2E.. Tests performed by the US Army have shown that a NiCd cell needs to be=20 discharged to at least 0.6V to effectively break up the more resistant=20 crystalline formation. During recondition, the current must be kept low=20 to prevent cell reversal. [Alts=E5 helst hver celle hver sin afladning] =2E.." "... Figure 10-3: Effects of exercise and recondition. Battery A improved capacity on exercise alone; batteries B and C=20 required recondition. A new battery with excellent readings improved=20 further with recondition. =2E.." "... With charge only (charge-and-use), the annual percentage of battery=20 failure on the USS Eisenhower was 45 percent (see Figure 10-4). When=20 applying exercise, the failure rate was reduced to 15 percent. By far=20 the best results were achieved with recondition. The failure rate=20 dropped to 5 percent. Identical results were attained from the USS=20 George Washington and the USS Ponce. =2E.."

mvh/Glenn

Ja, det er sådan nogle, jeg har arbejdet med og lavet nogle stykker af ;-)

Nåda. Du kan oversætte fra engelsk til dansk :-) Og teknikken anvendes ikke kun til SMPS, men mange steder, hvor høj effektivitet er ønskeligt.

Det har jeg heller ikke skrevet, kun at nogle mener, det giver god mening at PWM-lade blyakkumulatorer, samt at nogle RC-kørere er glade for teknikken. Nogle af disse mener, der er en fordel. Jeg har udelukkende henvist til et par steder, hvor PWM-ladning anbefales/omtales, samt nævnt at visse RC-folk er glade for (om ikke PWM- så puls-) ladning af deres nikkel-baserede batterier, hvad enten de nu anvender den ene eller anden mere eller mindre eksotiske metode. Det nye her er forøvrigt step-ladning.

Men iøvrigt tak for de mange links.

--
Anders Henriksen
supermule [snabela] lite [punktum] dk

Internet? Jeg giver det højest tre år...