BU-303: Confusion with Voltages

A battery is an electrochemical device that produces a voltage potential when placing metals of different affinities into an acid solution (electrolyte). The open circuit voltage (OCV) that develops as part of an electrochemical reaction varies with the metals and electrolyte used.

Applying a charge or discharge places the battery into the closed circuit voltage (CCV) condition. Charging raises the voltage and discharging lowers it, simulating a rubber band effect. The voltage behavior under a load and charge is governed by the current flow and the internal battery resistance. A low resistance produces low fluctuation under load or charge; a high resistance causes the voltage to swing excessively. Charging and discharging agitates the battery; full voltage stabilization takes up to 24 hours. Temperature also plays a role; a cold temperature lowers the voltage and heat raises it.

Manufacturers rate a battery by assigning a nominal voltage, and with a few exceptions, these voltages follow an agreed convention. Here are the nominal voltages of the most common batteries in brief.

Lead Acid

The nominal voltage of lead acid is 2 volts per cell, however when measuring the open circuit voltage, the OCV of a charged and rested battery should be 2.1V/cell. Keeping lead acid much below 2.1V/cell will cause the buildup of sulfation. While on float charge, lead acid measures about 2.25V/cell, higher during normal charge.

Nickel-based

In consumer applications, NiCd and NiMH are rated at 1.20V/cell; industrial, aviation and military batteries adhere to the original 1.25V. There is no difference between the 1.20V and 1.25V cell; the marking is simply preference.

Lithium-ion

The nominal voltage of lithium-ion is 3.60V/cell. Some cell manufacturers mark their Li-ion as 3.70V/cell or higher. This offers a marketing advantage because the higher voltage boosts the watt-hours on paper (voltage multiplied by current equals watts). The 3.70V/cell rating also creates unfamiliar references of 11.1V and 14.8V when connecting three and four cells in series rather than the more familiar 10.80V and 14.40V respectively. Equipment manufacturers adhere to the nominal cell voltage of 3.60V for most Li-ion systems as a power source.

How did this higher voltage creep in? The nominal voltage is a function of anode and cathode materials, as well as impedance. Voltage calculations include measuring the mid-way point from a full-charge of 4.20V/cell to the 3.0V/cell cutoff with a 0.5C load. For Li-cobalt the mid-way point is about 3.60V. The same scan done on Li-manganese with a lower internal resistance gives an average voltage of about 3.70V. It should be noted that the higher voltage is often set arbitrarily and does not affect the operation of portable devices or the setting of the chargers. But there are exceptions.

Some Li-ion batteries with LCO architecture feature a surface coating and electrolyte additives that increase the nominal cell voltage and permit higher charge voltages. To get the full capacity, the charge cut-off voltage for these batteries must be set accordingly. Figure 1 shows typical voltage settings.

Nominal cell voltageTypical end-of-dischargeMax charge voltageNotes
3.6V2.8–3.0V4.2VClassic nominal voltage of cobalt-based Li-ion battery
3.7V2.8–3.0V4.2VMarketing advantage. Achieved by low internal resistance
3.8V2.8–3.0V4.35VSurface coating and electrolyte additives. Charger must have correct full-charge voltage for added capacity
3.85V2.8–3.0V4.4VSurface coating and electrolyte additives. Charger must have correct full-charge voltage for added capacity
Figure 1: Voltages of cobalt-based Li-ion batteries.
End-of-charge voltage must be set correctly to achieve the capacity gain.

Battery users want to know if Li-ion cells with higher charge voltages compromise longevity and safety. There is limited information available but what is known is that, yes, these batteries have a shorter cycle life than a regular Li-ion; the calendar life can also be less. Since these batteries are mostly used in consumer products, the longevity can be harmonized with obsolescence, making a shorter battery life acceptable. The benefit is longer a runtime because of the gained Wh (Ah x V). All cells must meet regulatory standards and are safe.

The phosphate-based lithium-ion has a nominal cell voltage of 3.20V and 3.30V; lithium-titanate is 2.40V. This voltage difference makes these chemistries incompatible with regular Li-ion in terms of cell count and charging algorithm.

Last Updated: 25-Oct-2021
Batteries In A Portable World
Batteries In A Portable World

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Bill0267

I found this page when trying to find an answer to the following: I have (the remains of) a fairly new RP-NPF970 DV battery pack. This was returned by a student after they had dropped (?) it smashing the case and breaking some of the internal contacts. Re-making the contacts between the six F-166958 (LS LR18655K FM1588 10117361) cells as apparant would seem to give a pack of 1.2 v (I do not know the charge status before disruction) despite the casing reading 7.4v. Until the casing has been recontructed it is too fragile to put on charge, but because of the high cost of the pack I am reluctant to recycle it at this stage of its life. I am not sure how 6 x 3 volt cells in paralel would give an expected voltage of 7.4v unless there is a hole in my maths. If anyone has any ideas about this or is able to fill the possible hole in my knowledge I would be most gratful.

Sivachander

Marketing low life batteries to induce quicker obsoliscence is criminal. It is touted as a perfectly ethical practice How sad !

James Thomas

How many lithium_ion_cells are in a 3.85V battery and what do STRING or INT has to do with it?

Gold

My question is about Nominal Voltage:
What is the need of having a Nominal voltage when it's half of the peak voltage? Is there a certain use or Servers a certain purpose?

Bob Mack

My question is about Float Voltage:
I have qty-6 12 volt lead acid deep cycle batteries in series for a 30 amp UPS. The UPS keeps them charged and then goes into a float state. All 6 batteries were purchased at the same time and all are the same part number. When charged and sitting at float, one battery voltage measures 14.7 while all the others measure 13.2 to 13.3 volts.
Question: Is this normal and / or OK? And, why would this be the case any why?

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On August 15, 2019, Ray wrote:
At what voltage is a 36V Li-ion battery considered dead? Thanks.
On April 18, 2019, Kiran Thakare wrote:
if we use the 48-volt battery in electric vehicle and use 60/72 volts so what will be the change?
On March 18, 2019, A Fabio wrote:
Ben, you need to look at IATA shipping requirements there is a handy chart you can use to determine the rules on how to package a large quantity of batteries and the weight limits. https://www.lion.com/lion-news/march-2016/iata-updates-lithium-battery-air-shipper-guidance
On January 7, 2019, Ben wrote:
Subscribing to comments.
On January 7, 2019, Ben wrote:
Hello, After some advise, shipping between 50-300 units internationally from the UK. Batteries are 3.7v 1300mAh 4.81Wh lithium ion batteries standard: GB/T 18287-2013 They will be in their device and covered. Who would you recommend for shipping? Both By Air and by Boat? if secured in a Peli case would that be robust enough to contain batteries and be transported? There seems to be so much red tape and struggling to get my head around it. I look forward to any comments! Thanks, Ben
On December 28, 2018, Retro Hipster wrote:
Do you happen to have a part number for the battery Michael? I don't suppose that it is completely out of the question that the voltage would be different, but it seems very odd. Most of the time the Open circuit voltage is determined by the difference in electrical potential of the two electrodes. If it's normal lion technology I would would assume it would have a nominal voltage of 3.7v, but I'm not an expert on this subject.. If it IS a normal lithium-ion technology, then you would probably be able to charge it given you have some information from the datasheet. Charging such a battery would likely need either a charging device designed for it from the manufacturer or you would likely need to get the data sheet on the battery to see it's charge curve. You will end up needing to figure out based on the datasheet at which point you would want to change from doing Constant Current charging to Constant voltage. From there you would likely be able to charge it using a bench power supply. Ramkur and Michael? For more information on how voltages are created and how that voltage is calculated, take a look at this article on Electrode Potential and Galvanic Corrosion. https://www.engineeringtoolbox.com/electrode-potential-d_482.html PS to the maker of this site: thank you for your hard work! This has been a very helpful site to me when I first started learning about Lead Acid Battery testing. It has helped me design some devices for proper testing of our UPS lead-acid batteries. There aren't many good devices for this purpose and I didn't want to have my employees do testing with things like heating elements/light bulbs. ^^;;
On November 25, 2018, Michael wrote:
Hi I am about to purchase a lithium ion battery, its says its nominal voltage is 5V, is this possible? how do I charge it (I would like to use a solar panel and charge controler
On July 18, 2018, Ramkumar wrote:
How does the volt of lithium ion battery is calculated I want to know how to calculate for LiNCA cathode
On July 4, 2018, Alan Smith wrote:
unsubscribed in error- this is for re-subscription to this thread.
On July 2, 2018, Alan Smith wrote:
Have you read anything about the typical behaviours of battery charging? Do you suspect a problem, and why? Also you haven't given any real info (voltages, times, battery history/age/cycles/environment) to allow anyone to give any specific advice- but perhaps you shouldn't be too surprised if you find that you are questioning normal behaviour. On June 29, 2018 at 3:24am Akash thute wrote: After full charging of my Li ion battery pack I took voltage reading. And after I took 3 readings at equal interval of time. I observed that it reduces continuously to specific level. My question is why this was happened ? Is there anything that Li ion battery pack needs time to settle after charger being put off ?
On July 1, 2018, robbo wrote:
On December 18, 2017 at 12:05am Balaji wrote: I have a doubt that Can we increase the capacity of Smart phone battery from 2400mah to 5400mah or 4100mah??? Balaji DO you remember 30MB HDD, remember when Branson said people would be able to sleep on take off?? The most lucrative market @ the moment is energy storage.. .. and if it sounds to good to be true, then it normally is life is a compromise so are batteries, charging, and storage<> , like 40mega pixel cameras are so slow on the web to upload solution touch pad charging<<<<<<<<<<<<<<<>>>>>>>>>>> often life is getting better all the time robbo Ps my old 101 Nokia about 8hrs life ,,had 2 batteries and at least one charger home , office car ,,, <> got me into the charge for life scheme being buying and loyally upgrading ever since
On June 29, 2018, Akash thute wrote:
After full charging of my Li ion battery pack I took voltage reading. And after I took 3 readings at equal interval of time. I observed that it reduces continuously to specific level. My question is why this was happened ? Is there anything that Li ion battery pack needs time to settle after charger being put off ?
On April 12, 2018, Serin Shen wrote:
just wondering what decides the voltage window? the chemistry properties?
On March 15, 2018, Brian Tapley wrote:
Question here. I have what I think is a Li battery pack. It appears to be made from 4 mettal cans (batteries). The open circuit voltage of the pack is 6 volts + or - about a half volt due to measurement limitations of my equipment. I need to replace this pack due to age but cannot find the exact battery. COULD I JUST CONNECT THE GOOD OLD ALKALINE DRY CELLS YOU BUY IN THE HARDWARE STORE (SAME PHYSICAL SIZE AND 4 AT 1.5 VOLT = 6 VOLTS) to this load?? The load is quite low. The reason for the Li battery pack is longevity and cold temperature service but I don't need the cold temp feature and can easily replace normal alkaline on a more frequent basis. I'm looking to have a workable solution at a reasonable cost here.
On March 4, 2018, Harshwardhan Wadikar wrote:
Carbon is a gift from the universe, Coat cathodes with carbon, the capacity fade that happens at the beginning of battery life will reduce substantially.
On February 24, 2018, awx wrote:
the longevity can be harmonized with obsolescence I'm plagiarizing this, next time I have to explain to a customer why their old ass cell phone doesn't hold a charge anymore.
On February 15, 2018, Alan Smith wrote:
'think' That means they are guessing. Don't worry about anything until it is not a guess but is a published specification- you could be wasting a lot of effort. Get these 'people' to quote reliable sources that you can independently check. Can they do that? If it is genuine they will have no problem giving the information without any delay.
On February 12, 2018, NOBADY wrote:
Hi, People I work with think Li-Ion charging voltage will be rising in the future. They expect and want to design around 4.6V charging voltage. Any comments? Thanks!
On December 19, 2017, Alan Smith wrote:
On December 18, 2017 at 12:05am Balaji wrote: I have a doubt that Can we increase the capacity of Smart phone battery from 2400mah to 5400mah or 4100mah??? ----------------------------------------------------------------- You can increase a battery packs capacity to whatever you want BUT it will increase the volume of the battery. The battery chemistry type has a reasonably consistent energy density so to get double the battery capacity you would need a battery of twice the size. Could you get your phones battery cover fitted with a battery that is twice as big? There *is* some difference in energy density of different manufacturers cells so the can be some variations in energy densities (and hence size) but not enough to get those claimed capacities into the same sized pack. In reality you're chasing a small capacity increase, and higher density batteries command a price premium for the larger capacity. Those 'claimed' high capacity batteries are often cheap so there is real serious doubt that they would be using premium cells, and probably construction quality. They should be able to tell you which cells are used in the battery - cell type and model, also capacity (not that I'd necessarily believe what I'm told for cheap battery packs). Get them to open a pack and picture the cell markings. Or the weight of the battery might be a better indicator of the real capacity than what is claimed. This whole scenario is reminiscent of the 18650 lithium cell capacity claims some of which are completely ridiculous- but not quite as widespread and ridiculous. btw avoid any cells with 'fire' as part of the name- Do a websearch to see just what these manufacturers do with 18650 cells- chances are the cells come come from the same factories and the same people are involved. https://lightsngear.com/fake-lithium-battery-capacities/ http://www.torchythebatteryboy.com/p/dangers-of-ultrafire-18650-batteries.html
On December 18, 2017, Balaji wrote:
I have a doubt that Can we increase the capacity of Smart phone battery from 2400mah to 5400mah or 4100mah???
On November 15, 2017, Alan Smith wrote:
from the earlier posts you can see there are various types of phone batteries (eg lion 3.6V or 3.7V so really you need to be more specific. But even with that information you won't get an accurate answer- cells from different cell manufacturers have different specifications (BATTERY CELL manufacturer NOT PHONE manufacturer).
On November 14, 2017, Shamim wrote:
What is the maximum voltage or current generated by a battery of mobile phone? I am talking about surge voltage. Please let me know. Thanks in advance.
On October 26, 2017, robbo wrote:
Ahmed Adel wrote: Hi, I’ve a customer who is insisting on a 127V (Nominal Voltage) battery system &#40;Lead Acid&#41; consisting of 58 cells. We have tried to explain more than once that the Cell nominal voltage is 2V according in order to achieve the required voltage he would need 64 cells rather than 58. Yet the customer is still insisting on his point of view (in French as the customer is from a French speaking country la tension nominal par élément est de 2.2 v). I need some assistance or guidance maybe there is a battery manufacturer who manufactures such cells (2.2V nominal voltage) or maybe there’s some kind of misunderstanding that you can clarify to me. Robbo here Ahmed sounds to me the Frenchman is croaking Tell him a 12V battery is made up of 6x2V cells, we dont call it 13.2V or 14.4Peak do we 125Vdc batteries are not uncommon in Africa just complicated On September 17, 2016 at 10:56pm Zain Tariq wrote: We recently Installed lead Acid Battery Make Happecke Model: 11GroE 1100 2V, 1100Ahr,Cn/1210Ahr C10 Ufloat = 2.23V/cell, total Voltage 125V, Someone else has a 125VDC system his is large @0.137Mw The Chinese make a lot of what they call 120VDC using 20 x 12V or 60 x 2Volt and have chargers and inverters to suit, 240Vdc and 384 are common rail voltages and lately 768Vdc in gaining ground. Their inverters are all transformerless utilizing MPPT over the outdated PWM transformer models Just get him to advise the Battery capacity in A/h and I can design and quote on his system as Project Manager. Using 310Wx 60Cell monos @ 36Vpp ~ 8.15A it would need would need 5 panels per string and wired 5S2P gives ~17A. Hope this shed some light Cheers robbo Also explain that here in Australia we sell wheat by the truckload we dont count individual grains as he does
On October 26, 2017, robbo wrote:
Zain Tariq wrote: We recently Installed lead Acid Battery Make Happecke Model: 11GroE 1100 2V, 1100Ahr,Cn/1210Ahr C10 Ufloat = 2.23V/cell, total Voltage 125V, After one month we loosed the AC supply and we used this battery bank but after 4hours battery voltage reached on 70V and now these all cell voltage not going to up. please advise to us how we can solve this problem. Hey Buddy that a serious battery bank in fact is 1.2Mw and at 650Euro plus each and 60 in a string a major investment. Do you have a warranty with the installer. Batteries of this size are a problem when they go down. Give some more info as to configuration. I guess its in a BIG solar something that pumping out 160/200VDC at around 3 or 400 amps Just do a quick check of input volts and amps, maybe something has vibrated loose at this tension, then check each battery in turn it only takes one dead cell to break the chain PowerSafe 10 OPzS 1000 2V - 1100Ah (10h) Einzelzellen stock a similar battery Ok if yoour German is good Fly me and my test gear over Send me some photos robtaylor.1952@gmail.com Cheers and good luck robbo
On October 23, 2017, Nisarg wrote:
Why a 24V Nicd bat. Shows 31/30V at nearly end of charging cycle ???
On July 5, 2017, Man Man wrote:
What makes you think it actually has bigger capacity, especially if it's from China? What's the biggest capacity presently available in a genuine battery? How many cycles are you counting on it lasting?
On July 5, 2017, oji wrote:
Hello, I want to ask. I have 3.8v 150mAH battery (original) on my pebble smartwatch, is it safe to change the battery to 3.7v with bigger mAH (buy it from China)? Thank you. Oji
On June 29, 2017, Alan wrote:
I've seen batteries with voltages described differently. Ask him to provide a link to the 2V cell specifications he is talking about, that will help you to explain things. Once you have ALL of the information rather than just part of it I think this will be easier to understand and explain. I think it's semantics and different conventions here. Part of the info you need to supply here to get a meaningful response- What configuration of battery would YOU produce normally? (xSyP - x serial and y parallel configuration) Have you asked the potential customer the configuration he was wanting/expecting? Things may then be easier to explain properly- and yes,
On June 28, 2017, Ahmed Adel wrote:
Hi, I've a customer who is insisting on a 127V (Nominal Voltage) battery system &#40;Lead Acid&#41; consisting of 58 cells. We have tried to explain more than once that the Cell nominal voltage is 2V according in order to achieve the required voltage he would need 64 cells rather than 58. Yet the customer is still insisting on his point of view (in French as the customer is from a French speaking country la tension nominal par élément est de 2.2 v). I need some assistance or guidance maybe there is a battery manufacturer who manufactures such cells (2.2V nominal voltage) or maybe there's some kind of misunderstanding that you can clarify to me. Thanks Ahmed
On May 15, 2017, Harsh Jain wrote:
Excellent information
On January 31, 2017, Alan Smith wrote:
without doing a proper discharge graph - the only real way to work it out - how about V = F - [( F - L) * D] V = approximate Voltage Fully Charged Voltage - F Voltage of Discharged cell - L Degradation - D ( so 80% is 0.8 )
On January 31, 2017, Gowda wrote:
what will be the cell voltage if battery reaches its 80% degradation
On November 25, 2016, Gabo wrote:
But nowadays we have Li Ion batteries in our mobiles with voltage over 5 volts ... how is this possible?
On September 18, 2016, Zain Tariq wrote:
We recently Installed lead Acid Battery Make Happecke Model: 11GroE 1100 2V, 1100Ahr,Cn/1210Ahr C10 Ufloat = 2.23V/cell, total Voltage 125V, After one month we loosed the AC supply and we used this battery bank but after 4hours battery voltage reached on 70V and now these all cell voltage not going to up. please advise to us how we can solve this problem.
On August 11, 2016, Anish bhurke wrote:
What is the expected open circuit voltage of a 12V lead acid battery
On July 23, 2016, framistat wrote:
Looking at a Sanyo Eneloop bicycle circa 2010, battery packs no longer available even from Japan (Amazon or Rakuten). The bike has a 250W brushless motor. The battery pack is stated as 25.2V 5.7Ah. Most 250W motors today are 24V. So I'm wondering why they would have used a nonstandard lithium ion 25.2V battery pack... must be 7 cells?
On July 1, 2016, gat wrote:
why complicate using 9v battery
On May 5, 2016, Alan Smith wrote:
LiFePO4? A table showing the chemistry and the voltage would give far greater clarity than this style of writing, the information *is* good but not easy to pick out the most relevant facts.
On January 29, 2016, NightShadow wrote:
So I have something that needs 150 volts to be powered. stun guns on average carry a punch of about 1.5 million volts. how is it that I can't find a battery that gives me an output of 150 volts? what battery should I use and how long will it last if it would be running for 8-10 hours a day?
On November 5, 2015, JEC wrote:
Typical battery charger puts in Amps not volts correct? As dc amps goes in, doesn't battery voltage increase?
On October 2, 2015, enver salimov wrote:
i thing this is so beatufull
On September 25, 2015, HardwareFreak wrote:
Hi, How to calculate the time taken for a Li-ion battery to discharge from 4.2V to 3.4V, @ 2A load current...? Can anyone pl help.
On September 1, 2015, Bishwo wrote:
Hello, I have a 6V battery to run my system which also works in 6 volt that draws 0.5 AH. I made a parallel combination with two 12AH to make 24 AH so that I don't need to recharge the battery for 48 hours. Once accidentally connected negative to positive and positive to negative which damaged the system and I had to repair it. DO you think that accident has any impact on the battery? Can I use the same battery again to run the system?
On April 22, 2015, Tom wrote:
I am currently charging a battery (inside a device, and I have no details about it, I just know it is rechargeable). Using my universal power supply, I have the voltage up and the current reduced to 200mA. Currently the voltage is at 8.87V. any ideas what voltage will indicate a full charge?
On March 24, 2015, krishna wrote:
How much highest ratting of dc batteries
On March 23, 2015, JM wrote:
If you still have the curiosity itch, try measuring the battery voltage under load (while it's being used by a device). This should give you an accurate reading as to how much voltage your battery is really pushing. Do this at your own risk and be careful. Plan how you're going to go about measuring it (don't allow the positive and negative to touch each other and you'll be fine). Probably not worth the risk, but the idea is there if you want to try it.
On March 18, 2015, James Traxel wrote:
My instrument rechargeable battery got weak and I went to replace it. It is an "A" size battery. When I measured the voltage it was 1.8 v. How can this be? The battery that I purchased was NiMH of 1.2 v so I'm left scratching my head.
On February 18, 2015, tony wrote:
i am not satishfy with the seriese combination of cells.
On February 17, 2015, Tevita Kirailevu wrote:
When reading an analogue meter , which place in it should i read the battery voltage (can you send a image of it on where to locate it.
On February 8, 2015, Iain wrote:
I removed a 3 volt CR2 lithium battery from my security system because I had a low battery reading. I am puzzled because after removing it, I found that the battery still read 3 volts. Can you explain this?
On January 6, 2015, SURESHKUMAR wrote:
My car is alto k10 maruthi, pls inform me using horn details,battery volts and horn volts. regards suresh
On December 3, 2014, SHAILENDRA jain wrote:
can we connect in a battery bank of 12 v 150ah battery with 12 v 100ah battery .
On December 2, 2014, Zeinab wrote:
hello people , actually i am inquiring about OCV most problem and how it affects the battery
On October 6, 2014, sandeep wrote:
Sir is there any problem in charging a 1.2 volt battery by a 9 volt dc. 2000 mA output charger
On April 20, 2014, ruby wrote:
I wonder how many more projects are out there secretly
On February 27, 2014, harry potter wrote:
do you use skype? If yes we can also discuss there. - It would be awsome if a discussion of e.g. batteries could be done between different scientist via skype or something else, so that everyone get soon help… i just want to ask something about that battery and explain me how to make it in russia\\ benelmokadem <a href="http://harrypottermoviesinorder.net">harry potter movies in order</a>
On January 20, 2014, jeeva wrote:
Sent me email for battery information
On November 26, 2013, Ajay Pundir wrote:
just love your site. it has increased my knowledge of batteries and charging technology. thanks
On August 26, 2013, omar wrote:
Can i charge my li-ion battery with a 9v ac adapter?
On January 22, 2013, shaibu wrote:
how to calculate the total heat loss of VRLA batteries.
On September 19, 2012, mark wik wrote:
love your site. hopefully i will learn many things and impress my friennds and associates with my knowledge of battery and charging technology. thanks, mrw
On December 4, 2011, Man Man wrote:
And "(OCV)attained".
On December 4, 2011, Man Man wrote:
Italso - sounds like an Italian battery company. Needs a space, as does "series.Let".
On August 25, 2011, Ian wrote:
What voltage is required to charge a 12 volt gel battery . IAN
On May 25, 2011, Robert Atkinson, Jr. wrote:
The author made a slight error in the formula for energy. Volts (V) times Amps (A) equals Power in Watts (W), not energy (Wh). Since power is energy per unit of time, then Power (W) x time (hours) equals energy (Wh). To convert Watt-hours to Joules (the MKS measurement system's preferred unit) Multiply Watt-hours by 3600 sec/hour to get Joules (1W= 1Joule/sec, and 3600 sec=1 hour, or 60 sec/minute x 60 minutes/hour= 3600 sec/hour).
On May 14, 2011, dean mancis wrote:
hi just wondering what is the current flow in a singel 12v headlamp circuit with 100w globe is it 10A? And how much current will flow through a cicuit that has a 12volt power supply and a resistance of 6 ohms is it 2 Amps . What is required to drive 1.5A of current through a 30 ohm load is it 45v?
On March 18, 2011, MAHESH wrote:
want details of batteries
On March 7, 2011, Edward Baxter wrote:
I am in Mexico. Can I use a 3.6v lithium as a replacement for a 3v lithium in my dive computer.
On March 4, 2011, BWMichael wrote:
its funny how people think a lithium battery with 3.7v written on the packaging is better than one that says 3.6v