| "pfjw@aol.com" <peterwieck33@gmail.com>: Jul 07 09:10AM -0700 You need a basic lesson in Lead Acid Battery chemistry: Terms: Amps - the amount of current a battery can put out at a given voltage. Volt - the energy behind those Amps above. Amp-Hour - How much energy that battery can produce for one hour at a given voltage. Self-Discharge - the amount of potential energy the battery loses while sitting inert. Now, a battery is a chemical engine, in this case using lead and lead dioxide plates submerged in diluted sulphuric acid, separated into cells. The chemical reaction (exactly what that is not important) is limited by the surface area available for the reaction and the strength of the electrolyte (acid). So, a 450AH battery is one that will deliver 450 amps for one hour before complete discharge. Such a battery will self-discharge at 22.5 AH per month. For ease-of-math, let's use one (1) AH per day. That is 42 ma per hour. So a maintenance charger would have to make at least 42 ma per hour to overcome self-discharge. Anything more than that will (theoretically) 'charge' the battery, assuming a (partially) discharged state initially. A fully charged battery subject to additional charging (overcharge) will 'sulphate' - break down the water in the electrolyte into Oxygen and Hydrogen, increasing the acid concentration. Actual voltages are greater than 2.1 V per cell in order to initiate and maintain the chemical reaction required to reverse discharge. Meaning that charging a battery is a balancing act. Going through your questions: a) Absolute minimum charging current: That which will overcome self-discharge. b & c) Some industrial batteries have the individual cell anodes and cathodes accessible for just that purpose. Otherwise, one takes the total divided by six (6) for a nominal 12V battery. The resting voltage for a lead-acid battery is very roughly 2.1 V per cell. Temperature Charging Voltage/Cell Charging Voltage (12V) Gassing Voltages 20 °C 2.43 to 2.53 14.58 to 15.18 2.415 14.49 Temperature: Chemistry, remember. Reactions are affected by temperature. Charging Voltage per Cell: What it takes to initiate and maintain the chemical reaction for charging. NOT equivalent to resting voltage. Gassing Voltage: what will initiate electrolysis in a fully discharged battery, and cause some electrolysis during the charging process. WHAT THIS MEANS: why it is that lead-acid batteries need to be checked for electrolyte status water is lost during the charging process, always, to some degree. Lead acid batteries are not complicated, but they are also prone to abuse and failure if the basic chemistry is not understood. Peter Wieck Melrose Park, PA |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Jul 07 04:29AM -0700 After such a complete and detailed request, you are sure to get any number of equally complete and detailed responses. Peter Wieck Melrose Park, PA |
| Phil Allison <pallison49@gmail.com>: Jul 06 04:47PM -0700 katlego...@gmail.com wrote: =============================== > I got pioneer sx-700t and I just want to fix it ** ROTFL !! https://www.youtube.com/watch?reload=9&v=pBN9fR8ORyo .... Phil |
| Pimpom <nobody@nowhere.com>: Jul 07 11:59AM +0530 On 7/7/2020 5:17 AM, Phil Allison wrote: > ** ROTFL !! > https://www.youtube.com/watch?reload=9&v=pBN9fR8ORyo > .... Phil I use a paintbrush and a blower. |
| Phil Allison <pallison49@gmail.com>: Jul 07 01:35AM -0700 Pimpom wrote: ============ > I use a paintbrush and a blower. ** Waaayyy too messy to do indoors. So I use a vacuum cleaner and 1 inch paintbrush in a similar way. Massively clogged amps with internal fans get done out on my balcony. Diabolical cases ( ie filthy fans) get a bath in the sink with hot water and detergent. Then dried in the oven at low temp - I kid you not. ..... Phil |
| Trevor Wilson <trevor@rageaudio.com.au>: Jul 07 07:30PM +1000 > I got pioneer sx-700t and I just want to fix it **I wanna fix my car, but I don't know anything about engines and gearboxes. Maybe I can ask some random people on the internet? -- Trevor Wilson www.rageaudio.com.au -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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