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??? Wet cell Truck Batterys
- Thread starter snow bird
- Start date
I just did a quick search and found this.
The rule of thumb for converting CCA to Ah is dividing it by a 7.25 constant. For instance, if your battery is marked with a 1450 CCA, it represents 200 Ah. A battery of this rating should last for 25 hours while producing power of 8 amps
The rule of thumb for converting CCA to Ah is dividing it by a 7.25 constant. For instance, if your battery is marked with a 1450 CCA, it represents 200 Ah. A battery of this rating should last for 25 hours while producing power of 8 amps
In old school days...That's meaning really way back when...
We used to calculate by two known values, the LENGTH of time in hours - and the CCA (Cold Cranking Amps)...
So if you had a 770 CCA battery and you wanted to know the Amp/Hrs Ah you have to use - then you divide the Length of Time (Hours) into the Battery's CCA rating...
Let's say 36 Hours (1 an 1/2 Days as if we were Camping)
X = 770 / 36
OR
X = 21 Amp/Hours (Rounded Up)
Is that correct? No, it is not because you're assuming a Rated voltage sustained for that length of time...
So to remember the application of above, you really should take 80% of the CCA and Also remember to degrade the rating even lower to compensate for temperature... you can derate up to 40% of the CCA rating
We used to calculate by two known values, the LENGTH of time in hours - and the CCA (Cold Cranking Amps)...
So if you had a 770 CCA battery and you wanted to know the Amp/Hrs Ah you have to use - then you divide the Length of Time (Hours) into the Battery's CCA rating...
Let's say 36 Hours (1 an 1/2 Days as if we were Camping)
X = 770 / 36
OR
X = 21 Amp/Hours (Rounded Up)
Is that correct? No, it is not because you're assuming a Rated voltage sustained for that length of time...
So to remember the application of above, you really should take 80% of the CCA and Also remember to degrade the rating even lower to compensate for temperature... you can derate up to 40% of the CCA rating
Don’t even start on, “probability distribution curves”, or, “observer-influenced outcomes”.
He just needs to make a measurement to collapse the wave function.
The dimension in which he’s existent is good enough already.
(Okay, so not really the best example of disquisition to have fun with. But to wish all blessed Easter, HA, where the possible isn’t bound by the Lilliputians).
.
In a separate observation:
Any Wet-Cell battery or ANY type of storage device for electrical Charge has an internal resistance...
That is a resistive effect to the charge flow whether being recharged, or discharged...
So to think of a battery as "Amps per Hour" means you have to compensate for a given set of rules.
How much current do you need...
The Resistive element of the item to be powered by the Battery (The R of the E/I=R) How much power it needs in Power Consumption - per a Voltage it needs in order to operate.
Because ...
When a battery is fully charged, it appears to the charger as an infinite resistive device - it cannot take in more current, just the occurrence of electrolysis of the wet-cell medium - it looks like a very big resistor...
But, that same battery can appear as a Constant Current device to a device taking delivery of that charge until it loses its' ability to overcome it's own internal resistance to push that current into the device no matter what the voltage output it has available..
But when you recharge that battery, it again starts to look like a VERY LOW resistance that will rise in ohmic or impedance values until it can no longer accept a charge to it's plates, but only as a resistor to the power being applied across it's terminals - again a very large resistor load.
So when you look at Amps per Hour, you need to consider the devices own power needs and what you use to send power to the device, be it a LINEAR regulator, or a Switching Power Supply or a dynamic resistive element like a lamp or bulb filament onto a simple dropping resistor. all (of them) drop power across their leads as a load to the battery and how the load appears in resistance or impedance affects that length of life between recharges
Any Wet-Cell battery or ANY type of storage device for electrical Charge has an internal resistance...
That is a resistive effect to the charge flow whether being recharged, or discharged...
So to think of a battery as "Amps per Hour" means you have to compensate for a given set of rules.
How much current do you need...
The Resistive element of the item to be powered by the Battery (The R of the E/I=R) How much power it needs in Power Consumption - per a Voltage it needs in order to operate.
Because ...
When a battery is fully charged, it appears to the charger as an infinite resistive device - it cannot take in more current, just the occurrence of electrolysis of the wet-cell medium - it looks like a very big resistor...
But, that same battery can appear as a Constant Current device to a device taking delivery of that charge until it loses its' ability to overcome it's own internal resistance to push that current into the device no matter what the voltage output it has available..
But when you recharge that battery, it again starts to look like a VERY LOW resistance that will rise in ohmic or impedance values until it can no longer accept a charge to it's plates, but only as a resistor to the power being applied across it's terminals - again a very large resistor load.
So when you look at Amps per Hour, you need to consider the devices own power needs and what you use to send power to the device, be it a LINEAR regulator, or a Switching Power Supply or a dynamic resistive element like a lamp or bulb filament onto a simple dropping resistor. all (of them) drop power across their leads as a load to the battery and how the load appears in resistance or impedance affects that length of life between recharges
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Ok I thank I need to Go hide my Easter Eggs For each Egg I find I get to eat One >WINK< Happy Easter All Hope We all get Throw this soon .
Okay...was not going to go there but remember some batteries will seem to be rated wonderfully high in CCA simply due to the surface area of the plates, but not the capacity of the electrolyte in volume and Specific Gravity.
So those reading this have been warned - you'll get a lot of current, but very little time to use that current.
I'm trying to locate the original conditions of the testing they used to do such method of measurement - the starter - cables solenoid and engine torque needs to turn it over which affect the Amperage draw.
But that is a story for others to possibly tell...
You on the other hand, Please heed the need to take your own advice...
You be safe as well, else we will miss your debacle-debates and sage advisories from the road...
The way I figure my battery Ah is to use it until it runs down. Then I see how long it took to do that.
Then I tell myself to remember to turn off the dome light before I get out of the car.
Then I tell myself to remember to turn off the dome light before I get out of the car.
Shadetree Mechanic
Delaware Base Station 808
I hope you are not using these in the house..... the charging and discharging process gives off a hydrogen gas along with oxygen. My exgirlfriends little brother used a car battery and a battery charger to power a car stereo in his bedroom. One day he took the gator clamp off of one of the battery terminals and jumped a spark......
It blew the top clean off of it. He got battery acid in his eyes and I had to help him to the bathroom to wash it out.
It blew the top clean off of it. He got battery acid in his eyes and I had to help him to the bathroom to wash it out.
No They Will be in the Camper Storage box Vented with a fan on when charging.