| jacquesl |
How to charge a normal lead acid car battery and an Absorbent glass mat 7ah battery
I have a diode built into my power supply
How can I build a charger that will maintain the battery for then needed, it’s like a UPS type
Will it work if I use my 1.5A variable power supply and set the output to exactly 13.80 volt DC, will that charge my battery to 13.80 and maintain it without overcharging for a couple of years and without making gas builds ups
In my test it’s a discharged battery and the power supply is set to 13,80V DC and if I connect the wires the voltage drop down to 13.40v and it charge at a rate of 0.20A, but why not 1A or 1,5A ? |
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| leto |
| quote: | Originally posted by jacquesl
it charge at a rate of 0.20A, but why not 1A or 1,5A ? |
Mainly because of battery overheating risks... I think !:rolleyes: :confused: |
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| Anthony C Smith |
the best way to charge a SLA or Vrsla type battery is using a controlled impedance charger.
sounds bad but in practice its a 317 regulator from nat semi or sgs. sgs has an app in the l317 data sheet on this, circuit is simple placing a .22 R resistor in serise with the output, with feed back poost resistor, output impedance is them RS (0.22)*Rf/Ri so real resistor is .22 R, apparent is much higher. see http://www.st.com/stonline/products.../2154/lm317.pdf
figure 12
works for all batteries of the sla type I have tried, prevents boiling the battery. |
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| jacquesl |
| Thanks man, it looks nice, I’ll try it out, I have some LM317 regulators, and in my datasheet from “Fairchild semiconductors” they don’t give some sweet examples from the LM317. |
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