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Thread: 8 Volt Battery

  1. #1
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    8 Volt Battery

    Can I charge an 8 volt battery with a 6/12 volt charger. It's to go in a 1942 Jeep and has 520 cca

  2. #2
    Bloke with the stick Gix11's Avatar
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    Check this Terry: http://community.cartalk.com/discuss...8-volt-battery

    Seems that 6volt setting won't charge it and 12 volt will be too much, so they are loading the 12 volt so it is reduced by the time it reaches the battery. Very hit and miss though. They alos suggest how to make your own, which seems like somewhat of a time bomb! Check it anyway.

    Also this: http://www.diyelectriccar.com/forums...12v-33900.html

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    Thanks Si

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    ASF Standard Full Member Redmohawk's Avatar
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    A 4 cell lead acid (8 volt battery) has a charged voltage point of 9.2 volts a 12v battery has an end poing charge of 13.8 so you need to drop 4.6 volts easyest way to drop the voltage without dropping the charge current to much is diodes (used in a bike Reg to turn the AC into DC for your battery) they have a voltage drop of 0.7v per diode . I have a shit load of em for car alts (auto elec) .

    How many amps is your 12v charger ? I'll solder up a pack of diodes for you and heat shrink em. All you'll have to do is use a jumper lead and clamp the diode pack in between the positive off the charger then use the jumper lead to go from the diode pack to the battery.

    Pm me your address and I'll make it and post it tomorrow.

  5. #5
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    Quote Originally Posted by Redmohawk View Post
    A 4 cell lead acid (8 volt battery) has a charged voltage point of 9.2 volts a 12v battery has an end poing charge of 13.8 so you need to drop 4.6 volts easyest way to drop the voltage without dropping the charge current to much is diodes (used in a bike Reg to turn the AC into DC for your battery) they have a voltage drop of 0.7v per diode . I have a shit load of em for car alts (auto elec) .

    How many amps is your 12v charger ? I'll solder up a pack of diodes for you and heat shrink em. All you'll have to do is use a jumper lead and clamp the diode pack in between the positive off the charger then use the jumper lead to go from the diode pack to the battery.

    Pm me your address and I'll make it and post it tomorrow.
    See ya' just new Red would come along and sort it for you!


  6. #6
    ASF Standard Full Member Redmohawk's Avatar
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    On it way bloke

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    Cheers Bro

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    Tyre destroying, mad bastard menace
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    What about using a 9V plug pack / transformer thingy? I've got one here that was off an old landline display phone - 9V DC output, 350mA.

    I know it would take a while to charge, but it would probably work OK, yes??

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    Arrived today, battery's sucking in a bit under an amp

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    ASF Standard Full Member Redmohawk's Avatar
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    That will do nice, being 8 volt with the diodes it will take a little longer to charge but 1 amp wont cook/boil your battery .

  11. #11
    Tyre destroying, mad bastard menace
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    Hey Adam, is there anyway to adapt a 12v ctek trickle charger to drop down and charge a 6v Postie Battery? Will your diode method work for this as well?

  12. #12
    ASF Standard Full Member Redmohawk's Avatar
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    yep work just fine with a dumb trickel charger if its got a sencing circuit (smart charger it might confuse it though)

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