battery charger hack

[Stu Jackson]

Originally Posted by smac999

that still doesn't make any sense. you can't increase voltage across a diode. they drop voltage. the alt webpage is effecting the control wires. yours is direct in the output path. big difference.

if you have 2 diodes in series in the pos line between the charger and battery with correct polarity your charger would be at 14.2 and your battery would be at 13.

reverse polarity it just wouldn't charge and the charger would be at 14.2 and battery at 12.

can you draw a diagram of what you have? maybe I'm missing something.

Having reviewed the UK Smart gauge link earlier provided, I agree. What those diodes did was have the REGULATOR fool the alternator to output higher voltage, and NOT to take a given output and boost it along the output wire.

I'd be as interested in a reply as smac999.

[michaelmrc]

think your missing the point the voltage drop is the trick. the charger senses battery voltage but if the diode is inline with the charger ie battery charger to diode then a jumper to battery positive the charger thinks the battery is lower voltage so increases voltage to try and bring it up. on this charger the voltage sense wire is the charge wire.

[michaelmrc]

heres a quick layout of how its setup.

[michaelmrc]

stu thats exactly whats happening here its just tricking the chargers regulator into thinking it need to have a higher voltage. i had an older toyota 4x4 with a big car audio system in it we did this same hack to the alternator to produce more voltage worked great whole time i had the truck.

[goboatingnow]

Simply putting a diode in series with the output of a battery charger merely causes a voltage drop it can never increase the voltage.

To increase the voltage the charger must have a way if sensing battery voltage at the battery terminals. That's find with a seperate sense line.

You can place the diode in that sense line , cathode towards the charger to fool the sense line sensing and hence raise the charger output.

Perhaps that's what you meant

Dave

[alamoana]

You are correct. The diode is placed inline the voltage sense line, not the chargers output.

[FlyingCloud1937]

Dave,

The diode in series fools the charger, because the charger voltage sensing is tied to the output/charge cable at the charger.

When the he charger isn't charging the diode is blocking, but as soon as the current flows, and the diode is conducting, a reverse voltage at a lower then actual bat voltage is available from the bat.

So now the charger is in flat out mode exceeding its KVA, this will either lead to a burnt out charger or a fire. The diode will not live long either.

Lloyd

Originally Posted by goboatingnow

Simply putting a diode in series with the output of a battery charger merely causes a voltage drop it can never increase the voltage.

To increase the voltage the charger must have a way if sensing battery voltage at the battery terminals. That's find with a seperate sense line.

You can place the diode in that sense line , cathode towards the charger to fool the sense line sensing and hence raise the charger output.

Perhaps that's what you meant

Dave

[alamoana]

What you say is correct, you may be asking the charger to deliver more than it is capable. With the amplepower.com chargers, this is not the case. Plus, if you start with "full" batteries, prior to tricking the charger into delivering a higher voltage, the batteries will only accept a small current, even at tricked high voltages. The diode is placed in the voltage sense line which carries a minute amount of current, so it should not burn down. My diodes worked for several hours and are still good. Regards,

[michaelmrc]

exactly i started with a fully charged battery so when conducting this experiment it was only charging at a max of 2 amps. im using 5404 diodes which are a little more robust and can handle more current.