Runnning AGMs 1A didoe to boost voltage ~.4V-1V to top up your AGM battery (1 Viewer)

[veiloctane]

found this video



I have done mine a little different because I wanted to keep my fuse in place also cheap less than $5

so what i have done different is add a 1A diode to the Alternator sense wire silver stripe always facing the alternator this 1A diode will boost voltage from .4V-1V to top up your AGM battery

here is a video explaining how it works

 

[-MaTTi-]

I’ve used this almost 10 year now: 7.5A MK2 Micro Blade/Low Profile (Electronic fuse version) | HKB Electronics - https://www.hkbelect.com/product/143-mk3-micro-blade-75a-electronic-fuse-version-2013/

 

[jellis]

Can someone please explain to me why putting a diode in the Charge fuse should affect the charging voltage at all? This goes to the L wire on our alternators. The L wire/terminal is a ground path for the charge lamp in the dash cluster, and on diesels also involves some other systems such as the pre-heat timer. Basically my understanding is that the L terminal is an OUTPUT of the alternator not an INPUT. This also makes it a very bad idea to ditch the fuse; the fuse is there by design because it's a live circuit that needs a fuse.

Pun intended: It makes way more sense to screw with the Sense wire/terminal on our vehicles. The S terminal is what the voltage regulator should be using to adjust the output voltage of the alternator.

I'm not sure how that diode in the Charge fuse is working to adjust alternator output, but the whole system (Charge fuse circuit + voltage regulator) definitely isn't intended to be screwed with in this way.

 

[TheBussman]

Can someone please explain to me why putting a diode in the Charge fuse should affect the charging voltage at all? This goes to the L wire on our alternators. The L wire/terminal is a ground path for the charge lamp in the dash cluster, and on diesels also involves some other systems such as the pre-heat timer. Basically my understanding is that the L terminal is an OUTPUT of the alternator not an INPUT. This also makes it a very bad idea to ditch the fuse; the fuse is there by design because it's a live circuit that needs a fuse.

Pun intended: It makes way more sense to screw with the Sense wire/terminal on our vehicles. The S terminal is what the voltage regulator should be using to adjust the output voltage of the alternator.

I'm not sure how that diode in the Charge fuse is working to adjust alternator output, but the whole system (Charge fuse circuit + voltage regulator) definitely isn't intended to be screwed with in this way.

your right the diode should be used on the sense wire (there is a sense wire fuse on some trucks), good point do not use the diode in place of the fuse, i always install the diode under the fuse box in its own fuse holder. The reason why it works is that a diode creates a voltage drop, so the alternator thinks that the battery voltage is about 0.4 volts lower than it really is. I've done this mod in a on plenty of customer's trucks and works well.

 

[jellis]

Thanks for the confirmation. Is it easy to tap into the S wire at that fuse box? That would be an elegant solution!

I understand how the diode works to create a voltage drop as a component, and why this works to boost ouput--on the S line. But I don't understand why it actually boosts alternator output when placed on the L wire since that line, ostensibly, isn't used to control output by the voltage regulator?!? Also you'd think that the charge light would never go on as the diode should be breaking the ground path when placed in its normal orientation of having the anode on the L wire side of the circuit at the fuse.

 

[TheBussman]

Thanks for the confirmation. Is it easy to tap into the S wire at that fuse box? That would be an elegant solution!

I understand how the diode works to create a voltage drop as a component, and why this works to boost ouput--on the S line. But I don't understand why it actually boosts alternator output when placed on the L wire since that line, ostensibly, isn't used to control output by the voltage regulator?!? Also you'd think that the charge light would never go on as the diode should be breaking the ground path when placed in its normal orientation of having the anode on the L wire side of the circuit at the fuse.

I've never tried it on the L line doesn't sound like a good idea to me. I've never installed one on a 80 yet, the newer Toyota trucks are all pretty easy to install under the fuse box with an inline fuse holder, it can be easily removed with no tools in the event you want to go back to standard battery. I just bought an AGM battery for my 80 so I'm sure I'll look into this soon, need to get it running first though.