Branch's SSG Build

[Branch Gordon]

Music is something I can relate to! So the frequency of the bike wheel is a measurement of how often each magnet passes per second correct? So the magnet right over the core would be the "up" part of the wave, and in between magnets would be the "down" part...is this correct?

So then with tuning you are just matching this wheel frequency with the frequency the coil is producing, so they are in phase with each other?

Is there a way, audio-wise, to listen to the frequency the coil is at?

there are frequencies that are additive in a circuit, its like a LCR circuit or an LC circuit. feed back in an amp can cause it to runaway and blow itself up..... same thing in an SG circuit, it was much more obvious in repulsion mode, where there were 2 or 3 sweet spots in the tuning curve, this was resonance with the coil and the wheels rpm in the bloch wall of the coil core. much less noticable with attraction mode.

Tom C

[Branch Gordon]

What is the oscilloscope measuring when you are looking at an h-wave? Is that the coil frequency?

If so, wouldn't an alternate way of tuning be to just adjust resistance until the wheel frequency matches the coil frequency?

[Branch Gordon]

Here are the baseline curves for my two new batteries after a couple of charge/discharge cycles with a standard charger.

It looks like my charge battery is slightly weaker than my primary battery, so I will probably adjust my discharge amps accordingly to stay within the C20 rate for that battery.

I'm going to run it through one more cycle with the standard charger before beginning some test runs on the SG.

[Branch Gordon]

So I'm doing a few more cycles with a standard charger, and I'm noticing that the amp hours out are decreasing each time. I was thinking that as the plates form, I would get more out...but it doesn't seem to be the case here. They are supposed to be 20AH batteries. First run gave me 13.5, second was around 12, and this one I'm doing now looks like it's going to be even shorter.

I'm thinking maybe this brand of batteries are just...crap? They are lawn and garden batteries, but I know they are designed for CCA applications, not necessarily a long sustained discharge down to 12V.

Thoughts?

[Branch Gordon]

Nevermind...I'm just going to buy some deep cycle batteries. Any recommendations? I'm looking for something around $50. Deep cycle, lead acid (not AGM).

Would these be good? http://www.atbatt.com/product/22980.asp

[Dave Wing]

Branch,

I think those are glass mat batteries you are looking at.

If you have the means go with something like this Trojan Battery Company
Get two 12 volt 1275's and call it a day or get 4 six volt Trojan T-105's. Just my 2 cents.

[Branch Gordon]

Hi Dave-

Wouldn't those be too large for my single coil SG to handle?

I'm trying to keep my battery choice under 20AH

Branch,

I think those are glass mat batteries you are looking at.

If you have the means go with something like this Trojan Battery Company
Get two 12 volt 1275's and call it a day or get 4 six volt Trojan T-105's. Just my 2 cents.

[Tom C]

what is the brand and model of your charger, and what is its charge termination voltage...... you can use the cba to monitor the charging... see where it is leveling off. amazing what you can learn isn't it!!

Tom C

[Branch Gordon]

Haha yes it is. The charger is a Schumacher SEM-1562A 1.5 Amp Speed Charge Maintainer

I have used a DMM to see where it charges up to, and it stops at 15.04V, then drops slightly to 14.99V and hangs there for awhile. Then is goes into a "maintenance" mode, and the voltage drops to 13.6V and hangs there until I disconnect it from the battery.

As I'm reading through some of the reviews here on Amazon.com, it looks like this model has a lot of negative issues...specifically with the "maintenance" mode hurting batteries.

[Branch Gordon]

Would you recommend I get a new charger? Also, when dealing with the lawn/garden batteries I'm thinking I shouldn't discharge them past 12.5V....would you agree with this?

[Tom C]

I dont know anything about that particular brand of charger, I do have a schumacker

Schumacher SC-10030A SpeedCharge 2/12-30/100 Amp Automatic Charger and Maintainer : Amazon.com : Automotive

I am wondering about the batteries, they should get better for a few charges when new as the plates form.... your battery manufacturer will tell you what fully discharged voltage is and you can calculate 80% d.o.d. from there. I would take them back and get some napa lawn tractor batteries.

Tom C

[Branch Gordon]

Yeah I think I will go and get the Napa batteries. Have you had any issues with 80% d.o.d. with those?

What are your thoughts on me converting my current primary battery to an alum battery and using that instead?

I dont know anything about that particular brand of charger, I do have a schumacker

Schumacher SC-10030A SpeedCharge 2/12-30/100 Amp Automatic Charger and Maintainer : Amazon.com : Automotive

I am wondering about the batteries, they should get better for a few charges when new as the plates form.... your battery manufacturer will tell you what fully discharged voltage is and you can calculate 80% d.o.d. from there. I would take them back and get some napa lawn tractor batteries.

Tom C

[Branch Gordon]

I really would like to be sure about these batteries before I purchase them... Which brand does John use?

If I use a 2A12 to charge my primary back up, should that eliminate any issues?

It's weird that my secondary battery was so badly damaged as well, even though it showed signs of charging improvement. I wonder if it's because I was only taking 2AH out of it...so it wasn't experiencing a charge from the SG over it's full range...

[Tom C]

napa lawn tractor battery

[Branch Gordon]

Picked up Napa lawn tractor batteries today. Guy said they just arrived new. Cycling them a few times with standard charger to form the plates. Charting the charge curve with the standard charger to see if there is anything odd going on with my charger that I can see.

I can't find a chart on Napa's website that shows the recommended depth of discharge rates. Right off the shelf it was sitting at 12.65V. 20% of that is 12.13V. Is that a good target not to exceed you think for these batteries?

napa lawn tractor battery