Charging 3 105 AH batteries with SSG

[Gary Hammond]

Hi,
.........I'm hoping to get all of them equalized and topping out at 13.8 volts in 15 minutes. This may take awhile. But it appears, just starting out, that the load is running mostly off the radiant and maybe stealing the surface charge. ..................

Well that isn't happening. After running for several hours each battery was either taking longer to charge to the same voltage or if always charged the same length of time would charge back to a lower voltage. So all the batteries were very slowly loosing charge.

The batteries must be absorbing all the spike as it doesn't show much at all when scoping the radiant collection winding.

I scoped again directly across the radiant collection winding with the 30 watt headlamp in the circuit and it showed about a 15 volt spike. About 1/3 the value of what was appearing across the transistors. I think I need a stronger SSG with more collection windings for this to work properly with these size batteries.

[John_Koorn]

Hi Gary,

Yes. I was going to suggest that the batteries are too big for that SSG. You need to be able to take them up to ~15.8V otherwise you'll slowly kill them.

John K.

[Gary Hammond]

Hi,

Shortly after my last post in this thread, I rewired the five strand coil to run on three strands and collect the radiant on two strands. This didn't really make much difference in the way it performed, as it still ran about the same speed and charged at the same rate. The batteries were still losing charge over time. So I stopped working on it until this past week.

I decided to try splitting the negative and using my better SSG with seven strands running in conventional radiant mode. This is the SSG I showed in my first post of this thread. I discovered that by rearranging the battery locations in the 3 battery supply (using a common positive and taking power between the negatives) I could apply the radiant directly to the battery being charged from the regular SSG output. The charging looked pretty good, so I had my grandson help me rewire the circuit breakers last Thursday so I could easily rotate the batteries.

I've just started testing this new set up and don't have any meaningful results yet. It does, however, bring the charge battery up a little faster and a little higher than the other SSG and "split the positive" did. Will post some photos and data results after I've ran it some more. This one is double pulsing and running at 206 RPM. I want to get the speed up and into single pulsing if I can by readjusting all the parameters.

[John_Koorn]

Hi Gary,

A good rule of thumb I use is about 1 watt of input power for 1 amp hour of battery you're charging. When I set my SS SG to this I get about a C20 rate of charge. So for a 100AH battery you'll need an SG that takes about 100W to run.

John K.

[Aaron Murakami]

Hi Gary,

A good rule of thumb I use is about 1 watt of input power for 1 amp hour of battery you're charging. When I set my SS SG to this I get about a C20 rate of charge. So for a 100AH battery you'll need an SG that takes about 100W to run.

John K.

I find that a typical coil with 7-8 power windings will draw a ballpark of about 20 watts - so it would take a 5 coiler ideally for the 100 ah battery bank. Would you say that matches what you've seen?

A single coil with 7 power windings for example can barely push a 35 amp hour battery into the 14 volt range.

[Gary Hammond]

Hi John and Aaron,

Thanks for the feedback. What you are saying sounds about right. In the normal single battery supply my 7 strand SSG will charge a 13AH lawn battery to well over 16 volts. It does it very quickly in generator mode and a little slower in radiant mode. And it will push a 30AH car battery well over 15 volts in generator mode. It's definitely too small for the 100AH batteries I'm playing with now. I may add more coils to it at a later date. In the meantime, I'm just topping them off with my 10A12 charger to keep them in reasonably good condition.

What I'm experimenting with is comparing normal charging to the "three battery supply" rotation in a "split the negative" arrangement with radiant spikes added to the battery under charge. It takes about an hour to pull them back up to 14 volts using this method, which I thought was pretty good for this size of batteries. It won't top them off, so after I've cycled them all a couple of times I finish charging each one individually to 15 volts on the 10A12.

I think raising each battery to 24 volts would also make a big improvement, as well as switching to faster diodes to collect the radiant. Or I could invest in some 30 AH batteries and leave it the way it is for now. But first, I need to finish up a couple of other projects that are higher on my priority list.

[John_Koorn]

I find that a typical coil with 7-8 power windings will draw a ballpark of about 20 watts - so it would take a 5 coiler ideally for the 100 ah battery bank. Would you say that matches what you've seen?

A single coil with 7 power windings for example can barely push a 35 amp hour battery into the 14 volt range.

Yes Aaron, 20W is in the ball park for a 7-8 strand coil. So I'd expect it to charge a 20Ah battery well, probably no bigger than a 25Ah. As I said, it's a guide. There's a lot of variables - Mode 1, generator mode, 3 battery switch, rotored SG, SS SG, etc.

You really need to push the battery to the top of the charge curve for effective de-sulfation.

John K.

[Aaron Murakami]

Yes Aaron, 20W is in the ball park for a 7-8 strand coil. So I'd expect it to charge a 20Ah battery well, probably no bigger than a 25Ah. As I said, it's a guide. There's a lot of variables - Mode 1, generator mode, 3 battery switch, rotored SG, SS SG, etc.

You really need to push the battery to the top of the charge curve for effective de-sulfation.

John K.

Yes, you did mention 15.8 volts - that sounds a bit hot to me but maybe not.

However, something like the CBA IV - Pro or non-Pro by West Mountain Radio: http://www.westmountainradio.com/pro...oducts_id=cba4

Everyone experimenting with charging/discharging batteries should have one.

When you see the charge graph ramp up then you see the dip showing the impedance dropped from the final layers of sulfation dissolving into solution, then you know you have reversed the chemistry on the battery. I think most lead acid batteries are in the low 15's and amg/gel is around 14.8 or so. 15.8 again sounds a little hot to me, but if anyone looks at the charts, the dip in the voltage at the end will tell you where that optimum topping voltage is for THAT particular battery and they will definitely vary a bit.

That Computerized Battery Analyzer is not just good for monitoring charging curves, it has a constant current discharge mode so you can monitor what you actually got out of the battery.

[Faraday88]

Yes, you did mention 15.8 volts - that sounds a bit hot to me but maybe not.

However, something like the CBA IV - Pro or non-Pro by West Mountain Radio: http://www.westmountainradio.com/pro...oducts_id=cba4

Everyone experimenting with charging/discharging batteries should have one.

When you see the charge graph ramp up then you see the dip showing the impedance dropped from the final layers of sulfation dissolving into solution, then you know you have reversed the chemistry on the battery. I think most lead acid batteries are in the low 15's and amg/gel is around 14.8 or so. 15.8 again sounds a little hot to me, but if anyone looks at the charts, the dip in the voltage at the end will tell you where that optimum topping voltage is for THAT particular battery and they will definitely vary a bit.

That Computerized Battery Analyzer is not just good for monitoring charging curves, it has a constant current discharge mode so you can monitor what you actually got out of the battery.

Hi Aaron,
Yes i guess we should first estimate what a battery gives out first(base quality) of the given Battery and the time it takes to charge it up to that 'Cold-boiling' regime(15.8V for true deep cycle, 14.5 for agm/SLA ect) and this you do by first Discharging a Standard mode charged battery and then from the next cycle on wards use the SG to start the cycle test. no given battery is even 80% of its factory rated Capacity in my guess. The battery servos to the given load over cycles and indeed shows improvement in COP as well! The CBAIV is a very important tool undoubtedly! However im a bit skeptical of using it for Charging monitoring purpose as you can have an accidental opening of the SG out put that can definitely kill the CBAIV.
Rgds,
Faraday88.

[Aaron Murakami]

Hi Aaron,
Yes i guess we should first estimate what a battery gives out first(base quality) of the given Battery and the time it takes to charge it up to that 'Cold-boiling' regime(15.8V for true deep cycle, 14.5 for agm/SLA ect) and this you do by first Discharging a Standard mode charged battery and then from the next cycle on wards use the SG to start the cycle test. no given battery is even 80% of its factory rated Capacity in my guess. The battery servos to the given load over cycles and indeed shows improvement in COP as well! The CBAIV is a very important tool undoubtedly! However im a bit skeptical of using it for Charging monitoring purpose as you can have an accidental opening of the SG out put that can definitely kill the CBAIV.
Rgds,
Faraday88.

I think the 15.8v comes from the Battery Bible. The chart that shows the topping voltage dip is based on a hair over 2.6 volts per cell. At Bedini's around 2004 or so when Peter worked there for a year, they did a lot of non-stop charging/discharging tests and found that the low 15's is where that topping voltage dip happens on the charging graph - I don't think they ever needed to go above 15.3 volts.

What I found with new deep cycles is that I get very close to 100% of the manufacturer's rating based on a 20 hour discharge. When I put a 2A12 on the battery then discharge after a full charge when it is new, I have gotten 110% of the manufacturer's rating. That was with 1 single charge cycle after discharging it.

How will an "opening" of the SG damage the CBA IV? If the CBA IV is clamped to the battery getting charged, disconnecting the output of the SG may hurt the transistors if the neon bulbs don't protect them but nothing will happen to the CBA IV. At least, I don't see how it will be damaged.