NiCd projects

[Bruce S]

Fellow NiCd'rs

 With some very nice postings from Zap and Norm about those very nice NiCd packs.

I thought it might be time to post an update of a little project a neighbor & I have been working on.

This it be. Not much, but works like a charm. the specs:

12Vdc 26Ahr. There's 20 of the stacks hot glued and wired up in total there.

BTW: This is replacing a 12Vdc 18Ahr SLA that weighs 21.5lbs this weighs 14.2lbs.

We decided that after looking at the wire guage references for both 14ga and 12ga, that we could purpose build a couple of these.

This one uses 14ga solid wire straight out of trashed house wiring "Romex" & we all know free is great.

with a little rewiring it has been able to rum the little e-bike rated at 48Vdc, but we didn't go far due to wire rating

This will however fire up a nice MSW 800watt inverter, but a cute little 150watt will run a whole back yard of LED string lights or a couple 110Vac fans.

UPDATE!!





For those of you who have the batts and have this little gem.

If for some reason you have gotten the batts to over heat OR are losing power for no known reason. Cut this puppy out and solder the connections together, or replace it with same.

Seems that once they've popped once they become very unstable.

I have been able to recoop 1/2 dozen 6v packs so far by remove this and retesting.

Cheers

Bruce S

[ghurd]

I was a bit skeptical at first, but then I saw both "free" and "hot glue" mentioned.

They are 2 my most favorite 4 things.

G-

[Bruce S]

Hey G-

Yup, dual heat hot glue is a wonderful thing :-) 'cept when it's burning the skin as it cools.

I'm working with your soon-to-be famous dump controller as a LVD for this and it's twin.

What can't be seen nor included in the original post was a couple of the thermal probes that come with "some" cheapo DMMs.

The last time I didn't take care the pack exploded in the middle :-( outwards during test charging, so we're playing safe.

Zap: this is a test pack designed for the currie motor as well.

Couldn't help plugging in a few "test" inverters and trying out the "kewl!!" factor when it was finished and it got dark enough to turn on the lights.

[zap]

That's nice looking Bruce.  I want to see some distance/speed comparisons.

It really looks like a dirty bomb now.

That's interesting on the thermal cutoffs.  I charged my pack off the solar using one these.  I didn't mean to leave it unattended but a trip with a friend turned out to be longer than I thought.  When I returned, the first thing I did was look at the charger and it was still flashing so I reached down and felt the pack.  It was hot so I disconnected everything right away.  It wasn't so hot I couldn't touch it but it was hot.  I think those thermal cutoffs are 200F and I really don't think this pack was 200F.  The pack seems to have lost some power but I haven't checked it out real well yet.  I guess I'll have to dig into it and test those cutoffs.

Side note:

I took the Currie drive and motor off one of the folders and put it on my beater bike.  The motor is laced up to a 26" wheel now and it looks like the max speed without pedaling is right around 15.5mph  I haven't done an endurance test yet and I need to get another pack built to even out the weight since the existing pack resides in the right hand pannier now instead of centered over the wheel like it was on the folder.

Bruce are you going to use a "Straight" Currie or are you thinking of overvolting one?

[Norm]

Nice goin' looks like the 'ol 'tab ends curled

around the wire' trick, eh?

One of the first things on disassemblys...cut the

little 'puppys' out !  

The way I figure the wire rating is really more

than adequate...it's right after it leaves the

battery....and not even then at 48 volts.....

 

[Bruce S]

Zap;

  I plan on using a straight currie drive. Have an older single speed Ladies bike that I will be using. I've overvolted before, but it works, but it does lessen the life of the motor and since this will be for the wifey to go back & forth to work !!! gotta be safe, scure, and stylish.

It's cute too has the front basket, 26inch balloon sized tires and all :-).

Tons of room for the batts to be on the back. I'm planning on 2 of these for balance and distance.

As you & Norm know, even with the hot glue, these can be a bit unstable, so we'll be using marine battery boxes to hold these in, or something as sturdy.

Of those of your that over heated, they should come back to mostly okay, check the vents on the top, if they vented then they will surely have gotten to hot, but will still work.

I have a minor test of these. I have a 12V pack that gave me a error code that meant "0" capacity; I cut the thermal of and retested the packs as 6V individuals for the entire weekend ( put the tester in Lifcycle mode) it came back up to 89%, which is phenom, but suspect for me , so I have them back on the tester with full test; will let you know.

dirty bomb, yea I know:-) I get those "looks" when people see them siting around.

Cheers

Bruce S

[Bruce S]

Hey Norm;

 Gotta give credit where credit is due!! Its was your posts on how you wired them up and wrapped the tabs!! that helped us with the heavy duty idea.

We haven't gone so far as cutting the thermals out. If the pack tests okay, I like having a little extra safety :-)

Doing some math for wiring up a 24V motor and distance plus cooler weather. For the Currie bike we'll probably go with 12ga as intra-batt connections and use same gage stranded wire for battery to motor and pot connections. The stranded wire is much easier to work with and easier to find, think chewed on extension cords [.

Having Fun!!

Bruce S

[Bruce S]

Zap;

   Question on that inverter? How's it stand up? that seems to be a nice portable one. Would seem to be a better fit for traveling with on a bike.

Bruce S

[zap]

So far that inverter is rock solid.  It seems to put out a nice clean signal too, I've used it on the stereo and a boom box without any discernible hiss or static and a 21" Phillips crt/tv seems to have a perfect picture.

It pulls around 250ma at idle since the fan runs constantly.  No Off switch but has a low voltage reset button.  Low voltage shut off is 10.25 vcd on mine.

At $8 on clearance I would have bought a case of them if they had that many.

[Bruce S]

Zap;

  That is a good price!

More than a little worried about the LVD settings though.

At 10.25Vcd that too low for the NiCds; the cutoff if you can adjust should be right at 12.0 that's safe for them to drop to ~85% of full charge, lower and you can run the risk of one of the Sub-Cs going to zero or worse, reverse voltage and take the entire pack down.

I'll have a look around to see if I can find a few and open one up for a look too.

Have Fun

Bruce S

[zap]

Yup, I don't care for the lvd but I'm usually using it with an old, tired 8ah sla while I'm on the pedal generator powering the TV or stereo so that low voltage hasn't bothered me yet and it's easy to keep an eye on it.

I took the ebike for a ride the other day and hooked that inverter to the battery bank to charge the bike back up.  I decided to use the older, transformer based charger and see how it did.  It seemed to do OK but I went to check on it and something had shut the inverter down and it was singing an alarm.  I know it wasn't lvd because that bank is about 200ah and the SG4 was pumping in power at the time and the inverter wasn't warm at all.  I have no idea what it was but pushed the reset and it started up again so???

I opened it up after I first got to see about setting the fan up as a thermal fan but... my days of messing with circuits is well behind me I think.  I have no idea how to do that or how to change the lvd.  If I had an extra one sitting around I might mess with it but since it's not really broken I've let it live... for now!