Skorpion SP

[Bill Jurgenson]

I've updated the blog:
http://cembalobill.blogspot.com/

[droy]

Bill,

Some great stuff. Keep it coming.

[Bill Jurgenson]

I have updated the blog again, now that the bike is running and has passed inspection.
http://cembalobill.blogspot.com/2010/07/picking-up-from-last-entry-bike-is.html

[Old Dog]

Looking good Bill. I will be interested to see how long that battery lasts. Would be interested to see how long it would run the lights for on a wet dark night in west wales too

Will look forward to the performace and ride report mate.

[DAVID THOMPSON]

i like the battery
i recycled a 24 volt pack from a drill
i made it into 2 12 volt packs it is wired into the bike to run my ham radio gear
but with the flip of a switch it will run the cdi box and coil for about 45 min total loss
maybe more
i like back up systems on my ride
dave

[Bill Jurgenson]

not many miles yet since last wed. about 350-400mls
given that I always ride with the lights on, I'd say the little thing is doing fine.
the bike is getting better every day, too.
Still running in, tho.

[cat]

148, not bad.

I'm going to try the battery. I've got 10 cells I got a while ago, for doing Maglite mods. I must try to find out about amp output from the charging circuit..regulator/rectifier? Anyway, they can take some abuse, they don't burn. Reminds me, it's long overdue that I charged them. I hope they're still ok.

[billr]

148, not bad.
I'm going to try the battery. I've got 10 cells I got a while ago, for doing Maglite mods. I must try to find out about amp output from the charging circuit..regulator/rectifier? Anyway, they can take some abuse, they don't burn. Reminds me, it's long overdue that I charged them. I hope they're still ok.

Interesting to see how it goes. I would like to know about the charging rate/cut-off voltage for the stock system (haven't made time to check it).

Information from the RC world on charging the A123 batteries.
Gives some maximum voltage and charge rates.
http://www.slkelectronics.com/DeWalt/charge.htm

Bill R.

[cat]

The thing is, bike charging circuit doesn't have cut-off, it just trickle charges all the time (afaik), which is good for lead-acid batteries. The A123, even though they can handle a high amp charge, more than other Li types, the chargers normally have some cut-off system. So it means I need to find out on candlepowerforums how to build a simple cut-off circuit, to include in the pack. And that is basically why the few people trying to market these for bikes are able to do it, try to charge a high price for what is basically used Dewalt batteries - the addition of a simple cut-off circuit.

So I must get to that. But the first thing is to recharge them and check if they're still ok - they've been lying in my cupboard for more than a year.

[billr]

The thing is, bike charging circuit doesn't have cut-off, it just trickle charges all the time (afaik), which is good for lead-acid batteries. The A123, even though they can handle a high amp charge, more than other Li types, the chargers normally have some cut-off system. So it means I need to find out on candlepowerforums how to build a simple cut-off circuit, to include in the pack. And that is basically why the few people trying to market these for bikes are able to do it, try to charge a high price for what is basically used Dewalt batteries - the addition of a simple cut-off circuit.
So I must get to that. But the first thing is to recharge them and check if they're still ok - they've been lying in my cupboard for more than a year.

I was using a 5s2p pack in my model heli. It sat for almost a year and charged up fine. No degradation in performace at all.
I didn't need to worry about the cut-off switches (dedicated charger, adjustable speed control, etc), so I haven't searched for any template.
Lots of resources on a couple of RC boards I used to visit. I'll start digging and see what I can come up with.
Let us know if you come up with anything.
Bill R.

[cat]

Yes, please! I get to asking on candlepower forum in next week or so, hopefully, but...I don't want to get involved (and I don't want to look at flashlight pics or next thing I'll be buying them again!) ...just need a basic circuit to do the cut-off. I know the cheapo chargers don't do it properly, but the basic thing must be possible. As for how much it would cost, even if it is more than $5-$10 of components, just consider what a new UASA battery costs.

Yes! I put a couple of them on the charger last night, individually. It showed 3.37 V and charged up to 3.6 in about 3 minutes, at 3. I'm not going to bother checking how much they've discharged after a couple of days, because if that's all they've lost over a year or so, it looks like they're fine. (I've got a BC-6 charger - I'd got that because it had a program for LiFe. I just had to refresh my memory. I found that I had set up a profile to charge the A123.)

[billr]

...just need a basic circuit to do the cut-off.

I started a new topic on A123 Systems batteries that has a link to a DIY charge circuit.
Bill R

[Bill Jurgenson]

Haven't followed the LiFePo discussion further. My little battery is holding up just fine, tho.

Here a link to today's update of my blog where I also tell about test riding two different Vuns yesterday.