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Discussion Starter #1
I'm putting my Cb72 back together and need a new battery. Running a dyna S with 2 Dyna coils, single plug head.Fires a waste spark. Smallest I've personally ever run is a 7AH battery. Buff used to run a 5AH, but I never did trust Buff and electrics (not after he came to Summit for the first time, pulled his tank and there was an extra 3 miles of wire stuffed under the tank-he didn't finish the race).

I tried looking on Dyna's site for power requirements, but couldn't find it. Whats the smallest anyone has ever used for total loss on a similiar bike (Cb160, 350, 450, etc)?

A sealed 7AH weighs 5.1lbs, a 5AH = 3.5lbs.
 

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I'd have to check the AH on the type I used to run, but it was about half the size of the CB160 battery and weighed in at about 3 lbs.

Doesn't Dyna have some pretty loopy requirements for voltage? Seems like they warn against dropping below 12v in a big way.

I know with the proper coil resistor you can run a pretty small battery. I'll be in the shop tomorrow and see if I can get a number off the battery.
JohnnyB
 

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Discussion Starter #4
its hard to get any real info from them, but below 12v the dyna seems to be a little unhappy. I run a dyna battery guage on the bike so I will know, but since I have to buy the battery, build a battery box and install it, it would be nice to have a clue before I find out 5 laps in that 5AH wasn't enough.

I got Dyna's tech number so maybe I will call tehm tomorrow-any chance they can actually help me?!
 

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I ran a small 12v scooter battery in a stock cb total loss setup. it worked alright.... I ended up running the stock sized battery since I had 3 of them.

Someday I will come down south to race. These days my pallet is very full with the 2 kids.

matt

latered
 

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Wrote down the number of my battery but left it in the shop....something like a sears 44014. Little thing about 4.5" x 2.5" x 4" tall. Acid type, with a blue top. They probably make a maintainance free equivilant now.
When I bought it I just went to sears and asked for the smallest 12v battery they stocked. Worked so nice I kept using them.

Now all the bikes are PVL...so no worries. Do some checking and find out what the highest rated resistor you can use is...that cuts down battery usage a lot...sends voltage instead of a bunch of current heating up the coil for no reason.

I've also heard of people running Dyna's on cordless tool batteries...they are like 14v, hold a good charge, charge up fast...and come with a neato charger. No acid, no vent required.
JohnnyB
 
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