Shunt mod gains

anon4

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My controller is 13 amps, I believe my battery is rated 19 amos. Is there much to be gained from soldering the shunt or is it marginal difference?
 

Fordulike

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Feb 26, 2010
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You won't gain any more top speed, but you will improve hill climbing performance and the ability to maintain speed over undulating terrain. Don't expect miracles with a 13 amp rated controller though.

Best to add a small amount of solder, then test. Some controllers don't like it if you go too far with the solder.
 

anon4

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May 9, 2017
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You won't gain any more top speed, but you will improve hill climbing performance and the ability to maintain speed over undulating terrain. Don't expect miracles with a 13 amp rated controller though.

Best to add a small amount of solder, then test. Some controllers don't like it if you go too far with the solder.
Doesn't matter, I already tried it and it went boom! :D On closer inspection looks like a rogue blob dropped down and shorted the whole thing out, oops! :D:D:D
 
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Fordulike

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Oops :eek:

New uprated controller is the way to go. Maybe 20 amp rated with your battery.
 

anon4

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Oops :eek:

New uprated controller is the way to go. Maybe 20 amp rated with your battery.
I think 20 amp would trip the BMS. I only wanted to go like 15/16. Saying that some are configurable. I also need it to be pretty small. Have a basic spare without display that has thankfully fired up once I figured the wiring so at least I have power...
 

Nealh

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Which make of controller / LCD are you using.
 

Nealh

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KT lcd3 and controller will set you back about £80.
You can buy the cheaper lcd1 or 2 but the 3 gives you more parameters to fiddle with and one of the important ones is controller amps, you can adjust them down ( approx. by 5 amps) to suit your needs so no worry if you get a 17 or 20a controller and don't need all them's amps.
 
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anon4

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May 9, 2017
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I've just went for the same one because it's cheap and can take a 48v. If I decided to mod the shunt is there any way I can guard from this happening again? Something to catch any drip? More likely after this experience I'll just wait until I can get a 48v battery
 

Nealh

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If I decided to mod the shunt is there any way I can guard from this happening again? Something to catch any drip? More likely after this experience I'll just wait until I can get a 48v battery
Go easy on the solder use a thinner core solder, with the lid off and proper access try a bit of kitchen towel to prevent drips /splatter affecting other components or tracks. Add a bit try it/ride it & add more if needed to max of 25/30% of shunt, typically solder the rhs leg of the shunt on the v- away from the fets side of the controller.
Show a pic of the shunt you modded so we can see what/where went wrong.
 
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anon4

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May 9, 2017
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Go easy on the solder use a thinner core solder, with the lid off and proper access try a bit of kitchen towel to prevent drips /splatter affecting other components or tracks. Add a bit try it/ride it & add more if needed to max of 25/30% of shunt, typically solder the rhs leg of the shunt on the v- away from the fets side of the controller.
Show a pic of the shunt you modded so we can see what/where went wrong.
I've chucked it. Basically a bit dripped onto the base of the shunt that I didn't see and it shorted out against some tiny component that was under it, melting a hole though the board