What's involved in increasing voltage?

[CGameProgrammer]

I wish to upgrade to 72V from my current 48V. Obviously this means using six 12V batteries in series, and a 72V controller, and I know my X5 motor can more than handle it, but is there anything else that needs to be done? Like, I have a 48V Soneil charger. Can I still use it for charging the 6 batteries in series, or do I need to split them up first?

 

[xyster]

I wish to upgrade to 72V from my current 48V.

He's hooked already.

Obviously this means using six 12V batteries in series, and a 72V controller, and I know my X5 motor can more than handle it, but is there anything else that needs to be done?

Be aware that some 72V controllers have been dying at 72 volts nominal even though the components are ostensibly rated for at least 100V. Mine's been fine at 84 peak volts, which is about the voltage of 6, 12V SLAs in series hot off the charger.

Like, I have a 48V Soneil charger. Can I still use it for charging the 6 batteries in series, or do I need to split them up first?

You can use the 48V soneil to charge 4 of the 6. Buy another 24V charger of similar amp rating to charge the other two. The Soneil I believe is isolated already, so charging can be conducted simultaneously (you don't need to disconnect the 4-battery bank from the 2-battery bank for charging -- just make sure the wiring to the chargers is correct).

 

[CGameProgrammer]

Be aware that some 72V controllers have been dying at 72 volts nominal even though the components are ostensibly rated for at least 100V. Mine's been fine at 84 peak volts, which is about the voltage of 6, 12V SLAs in series hot off the charger.

I know; I'm not even going to plug the charger in without first attempting the FET substitutions knoxie detailed in his thread.

You can use the 48V soneil to charge 4 of the 6. Buy another 24V charger of similar amp rating to charge the other two. The Soneil I believe is isolated already, so charging can be conducted simultaneously (you don't need to disconnect the 4-battery bank from the 2-battery bank for charging -- just make sure the wiring to the chargers is correct).

Can you be more specific? My kit was actually pre-wired as shown in these instructions (PDF). It's obvious how to use two extra bits of wire for 6 batteries in series, but it's not obvious to me how to wire an additional charger port.

 

[Ypedal]

Is your throttle an LED type with battery gauge ? Those babies are voltage specific. The Non-Led type are ok at any voltage.

 

[xyster]

Is your throttle an LED type with battery gauge ? Those babies are voltage specific. The Non-Led type are ok at any voltage.

True. There's a fourth throttle wire on the LED gauge throttles that can be cut if using the higher voltage -- which is a good idea because this fourth wire has been the root of some dangerous WOT (wide open throttle) faults.

Can you be more specific? My kit was actually pre-wired as shown in these instructions (PDF). It's obvious how to use two extra bits of wire for 6 batteries in series, but it's not obvious to me how to wire an additional charger port.

Here's a diagram hack from your manual for wiring the extra port (I left out the fuse which can be wired between any of the batteries):

 

[xyster]

Also, be careful... a jolt of 72V DC from those batteries can weld metal, and be fatal to us mere mortals. If you do this, to reduces chances of a day-ruining mistake, I'd make wiring the 48v set to the 24v set the last step, and consider wearing gloves, having a dry work area, removing jewelry/watches etc...even 48 volts can give quite a jolt, so these are always good safety policies.

 

[TylerDurden]

72V DC from those batteries can weld metal, and be fatal to us mere mortals.

Only the Emperor has such mighty powers that even megavolts are triflings.


Just don't ask to touch his big capacitor.


8)

 

[Mathurin]

Excessive manipulation of the Emperor's big capacitor may result in sudden discharge!

 

[xyster]

Excessive manipulation of the Emperor's big capacitor may result in sudden discharge!

Not to worry. Most likely, recharging takes much longer than it used to, so Mathurin and Tyler have a window of safe opportunity. :lol:

Did I just say that?!

My dad always warned me to 'think before you speak'....

 

[Reid Welch]

I always thought gayness was inborn.
Wrong. Evidently caused and spread, contageous, by straight guys horsing, read above.



On second thought, do not read their postings, better not.



Me? I'm pure DC, and always at lov woltage.




Chechov