Charging System for Cafe

Fchb25

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Hey guys,

I’m in the middle of a Cafe build on my 77 xs650. I’d like to keep all my stock options (headlight, taillights, turns, push button start, speedo, etc.)

I was looking into upgrading my charging system to the PMA style from TCBros (link below). Could I then run an 8 cell antigravity battery (link below) and keep all my stock options?

Pic for interest 😂


http://www.tcbroschoppers.com/xs650-permanent-magnet-alternator-kit-pma-fits-all-years.html

https://antigravitybatteries.com/products/starter-batteries/small-case/ag-801/
 

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I would say a PMA is a downgrade rather than an upgrade. Unless your OE charging system is missing, I would fix rather than go to aftermarket parts.
PMA makes current regardless the demand. Unused current is dissipated as heat.
The OE alternator responds to demand.
 
Thinking out loud
It can be an expensive way to get starting problems ..
I suppose you have points and stock old wiring
Downsizing the battery and aspire to use electric start can be a Dream and lead to kick starting or no starting.
 
Thinking out loud
It can be an expensive way to get starting problems ..
I suppose you have points and stock old wiring
Downsizing the battery and aspire to use electric start can be a Dream and lead to kick starting or no starting.
Yes it’s all stock wiring. I know a lot of guys opt to go kickstart only, but I figured I’d try and keep everything that’s currently there if possible. But if at the end of the day the push start is what’s throwing the wrench into the plans it can go. The battery is actually a higher CCA at 240 than the stock battery (or at least the 190 CCA mine had in it)
 
I would say a PMA is a downgrade rather than an upgrade. Unless your OE charging system is missing, I would fix rather than go to aftermarket parts.
PMA makes current regardless the demand. Unused current is dissipated as heat.
The OE alternator responds to demand.
Oh okay, yeah the video on their site made it seem a lot more of a sound upgrade with no wearable parts and a higher power output and more efficient charging.

And my current charging system works fine but I have read that you aren’t supposed to use stock reg/rect with an antigravity battery that it’ll toast it so I would have to upgrade. I just don’t want to get stranded anywhere lol.
 
Oh okay, yeah the video on their site made it seem a lot more of a sound upgrade with no wearable parts and a higher power output and more efficient charging.

And my current charging system works fine but I have read that you aren’t supposed to use stock reg/rect with an antigravity battery that it’ll toast it so I would have to upgrade. I just don’t want to get stranded anywhere lol.
You should change the regulator/rectifier to go with the new tech battery. If it's just an AGM, the antique regulator might be fine. If your charging rotor is original, it will leave you stranded for sure due to 1977 wire insulation technology. $100 will get it rewound and you'll never have to worry about it again. My stock charging system has 38 years and 61,000 miles on it. My rotor was rewound in 2002. I've had no other issues other than battery replacements. The stock system requires a healthy battery.
 
Oh okay, yeah the video on their site made it seem a lot more of a sound upgrade with no wearable parts and a higher power output and more efficient charging.
Brushes. The stock system has brushes. Every once in a while, you check them. Sometimes they get replaced due to the wear limit. I think the stock alternator put out up to 17 amps, IIRC. That's more than enough to run your lights. How much do you need? If the PMA has more output, the field (permanent magnet) can't be controlled, so max current output is what you get all the time. It's gotta go someplace. They need a big heat sink in the wind, and best you use as much of that current as possible. The stock rotor (magnetic field) is fed current from the battery through the voltage regulator. How much is determined by the demand. It's a nice system on a low price point motorcycle.
 
Yes, the PMA is definitely no upgrade in my opinion, just a different kind of charging system with it's own unique problems. They have been used for many, many years on motorcycles, but from a big factory, they have better components. That's the problem with many of these 650 kits, they have cheapo Chinese components that don't hold up. Like the regulator. On a PMA system, it works by converting the unused current to heat. The cheap regulators can't handle that for long. You can buy a good replacement but it can set you back $100. Now add that to the $300 or $400 you just paid for the system and you see why I think "PMA" stands for Piss Money Away, lol.
 
You should change the regulator/rectifier to go with the new tech battery. If it's just an AGM, the antique regulator might be fine. If your charging rotor is original, it will leave you stranded for sure due to 1977 wire insulation technology. $100 will get it rewound and you'll never have to worry about it again. My stock charging system has 38 years and 61,000 miles on it. My rotor was rewound in 2002. I've had no other issues other than battery replacements. The stock system requires a healthy battery.
So to recap before I purchase, with a new style reg/rect, a rewound rotor, and an 8 cell (240 CCA) antigravity battery I should be fine running all the stock electrical including the push button start?
 
So to recap before I purchase, with a new style reg/rect, a rewound rotor, and an 8 cell (240 CCA) antigravity battery I should be fine running all the stock electrical including the push button start?
Yes. I think what you need is a lithium compatible regulator/rectifier. That is true as long as I understand the battery you’re speaking of. My cousin runs a Shorai battery on his XS1100 with one of those regulators. (The battery is very small). It all seems to be working fine for a few years now.
 
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