jd750ace
Front Toward Enemy
I'll see what I can find for possibles, but you may have to get into spending more than 15 bucks to get the reliability you're looking for!
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PMA question, battery or condenser
- Thread starter shark1979
- Start date
jd750ace
Front Toward Enemy
http://www.ebay.com/itm/New-68000uF...ps=63&clkid=256403132738564111&_qi=RTM1062692
This one matches the numbers given above. It's probably bigger too, but Dangit, regardless of what they tell you in therapy, sometimes size DOES matter!
This one matches the numbers given above. It's probably bigger too, but Dangit, regardless of what they tell you in therapy, sometimes size DOES matter!
JR Roxx
XS650 Addict
Pete is right about overcharging.. But I just bar hop on it and it's main use is turning on the neutral light (yep I've done it)
coughing skunk
XS650 Addict
Pete,
Please elaborate on this. I'm sure you know this but the purpose of a regulator is to prevent over charging, even with a strong output from the PMA, by transferring the extra energy into heat.
I'd be pretty shocked to see that the little batteries over charge with a properly working regulator. At least in my experience I have had no issues with a mini battery.
pamcopete
Ride.Enjoy.Life is Simple
coughing skunk,
The voltage regulator is a voltage regulator, not a current regulator. If the PMA is capable of producing 15 Amps, then you will have 15 Amps available at 14.5 Volts. If the rest of the system consumes 12 of those 15 Amps, the extra 3 Amps will be available to charge the battery or will be converted into heat in the regulator. The maximum charging current for a lead acid battery is 10% of it's Amp Hour Capacity, so for a tiny 8 AH battery, the maximum charging current is .8 Amp, not 3 Amps. This will only be a problem if the battery voltage is less than 14.5, which for a tiny battery is most of the time. A battery is considered to be discharged when its voltage drops to 10.5 Volts, which happens whenever you stop at a stop light for more than a few seconds with a tiny battery, so as soon as you start going again and the revs get up to 3,000, the spare amps will be going into the battery. because the 3 Amps is much greater than the rated max charging current, the battery cannot absorb them and instead converts the extra amps to heat, which literally boils the battery.
So, depending on your riding habits, you may or may not get away with using a tiny battery. It helps if you put the tiny battery on a tiny trickle charger overnight so that it starts each day fully charged. A fully charged battery will draw zero Amps, regardless of the availability.
These alternator systems were designed for a conventional 14 AH battery which would use about half of the extra 3 Amps from a typical PMA system. A standard sized battery would not drop to 10.5 Volts at a stop light, so when you take off again and hit 3,000 RPM, the battery is not going to get cooked.
Any electrical system is designed with all of the components included in the design process. You can't just jump in and say "I'm going to change this big ugly 14 AH battery for a 8 AH tiny battery because that's cool" without looking at the entire electrical system.
The voltage regulator is a voltage regulator, not a current regulator. If the PMA is capable of producing 15 Amps, then you will have 15 Amps available at 14.5 Volts. If the rest of the system consumes 12 of those 15 Amps, the extra 3 Amps will be available to charge the battery or will be converted into heat in the regulator. The maximum charging current for a lead acid battery is 10% of it's Amp Hour Capacity, so for a tiny 8 AH battery, the maximum charging current is .8 Amp, not 3 Amps. This will only be a problem if the battery voltage is less than 14.5, which for a tiny battery is most of the time. A battery is considered to be discharged when its voltage drops to 10.5 Volts, which happens whenever you stop at a stop light for more than a few seconds with a tiny battery, so as soon as you start going again and the revs get up to 3,000, the spare amps will be going into the battery. because the 3 Amps is much greater than the rated max charging current, the battery cannot absorb them and instead converts the extra amps to heat, which literally boils the battery.
So, depending on your riding habits, you may or may not get away with using a tiny battery. It helps if you put the tiny battery on a tiny trickle charger overnight so that it starts each day fully charged. A fully charged battery will draw zero Amps, regardless of the availability.
These alternator systems were designed for a conventional 14 AH battery which would use about half of the extra 3 Amps from a typical PMA system. A standard sized battery would not drop to 10.5 Volts at a stop light, so when you take off again and hit 3,000 RPM, the battery is not going to get cooked.
Any electrical system is designed with all of the components included in the design process. You can't just jump in and say "I'm going to change this big ugly 14 AH battery for a 8 AH tiny battery because that's cool" without looking at the entire electrical system.
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coughing skunk
XS650 Addict
Pete,
I've never put that much thought into the charging system since it worked. Thanks for the schooling.
I've never put that much thought into the charging system since it worked. Thanks for the schooling.
jd750ace
Front Toward Enemy
Outstanding explaination Pete! You a teacher? Or is this just a sermon you have preached before? (seriously, when I don't have to read it twice, I consider it very well written!)
Chi2
XS650 Enthusiast
Pete,
Once again we are in your debt for electrical enlightenment! While warning us about the dangers of small batteries and cheap caps, you have not indicated which capacitor would be useable with a PMA/Pamco setup. Do you have any recommendations?
Once again we are in your debt for electrical enlightenment! While warning us about the dangers of small batteries and cheap caps, you have not indicated which capacitor would be useable with a PMA/Pamco setup. Do you have any recommendations?
Thats the question. Which capacitor or small battery works with PMA and Pamco. I have heard so many reports both ways on this subject. I don't have an electric start, turn signals, and am not required to run with lights on in daytime here in Arizona. I don't ride at night much at all anymore so headlight isn't an issue. I finished the bike and have put a little less than 100 miles on it with the smoke pack sized battery and everything going good so far. I am just wondering long term.
jefft
Posted via Mobile
jefft
Posted via Mobile
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pamcopete
Ride.Enjoy.Life is Simple
Your type of riding will probably be OK with a tiny battery because as I understand it, you do not have a headlight on during the day and you do very little night time riding. Without the headlight drawing current from the tiny battery at the stop light, the tiny battery probably does not discharge very much when stopped so when you get to going again and hit 3,000 RPM, the tiny battery will not draw destructive current but will just quietly get recharged.
Another way to achieve this balance of current draw vs recharge current is to rig a relay to turn off the headlight when in neutral and install LED tail lights so when you are stopped at the stop light the tiny battery will not be discharged.
JR Hammer
XS650 enthusiast
Hey Pete--- thanks for covering the battery issue in detail... I ride with lights on and just wired up my tiny battery about 100mi ago. It seems to be holding it's charge now that I have put a switch on the system that can turn the whole thing off when I am not riding it, but now I am becoming sceptical after learning about the issues associated with overcharging.
So could you give an example of a good capacitor to use? If the ACCEL battery eliminator is just cheap chit what would be more appropriate?? I found a couple 6000uF 50vdc caps at the local electronic surplus dealer but have not tried them yet
So could you give an example of a good capacitor to use? If the ACCEL battery eliminator is just cheap chit what would be more appropriate?? I found a couple 6000uF 50vdc caps at the local electronic surplus dealer but have not tried them yet
Agreed Hammer, I think that is what most people are waiting to here about is a proven, reliable capacitor that works with the PMA. I didn't have good luck with the Accel. One member suggested it was the amount of money you spend on a good capacitor. Well, that Accel was about $40.00 as I remember.
jefft
Posted via Mobile
jefft
Posted via Mobile
Emilws
XS650 Member
Hey jeff,
I have the EXACT same problems with that .8 ah battery and my PMA system. I am now on to my second one. I am off to try a capacitor now, but the thread did not come up with specs and recommendations.
Which one did you end up using and what are the electrical specs for it?
I just bought this one:
https://www.kickstartershop.de/en/BATTERY-LESSER/ELIMINATOR-SR500/SR-500-SRX-XL/XR/XT-600-uva-
Not sure of the specs yet, but is was only 23$.
https://www.mikesxs.net/capacitor-kit-for-xs650-pma-charging-system.html
I see that MikesXS has one, but as I am located in Europe, so that is too much of a hassle, and I don't know if it will work.
I run with the stock headlight, only speedometer backlit, no turn signals and a LED taillight. (Photo)
Emilws
XS650 Member
Never mind, I fixed it with the capacitor from kickstartershop and she runs like a charm! Like getting a new bike.
Goodbye battery graveyard...
