Trail Battery Eliminator, it is possible!

[FizzBuzz3000]

In order to not ruin @Cursivealpha's thread any further (sorry about that, I hope you can forgive me ), I wanted to move discussion of the battery delete here to make a discussion to see if it's even viable.... And if anyone has done it!

So, what is a battery delete/eliminator? It's a method used for older, kickstart (usually carbeurated) bikes to not depend on a battery for startup and operation. It ensures reliability and saves a small amount of weight. It uses a capacitor in place of the battery to ensure a complete connection happens within the bike to power everything (though normally it was just lights for those bikes) and smooth out the bursts of power from the generator. There are some very big obvious downsides: No lights unless the engine is running, and you gotta kickstart/rollstart the bike! So it's definitely only for those crazy clever enough to do it.

So as far as we know: The Trail can run on its own without a battery, meaning is has separate magneto ignition that the ECU and spark-plug are attached to. Not sure on the fuel pump. Supplied with the trail is also a kick starter this makes a battery delete *very* possible! What is needed to find out is what size capacitor(s) are needed to ensure the bike is fully operational with lights/speedo, ABS and possibly the fuel pump. An electrical diagram would help a lot and I do have a service manual on its way here so I can at least check it out. For now, I have no real intentions to do this (I'm not knowledgeable to do it), but I would still at least like to get it out there. I would love to see if someone is able to pull it off and give purpose to the kick starter! Might just make me do it...

 

[dmonkey]

You can find a JA55 service manual in this thread with the wiring diagram at the end of the manual.

A slight clarification - the bike does not have a separate magneto ignition. It has a stator and rotor setup that uses a regulator/rectifier to convert AC voltage to DC voltage. The combination of the stator and regulator/rectifier function as an alternator. The alternator and battery (if present) power the ignition system as well as most of the circuits on the bike. The headlight hi/low (but not PO/position light/parking light) circuits are powered directly off the reg/rec without making use of the battery even if it's present.

 

[m in sc]

Battery Eliminator / Capacitor - Hughs Hand Built

Battery Eliminator / Capacitor For PMA or HHB CDI Equipped Motorcycles Anti Vibration Spring Mount Quad Terminals for easy install 12V Systems ONLY

www.hughshandbuilt.com

 

[Daytripper]

This is a good discussion topic for me as I find replacing these tiny lead acid batteries to be frightfully expensive and when (not if) the batt goes on my Trail I would seriously consider ditching the battery altogether, so long as I wouldn't be introducing problems to the electrical system or EFI. As for the ABS I hear it doesn't work properly without the battery? This is going into my 6th decade riding motorcycles and I have by now learned just how much brake I can apply front and rear wheels in order to not lock up the front wheel. Unless I try quite deliberately I never activate the ABS at all. I think the reasons it is there probably have more to do with various world highway safety standards than any actual need. I can see it on a car where a driver has no control over the percent of braking applied to the front and rear which is baked into the car, but that is not the case with MC's.

My last bike, a Kawasaki Sherpa went through 3 batteries. It had no kick starter, and was hard starting, a problem I never got fully resolved. I remember 20 years ago a new battery was around $175. I am scared to ask how much it costs for the Trail.

I ran a Kawasaki 4 wheeler with a 220CC without a battery for probably 15 years. I never got around to replacing the dead battery and it worked fine, the headlights did dim more however when at idle. I finally strapped on a $60 Napa "lawn and garden" batt on the rear rack and extended the leads to it so I could use the electric start as that recoil starter started killing my arthritis.

 

[BoonDonkey]

< I remember 20 years ago a new battery was around $175. I am scared to ask how much it costs for the Trail. >

$80-$145 (lead acid to lithium) at RMATVMC
I would not consider running any modern motorcycle without a battery, even if it has a kick starter. It has fuel injection and an ECU. Proper voltage is important.
It's cool that the Trail 125 has a kick starter. I use it for the first start of every ride and it usually starts on the first kick. I consider the kick starter to be an emergency back up to a "dead" battery, not a substitute for "live" battery.

 

[m in sc]

it'll be fine with a capacitor, the point is to stabilize the voltage . that acts as a buffer and the regulator regulates it. zero harm.

 

[Daytripper]

$80-$145 (lead acid to lithium) at RMATVMC
I would not consider running any modern motorcycle without a battery, even if it has a kick starter. It has fuel injection and an ECU. Proper voltage is important.
It's cool that the Trail 125 has a kick starter. I use it for the first start of every ride and it usually starts on the first kick. I consider the kick starter to be an emergency back up to a "dead" battery, not a substitute for "live" battery.

Got excited there for about 10 seconds, until I remembered where I live.

 

[SneakyDingo]

Oh, it's on sale! **yoink**

 

[FizzBuzz3000]

My JA65 service manual came in today, and it's quite interesting, if I am reading it right: The starter has a direct and is the sole link-up to the battery.

Everything else has some form of getting its power off of the regulator-rectifier and does not interact with the battery at all, or only uses the battery as a capacitor to take some additional charge/smooth the voltage from. I'll see if I can upload some pics tomorrow/on the weekend so everyone can get a good look. I don't think you need that large of a capacitor if you plan on not using the starter at all...

 

[m in sc]

no battery no starter, capacitor won't turn it, obviously. better to oversize a cap on a bike than undersize it. tgings like.. the brake light, turn signals, etc will def work smoother with a larger capacitor. it will reduce the spiking/drop of voltage. the one I linked will work just fine. 0.02.

 

[dmonkey]

Everything else has some form of getting its power off of the regulator-rectifier and does not interact with the battery at all, or only uses the battery as a capacitor to take some additional charge/smooth the voltage from.

hi/low headlight = alternator power only
Starter = battery power only
The rest seem to use both

The battery stabilizes the voltage and acts as a voltage reservoir. The regulator/rectifier is "SCR opened/single phase, half wave rectification" which means it only passes the positive half of the AC waveform, so the DC output would pulsate even though the regulator may smooth it out a bit. You can observe that by watching the headlight flicker at low RPM.


https://www.rohm.com/electronics-basics/ac-dc/rectification

 

[FizzBuzz3000]

Yeah. After looking through more diagrams in the manual, the battery supplies the rectifier with the additional missing DC voltage to keep it constant (through the red-yellow wire). Thanks for clarifying! Helped me see how the flow of the wiring diagram goes.

 

[m in sc]

my grom with a 1985 suzuki LT250 quad motor is still using the stock harness/rr gauges from the grom, but the original 1985 suzuki alternator/cdi setup. It indeed will run everything on the grom (stock) with a battery or capacitor. the charging system is almost identical grom to trail (also half wave) , so i have 1st hand experience here. it'll work fine. did the same thing on my lightweight RD (capacitor) and the harris moto GP bike im working on, i just added a charging system and going half-wave as well. I choose to run a battery on the grom but have done it both ways. There is of course only a kickstarter on the quad motor.

 

[Cpd419]

This is a good discussion topic for me as I find replacing these tiny lead acid batteries to be frightfully expensive and when (not if) the batt goes on my Trail I would seriously consider ditching the battery altogether, so long as I wouldn't be introducing problems to the electrical system or EFI. As for the ABS I hear it doesn't work properly without the battery? This is going into my 6th decade riding motorcycles and I have by now learned just how much brake I can apply front and rear wheels in order to not lock up the front wheel. Unless I try quite deliberately I never activate the ABS at all. I think the reasons it is there probably have more to do with various world highway safety standards than any actual need. I can see it on a car where a driver has no control over the percent of braking applied to the front and rear which is baked into the car, but that is not the case with MC's.

My last bike, a Kawasaki Sherpa went through 3 batteries. It had no kick starter, and was hard starting, a problem I never got fully resolved. I remember 20 years ago a new battery was around $175. I am scared to ask how much it costs for the Trail.

I ran a Kawasaki 4 wheeler with a 220CC without a battery for probably 15 years. I never got around to replacing the dead battery and it worked fine, the headlights did dim more however when at idle. I finally strapped on a $60 Napa "lawn and garden" batt on the rear rack and extended the leads to it so I could use the electric start as that recoil starter started killing my arthritis.

I bought a battery off of eBay for the navi for about $20. Been rock solid for about a year.

 

[Daytripper]

I bought a battery off of eBay for the navi for about $20. Been rock solid for about a year.

Biggest obstacle for me is shipping to my town in Alaska where the USPS won't accept batteries over a tiny size. There are some ways around it such as UPS but usually makes the shipping way more than the product itself. Anyway, the battery in my 24 Trail is good, and I just installed the wiring harness to plug in a tender so we'll see how that goes. I would rather have a battery than not, but if I get in a bind and can't get a new one when this one dies it is good to know that I can run it without, by using a cap in the battery leads. Pretty slick!

 

[FizzBuzz3000]

I got a capacitor on its way, well will see sometime in november if there's a warm day

 

[FizzBuzz3000]

And the results are in: It works! The ABS, speedo, horn, and rear/turn lights work! The bike started right up on the 3rd kick after the capacitor got enough juice to allow the ECU and fuel pump to run. There is some minor flickering with rear light, but I think that has always been the case. The bike instantly dies after it is shut off and turned back on, which is no biggie. It started right up on the first kick after the bike was warmed up.

The capacitor I am using is a 40,000uF Sprague 36DE 25V Capacitor that I got as a two-pack for ~$30 total off of ebay. I and going to make this setup a bit more SC-resistant by making some leads to go off of the capacitor itself. I'll also make a proper housing for the capacitor as well, but it works fine for now! There's also a need to test for longevity, so I still wouldn't fully recommend it quite yet.

 

[Daytripper]

Can you put a DC volt meter on the leads to the cap? I am curious about my USB phone charger... Hate to blow up my smart phone ya know!

 

[SneakyDingo]

Phones are particularly sensitive to charging, especially if you have an iPhone[1]. If you were worried, I'd run it to an intermediate, like a wireless charger or a battery pack that supports through charging. The wireless one is especially good as it completely decouples, as well as will continue to work even if the charging port gets wet.

[1] they routinely mess with the charging algorithm and have very little in the way of testing; they've disabled and then had to roll back several times because of non-OEM charging support being lost; their most recent update broke my manager's phone too and resulted in him having to get it replaced.

 

[Daytripper]

Phones are particularly sensitive to charging, especially if you have an iPhone[1]. If you were worried, I'd run it to an intermediate, like a wireless charger or a battery pack that supports through charging. The wireless one is especially good as it completely decouples, as well as will continue to work even if the charging port gets wet.

[1] they routinely mess with the charging algorithm and have very little in the way of testing; they've disabled and then had to roll back several times because of non-OEM charging support being lost; their most recent update broke my manager's phone too and resulted in him having to get it replaced.

That's a great idea. Still have a good battery for now as my bike is a 24, but the day always comes when these little lead acid batts fail and I will have a cap ready when that comes.