12V generators and Li batteries

[sharkoilfield]

I'm piecing together components to add electric start to my 1974 XLCH and a major lithium battery store tells me they've had problems when used in bikes with 12V generators.  Is this more due to primitive stock regulator or what?

[Appowner]

Hated the E-start on that era of Sportsters.  I went so far as to convert my 77 Sporty to kick.  With a SU carb I never had to kick more than 3 times.  Still miss that bike even though I couldn't start it today.

Generator or alternator, my understanding is once it makes it through the regulator the output should be the same.  Assuming the regulator is a modern solid state type.

I'd contact one or more of the Li Batt manufacturers directly and ask them.  I know Anti Grav is good about responding to questions. 

[smoserx1]

I'm having trouble understanding that too.  I'm not an electrical person but do think I read a generator has a commutator that reverses polarity to keep the wave positive so a rectifier is not needed, but what other difference is there?  How would the battery know?

[motorhogman]

Don't know about the generator vs alternator making any difference but I know my friends shop up in MA has seen a couple of cases of these batteries smoldering and one imploded. In every case it was a defective regulator overcharging not a defective battery..
  His advise, make sure your charging system is working properly before installing..

[sharkoilfield]

I'll be using the Tech Cycle starter; along with a Li batt...both will be much more "discreet" looking and more modern than the massive ancient original components. Maybe I need to add a modern regulator too? I see them on the end of the stock generators...I certainly will check with Li battery makers this week; good advise there

[Admiral Akbar]

A buddy has about a 69/70 sportster that is setup to look like and late 50s.  It's got a LI battery but has a Cycle Electric generator with a special lower output voltage solid state regulator mounted on the end of the generator. While it don't have electric start, the LI battery seems to be surviving.   IIRC he said it was only 13.1 volt output.  Might want to give CE a call and ask them.  Knowing the old mechanical relays, the max output voltage is all over the place.  I'd bet you have to go solid state.

[sharkoilfield]

I've emailed both Shorai and Anti-Gravity inquiring about using their batteries with stock 1974 charging system. I'll check DS tomorrow for Cycle Electric products...

[xlfan]

Since the lithium batteries requires special rate chargers, I would be surprised if they didn't require a special rate regulator on a bike charging system as well.

[kd]

The special rate chargers are used to bring a battery back from a low state of charge or as a tender when you have clocks, security, LoJack, etc...  You would be amazed at how high the charge rate is. My Ultra will feed well over 14 volts into my AG battery with no ill effects.  In fact how hot the charger / tender will get if the battery is very low will surprise you but is designed to do it that way in steps.  The motorcycle and auto charging systems are compatible or what would be the point?  AntiGravity has just up dated their site and address the motorcycle charging / regulators.  Max nailed it with the solid state regulator being a wise choice over the mechanical because vibration can make the mechanical regulator be inconsistent.   You may have blown bulbs over revving a sporty with a mechanical unit.

I have commented lots on AntiGravity batteries in the past.  To be clear, I have no connection to them other than I do spend time at their booth at SEMA with enquiries and have spoken to their tech folks several times on the phone and on-line to make sure I knew what I was doing before I did it.  I chose to use their batteries and other products over others because this is all they do.  I find them to be leading the pack for the most part and able to advise on the best way to go.  (I have compared them to others at SEMA and found them to be heads above with products, information and knowledge)  FYI, they clearly state their products have been extensively tested using OEM vehicle charging systems and warranty their batteries based on them being used that way.  We all seem to agree  There are some vehicles like Harley, the CE offerings seem to be superior but they have not tested them and that could jeopardize the warranty.  I suggest going to their website for info and explanations and calling them when you don't find what you are looking for.

[sharkoilfield]

Anti-G responded quickly; said they were passing my question on to tech
Haven't heard anything else.
Shorai responded saying charging should be 13.4-14.2 V  THROUGHOUT the bikes operating rpm range; if lower, than upgraded charging system required.
Pretty concise answer...

[Appowner]

I too heard from AG on this matter of using generators with AG batteries.  Here's what they said to me:

"Thank you for reaching out to us.
As long as you upgrade the voltage regulator to a solid state unit, it will work. We recommend the 14 V setpoint, but anything between 13.4 and 14.4 V is also fine."

[sharkoilfield]

Sounds like consensus between the two major manufacturers. Now to research voltage regulators; I see stock appearing from Accel and the end of generator device from Cycle Electric. Will check specs, price & availability in Canada