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Message started by Berzerker on 03/10/20 at 19:15:45

Title: R/R ?
Post by Berzerker on 03/10/20 at 19:15:45

I read on here that if u run a lifePo battery u should switch to IMHO mosfit R/R. I put an antigravity lithium battery in, so my question is do I need to change my R/R ? If so, what is a IMHO mosfit? Model?

Title: Re: R/R ?
Post by verslagen1 on 03/10/20 at 19:38:43

In my humble opinion... you read to much.

Title: Re: R/R ?
Post by Armen on 03/10/20 at 20:16:16

Get a digital voltmeter and see how high the bike charges. Suzukis run the highest charging voltage of any bike I've ever worked on. Sometimes as much as 15.5V. That high will blow up most lithium batteries.
Do the test, then shoot a note to AntiGravity and see what they say.
Or not.
Worst case scenario is the battery explodes and the bike catches fire.
Guess I'm a wimp.
I got mine (LiIo compatible R/R) from Ricks in NH.

Title: Re: R/R ?
Post by srinath on 03/10/20 at 21:10:12

Mosfet - Its a type of transistor. Its more robust than the diode based R/R on most bikes. I need an exact circuit with parts etc etc which no one will provide (as its a trade secret, and if I found the circuit, I'll make these at home) to explain what each does exactly - but a rough number set looks like this -
The diode based R/R cuts off the voltage and sends it to the heat sink as heat. It may make 100 watts at 14.7V. Past that its all heat, and the heat sink will get hot and you can feel it easily in a few mins of running.
The mosfet based R/R can produce a 14.2V but produce 200 watts because it dumps a lot less of it as heat. You would feel this heat sink run a lot cooler after the same duration of running in the same ambient temps as above. As in, more current, slightly less voltage and a hell of a lot less heat.

TBH, its possible to construct a circuit with mosfets or diodes to do this really. I can replace the diodes with better and higher capacity etc etc diodes and get it to do the same thing too.

Cool.
Srinath.

Title: Re: R/R ?
Post by Berzerker on 03/11/20 at 17:56:14

I will check voltage. I've only had a chance for a couple short rides between fixing alot of issues here an there. So I'll keep my eye on alot of excess heat on battery. And think u siritha for the explanation I appreciate it.

Title: Re: R/R ?
Post by Berzerker on 03/11/20 at 18:04:35

And Verslagen, I do read alot :). Every time I fix one thing then put the bike back together something else goes wrong or brakes or I become aware of the issue after the fact. So I'm hoping I'll be able to fix everything this go around and actually ride it, really ride it. So while I have it out I'm gonna fix the broken an striped out head bolts, and replace cam chain tensioner, if u have one for sale. And wanted to make sure there was nothing else I needed to do.

Title: Re: R/R ?
Post by batman on 03/11/20 at 20:12:37

At the risk of being dumped on ,let's look at the advantages of what the battery you want to use at greater expense has to offer, It has more power at startup ,but the stock lead/acid battery has more than enough also ,if the bike is tuned. It also holds it charge and my not be subject to freezing over winter in a cold climate ( not sure), but it has disadvantages as well, If it ever does need recharging it requires a special one at an added cost, unlike a stock battery that could be jump started it can't be without risk, and it dies without notice. If the difference in weight seems to appeal to you .You should be aware that the difference to seemingly "gain" one hP would have to be 12-13 pounds. Some have gone to smaller batteries thinking to shed weight ,not realizing that the battery has two functions one, to start the bike, and the second is it's mass, to absorb power surges ,the same thing you're think about when you consider using a Mosfet RR , again at added cost (about 1/3 more than stock -$150 on line)
I would think about a 14AH sealed lead/acid or AGM battery as a better, and much less expensive choise.

Title: Re: R/R ?
Post by Berzerker on 03/12/20 at 16:02:42

I already have it in the bike, and my other bike and multiple chargers. And it's been fine. They also have jump start tech, so you'll never have a dead. Its been great in my other bike so I put one in this bike, I just wanted to make sure I wasn't gonna break somethen else. But thank u for the info. I'm just waiting for parts then the rebuild begins. :)

Title: Re: R/R ?
Post by ohiomoto on 03/12/20 at 18:05:43

I've had an AG-801 in my bike for 3 years now. All stock electronics. It stays in my bike year round. Sits in the bike all winter. Never put a charger on it, just fire it up and go.

Title: Re: R/R ?
Post by Armen on 03/13/20 at 07:22:15

Hey Berz,
Post some pics of your build!
Gung Ho :-)

Title: Re: R/R ?
Post by Berzerker on 03/13/20 at 15:02:46

I don't know how to upload pic so here's a link.

https://ibb.co/9srw77v

Title: Re: R/R ?
Post by Berzerker on 03/13/20 at 15:05:09

https://ibb.co/hD7qC2k

Title: Re: R/R ?
Post by batman on 03/14/20 at 21:16:37

Berzerker, you already have the battery in your bike and NOW you come at us with questions? kind of bass ackwards don't you think? I guess. Verslagen was right on the mark!

Title: Re: R/R ?
Post by Gary_in_NJ on 03/15/20 at 07:29:32

Berzerker, what brand and model battery did you install? Many of the newer batteries have internal thermal and voltage protection. A FET based R/R is unnecessary for this application.

Also, requiring a FET based R/R s required if the battery chemistry is Li-CO. The battery you purchased is more than likely LiFePO4. This chemistry is used in automobile starting batteries as well as power sport starting batteries because it is thermally stable. The reason LiFePO4 is used in starting batteries is they have a high discharge current, are non-explosive, and have a long cycle life. The disadvantage is that this chemistry has a lower energy density than typical Li-Co cells.

A $150-$200 R/R is not necessary for a LiFePO4 battery.

Title: Re: R/R ?
Post by Berzerker on 03/16/20 at 16:38:19

Thank u Gary, it is a lifePo4 battery. It's a antigravity a10 I believe.
And yes I put it in then asked the question and that is back ass words. I have one in my other bike and it's been great so I put one in this bike, then came across that thread and just wanted to make sure there wasn't something different in this bike that would make puting it in this bike a problem. Like the The head plug failure, if never seen another motor with a hole in the head that a rubber plug is supposed to go in an keep oil. Thank u for all your input it is appreciated.

Title: Re: R/R ?
Post by Gary_in_NJ on 03/16/20 at 19:21:46

Antigravity lists it’s ATX12-AH battery for the LS650. That’s a monster of a battery with 360cca. It also has a full BMS. No special r/r required.

Good battery choice.

Title: Re: R/R ?
Post by Armen on 03/16/20 at 20:03:56

Again, my concern with the stock Savage charging system was the potential to overcharge. 15.5 volts is listed as the acceptable top rate of charge for the stock R/R. This will kill any lithium battery I've ever seen.
So, if you test the bike, and the R/R you have is allowing the system voltage to go this high, swap out the R/R. If you are going to do that, why not use one that is designed for a Lithium battery?

From the Antigravity site:
The Antigravity Battery normal voltage is 13.2V. The battery will read up to 14.7V immediately after charging. The normal operating range will read between 13.3-14.5V. After a few hours it will self-balance to the 13.3-7 range which is its normal state of charge. The maximum voltage the battery should be exposed to is 14.7V. On the lower end of the voltage range the battery should be put on a charger if the battery voltage drops below the 12.5V range while sitting. The voltage should not be allowed to drop below 11V while at rest. Permanent damage may occur below 11 volts.

Title: Re: R/R ?
Post by Gary_in_NJ on 03/17/20 at 05:31:51

Armen, what you are missing is that a BMS battery self regulates. If input voltage exceeds at preset limit, it no longer accepts a charge. Conversely, if voltage drops below a set limit, it also disconnects to stop further drain.

BMS = Self Regulation

Title: Re: R/R ?
Post by srinath on 03/17/20 at 06:13:39

If the battery shuts off the over voltage and the R/R constantly produces too high a voltage, you will in short order burn the R/R.
The R/R has to dissipate it as heat, and unless its dumping less than 20-30% of the output from the alternator as heat it will die in short order.
Then you don't have to worry and buy a mosfet R/R LOL.
Cool.
Srinath.

Title: Re: R/R ?
Post by Gary_in_NJ on 03/17/20 at 06:31:53

https://www.orionbms.com/general/how-it-works/

BMS obviously work, if they didn't we'd be hearing about millions of failures and fires.

Title: Re: R/R ?
Post by Armen on 03/17/20 at 06:39:13

So, when the stock system ramps up to 15.5v, the battery shuts down incoming electrons? Hence, the battery isn't being charged? Maybe a nice feature to protect against momentary voltage spikes, but not so great when the battery won't be charged for long periods of highway cruising.
Unless I'm not understanding.

Title: Re: R/R ?
Post by srinath on 03/17/20 at 06:40:42

The permanent magnet rotor in most old motorcycles like ours will not allow something like it to not destroy the R/R.
If it had a electromagnet rotor (which is also pretty old tech), that would be a good option, it can shut off the charging system at the source.

Cool.
Srinath.