a branch off the "Jota battery" thread

19753C(E)

19753C(E)

Full member
Location
Wisconsin, USA
I was reading with interest what batteries people choose for their Jotas as my triple has an old battery which will likely die soon.  The Odyssey PC680 sounds a popular choice.  Went to the Odyssey web site, http://www.odysseybatteries.com/motorcycles.htm for more information.  My question is how you choose which battery is appropriate?  For instance, Curtis at Harpers recently sent me a PC545 for my LeMans Mk1.  The website suggests a PC925 which is a beast at almost 30 pounds and twice the CCA and Ah of the PC545 but Curtis says the PC545 is plenty.  So why the PC680 for a triple vs, say the PC545?  Are there threshold values of Ah and CCA that need to be met?  Do you just get the most powerful battery you can afford or will fit?
I know I should just buy a PC680 for the triple and shut up but I'm tired of being ignorant (had lots of practice).
 
I never trust 'recommended' battery lists. 12v is 12v you just juggle with capacity.
Small= light, but low capacity, large = heavy but more capacity. Your call. I go for maximum reserve capacity.
Personally, I measure the battery box and fit the largest I can, of whatever battery technology I prefer.
I prefer motobatt over odyssey, not least because of the doubling of connections, front and rear.
 
Hi, I have the PC545 in my Guzzi LeMans III (with Valeo starter) for years now - never failed. But I bought the PC680 for my Laverda 1200 SC with Bosch starter - excellent performance! Ciao, Gert
 
My question is how you choose which battery is appropriate?
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You need enough power to turn the starter motor  when the engine is as cold as you are likely to use it (thick oil = more power required; cold temps = less efficient battery).  I think the stall current for the triple starter is around 200A - a motor in decent condition will pull about half that. 

Then think about retaining enough volts on the battery to reliably fire your ignition module - nowt if you have the original HKZ system pre '79; 11v+ in the case of the later BTZ; less than that for Ignitech & DMC. 

Then add on the effect of ageing - reduced battery performance and factor in something to account for a battery that is less than fully charged.  Not to mention deteriorated wiring!

So after that 'how long is a piece of string' stuff, my experience is that a 14Ah capacity on an AGM battery like the Odyssey is just sufficient to whack over a large capacity high compression triple when cold.  I'd want something a bit bigger than that if talking lead acid because its higher internal resistance means fewer amps flow.  Factory used 24Ah for the RGS and that's more than enough.

Looking at Odyssey spec (and ignoring for the moment their valid comment about pulse cranking amps - PCA), then the PC545 has 150 CCA; PC625= 220 CCA; PC680 = 170 CCA  The latter is close to the original spec lead acid battery which is possibly why it is widely used.  I use a 545 on my spaceframe for space (hah!) reasons - 680 on everything else. 

Wouldn't consider LiFeP04 due to uncertainty about long term performance in less than ideal operating conditions. I've not had good results with MotoBatt - 2 failures where they suddenly just lost/failed to hold charge.  Odyssey work for me - but I do make sure to occasionally fully recharge 'em when there is a standing load present (some reg/rects pull a milliamp or two when bike is parked up: not good over extended period of time). Left disconnected and cool they'll stand a year without attention.
 
I've had a Motobatt  14ah battery on my 1200 Mirage 1979 vintage for approx 5 years. Standard BTZ ,dont ride with lights on. The spec of battery indicates plenty of CCA for starting. Rode to Italy and back couple of years ago without any issues.
I only tend to put a charger (Optimate) on now and again and then for only 24 hours.

To be honest I'm planning to run over to Breganze this summer and may replace it before I go.
Andy
 
I've used Shorai (LiFeP04)  in modern race bikes for years now and they have been faultless even with the long periods of inactivity between tuning/racing. My Aprilia hasn't turned a wheel since October and it is still fully charged and starts first time.

As you'll have noticed on the other thread, I have had some problems recently as a result of a bad earth which prevented charging, and then because of my bad wiring of the laser detector. These were both my issue not the battery.

That's said, if they get over discharge like that then you can't just jump start and off you go! So I'm planning to switch back to a gel battery at some point so I don't have to worry about that.
 
If you (I) keep riding a Laverda triple with an original charging system which is unable to match the load of the lights, does the bike just stop eventually or will the battery just be too low to re-start it later?
 
Ah a cryptic answer I see Grant

Hint my 3C still has the original charging system ..............and I ride all the time ( well most of the time ) with the lights on...

( except the time the bloody Jota was over charging )

Deka batteries for me ..........been there and done that with Motocrap... oops should I say Motobatt
 
Various said:
If you (I) keep riding a Laverda triple with an original charging system which is unable to match the load of the lights, does the bike just stop eventually or will the battery just be too low to re-start it later?
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As I understand it, the original HKZ ignition (pre-79 ish) is self generating so will even run with no battery.  That could be confirmed by people with more experience of them, I've never had a bike with it.  Obviously, that would keep going till you needed to re-start, and even then they bump start quite readily, you'll just have no lights.
The later BTZ bikes, or anything with a more modern ignition will indeed stop once the battery gets low enough.  One time I blew the inline fuse I put between the regulator and the battery on my Corsa, so it was not charging.  Out for a day ride the bike started misfiring at high rpm on the way home, gradually getting worse and coming in at low rpm.  I just managed to limp home having turned off the headlight and only being able to run up to about 3000rpm, but it was still running.  That was with a Mk1 WITT ignition.
 
Steve
Sounds like what happened to me exactly on the Jota on the way home from a club meet first real run on that bike... one night was bloody scary stuff coming through the back of the creek area without lights and a faltering misfiring engine.............grr.... some genius sudo poor excuse for an auto elect.. had struck the connector at the battery terminal had failed. as they had crimped one of those el cheap and nasty crimp connectors them soldered it... so what happened, exactery the bloody thing broke... solder and crimps just dont work

3C has a Witt series 1 but the stock charging system and I run with the lights on... if it has a big day run like trip back from Broadford then yes will need to put the charger on overnght as will be real lazy to wind over the next day without. Its only ever stopped once and that was the main ignition fuse holder blade had failed.... those dodgy fuse boxes from back in the day.. should swap it for a modern one but then would give Mr Rivet something else to pick on  :o so just fixed it.................
 
breganzane said:
As I understand it, the original HKZ ignition (pre-79 ish) is self generating so will even run with no battery.  That could be confirmed by people with more experience of them, I've never had a bike with it.  Obviously, that would keep going till you needed to re-start, and even then they bump start quite readily, you'll just have no lights.
The later BTZ bikes, or anything with a more modern ignition will indeed stop once the battery gets low enough.  One time I blew the inline fuse I put between the regulator and the battery on my Corsa, so it was not charging.  Out for a day ride the bike started misfiring at high rpm on the way home, gradually getting worse and coming in at low rpm.  I just managed to limp home having turned off the headlight and only being able to run up to about 3000rpm, but it was still running.  That was with a Mk1 WITT ignition.
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Although the HKZ should keep going regardless of battery state, there is a relay under the seat which must be operated for the motor to run. When the battery is flat, the relay drops out and the bike stops.

If you take the cover off the relay you can wrap an elastic band around the relay parts to hold the contacts closed. Then all that's required is to bump start the bike, and away you go. Simple, eh?

Cheers,

bazzee
 
Dellortoman said:
I would have bypassed the blown fuse rather than limp home with a failing battery.
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At the time the bike was still running fine down low and I didn't know what had failed (assumed a reg or something similarly unrepairable on the side of the road) so there seemed little point in stopping.  I sussed it was the battery going down when quite close to home and with the headlight still on it would cut out in time with the blinker.
Anyhow... my point was just that in reference to the question asked, it will not suddenly cut out with no warning but gradually run worse and worse as the battery discharges.

From Bazzee's description the HKZ might actually go from perfect to dead when that relay opens.  If it is properly self-generating then it would run fine at any revs or battery voltage, only stopping when the relay opened.
 
I just use a cheap Sears riding mower battery.  They are a little small for the battery "box", but that's okay, I just built a little hut for the Witt computer and strap it in on the side of the battery.  At about $60 US, they're not expensive, and they're lighter than the stock unit. 

 
Rob said:
Wouldn't consider LiFeP04 due to uncertainty about long term performance in less than ideal operating conditions.
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\

Absolutely nout wrong with LiFePo.
 
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