If you have similar batteries with different capacities the biggest battery will always have most crank-power, if both are charged 100%.

The problems with big batteries are:
-Weight
-Price
-They stress your charging system
-They usually need more time to get fully charged

On the other hand driving in cold weather (-10°c and below) or with a highly modified engine you might (or will) reach the limit where a standard 19Ah battery can’t deliver the crank-power you need. It also depends on a lot of other factors like your charging system, oil, compression, how easy the bike starts, type of starter etc.
If you are on the low side with cranking-power you will use a lot of your battery’s capacity to start and it will require a long time recharging

A battery has full capacity at 25°c, at -18°c it’s only 40% left. This means that my 19Ah battery only have 12Ah left. That’s not much when it’s cold…
As a rule of thumb you should have 14.2-14.4V at 25°c and increase the voltage with 0.3V for each 10°c the temperature drops. (-15°c => 15.1-15.3V)

There are a lot of things that can be modified on the airheads-charging systems to get better charging.
My charging system is original (except a Thunderchild diode-board). I haven’t rebuilt it because for my use it works. It’s always easy to start the bike if it’s hotter then -10°c (or -15°c with synthetic oil) and that’s enough for me. The numbers might be a bit better now after I fitted the ND starter.
If you increase the voltage (which is good for your battery) you will also increase load on your generator. But again; different needs requires different solutions.



Hmm, eight years ago I had approximate 8 km (7-15 minutes) to work. In January/February I had to drive some extra kms 1-2 times a week to keep the battery up. The rest of the year it worked flawless.
I guess it works as a rule of thumb on a healthy system operating in normal temperatures.

I replaced my yuasa battery with an odyssey in my XT600E..

The difference is the cranking power and HOW LONG it will crank...

If you're having any types of problem and your bike isn't catching on the first 1-2 cranks, then having a battery which won't flatten in a few minutes is definitely an advantage..

The odyssey has a really deep cycle meaning if can sustain those high amps for a greater period of time..

I have to agree with Alibaba though, running parallel only works if BOTH batteries are in very good condition and using a high amp battery does take longer to charge.

__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

Hello Alibaba,

I ride my bike mostly over 0 C (celcius). It's upgraded to 1000 cc bike. Do you think Odyssey 680 will be much for that or should I go for something like normal 19 AH battery like BMW you mentioned.

I know BMW doesn't make any accesories itself but makes it to produce other companies. May be we can find it cheaper under another brand !

I am a bit confused now...

Regards,

Sami

__________________
"where the traveller goes, nobody knows ! "

I don’t know the Odyssey 680 first hand. It’s 17 Ah compared to the standard 19Ah.
Personally I had chosen the standard-battery if the price is more or less the same.
A lot of US-riders are pleased with Odyssey.


The battery is made by Exide technologies, but I can’t find it in their catalogue.

As stated.
I have tested BMW, Banner, Yuasa, and a few more. None does even come close to the power and reliablity of the Odyssey.

The pricetag is just about x2 for PC680 vs standard 24-28Ah; but it is well worth it as I see it.
Remeber, I am used to Banner 30Ah and find those to be far better than any 28-24-19Ah batteries - and the Banner 53030 is out-classed compleatly by the Odyssey...
Remember that the beemer have a tendency to discharge it self... I know for a fact that there are some major problems getting the electricity to stay put in an acid battery on the beemers... and to get them charged by the stock alternator... The Odyssey surpassed my wildest expectations by far - it works where the acid batteries does not.

However, all batteries with the modern technology are said by my friends and aquaintancies to be superior to acid batteries.
SMF techonogy:
Biltema Sverige
Gel technology:
Biltema Sverige

Still a new battery is better than an old worn -

__________________
Drive Safely,
Albert

I agree with the Odyssey fans above. I've had an Odyssey in my R65 for a few years now and have never, ever had a problem with it, despite leaving it connected for months without starting it still started the engine first go. It can be charged and stored for months on end, it can be deep discharged regularly (they are used for racing engines with no alternators). It can't freeze, even at -40 C, it is sealed and non-spillable, small but powerful.
I'll never buy a different battery...
Sean