Dead K1200s

A quick google yields this:

"AGM (Absorption Glass Mat) sealed battery technology was originally
developed in 1985 for military aircraft where power, weight, safety, and
reliability were paramount considerations."

 

http://www.tayna.co.uk/YTX14-BS-Westco-Motorcycle-Battery-P3384.html

AGM (glass matt) for 55 quid. Tayna & Westco both recommended.

 

Get with the times, dude. They've been around for yonks.

 

I have one of those and I'm also less than impressed with it. My
housemate's cheapie C-Tek charger, that he got free with a magazine
subscription, has recovered three previously dead batteries that my
Optimate 3SP wouldn't touch. I'm buying a C-Tek and changing the plugs
for Optimate ones.
[/QUOTE]

Hmm, I have an optimate 3 and the only issue I have with it is that
after a few weeks I need to top up the battery it's connected to - I
don't know whether this is normal or whether the optimate is charging
too much.

I also have a "subscription freebie" C-Tek, that's still in the pack.
Can't decide whether to use it or ebay it.

 

Military aircraft, eh? Hav eyou ever seen a Tornado on an Optimate or
being jump-started? No. So that's surely the way to go.

I see Krusty has provided a handly link to cheaper ones.

 

That's as maybe, but I'd never heard of it. Daddy-o.

 

Cool. I think it is a couple of mm wider and taller than the original,
some reports of a snug fit, others having to make some minor adjustments
though not specified what bike.

Have MOT booked for 8.40am tomorrow so really need one today.

Oh and if anyone knows, the battery offered is a 12ah whereas I know you
can upgrade to a more expensive 14ah but what are the factors
determining which to choose?

 

That's TTL logic isn't it? I'm sure the world's move on somewhat from 5V
stuff. Anyways, there's almost certainly some analogue cleverness on the
front end of an Optimate.

 

These people - http://www.tayna.co.uk - were recommended to me
yesterday and I bought an absorbed glass mat (whatever that means!)
battery for the FJ from them.

I can't see the K1200S in their fitment guide but they may be worth a
call.

Kevin

 

As Krusty says, get the AGM but not from BMW. The AGM has better
cranking in colder weather as the chemistry works more efficiently in
the cold. Same basic lead acid reaction but the glass mat environment
provides a better medium. AGM battery will hold a charge for longer if
left unattended, although will still go flat as most bikes have some
sort of current draw e.g the LCD clock on my bike.

As for the 14amp/hr battery: this will help if you make infrequent or lots
of short journeys as the overall capacity of the battery will be greater.
On my bike, BMW fit a 14Ah battery to non-ABS bikes & a 19Ah to ones with
ABS as it takes quite a bit of current to energise the system.

 

Nice explanantion, thanks.

Crikey. Mine has ABS but 19ah is a big old jump from 12.

Trouble is it's MOT day tomorrow and expiry on sunday (great forward
planning) so may just have to take what's on offer locally.

 

it takes a lot of juice to persuade the huge pistons in a boxer twin to
move, especially on a cold day if you have 20W/50 oil as currently
recommended by BMW[1]. I went back to 10W/40 over winter.

[1] for the twins, no idea what they recommend for Ks & Fs

 

I wouldn't worry too much about MOTs. It's only a fine (no points), & I
go several months every year without one & never been stopped yet.

 

annoyingly, my car is 3 years old on the 27th May and as the car was
originally taxed for 53 weeks I have to get an MOT before I can get a tax
disc. I usually let it slip a week or two for most vehicles. My bike has
gone from April to mid June since I've owned it.

 

Heh but I don't do "illegal" (in anything that could possibly be
complicated or have implications on validity of insurance for example).

 

Although I did run my car for a month without an MOT inadvertently, only
realised when I came to trade it and they guy said "and when does the
MOT expire sir?".

 

What makes you think they'd use TTL as a voltage comparator?

A voltage comparator ( an OP-AMP with a smidge of positive feedback if you
like) is far more likely.

Microcontroller chips are becoming increasingly common in electronic battery
chargers, most have integrated peripherals - usually including 1 or 2
voltage comparators for just this sort of thing.

 

Dead last night, barely alive this morning. Had it on the BMW
"optimate" overnight and this morning it didn't have enough to turn the
engine more than once.

************

If its due to sulphation, it should be reversible after only 10 days left
flat, excercising the battery would give you a pretty good sense of whether
its fucked or not.

Root around the garage for any old headlamp bulbs with only one filament
good, you need at least 4, make up a dummy load with the bulbs so you can
discharge as well as charge the battery, a quick calculation of the combined
wattage and the Ah capacity of the battery will tell you how far short its
falling - and whether exercising it is improving it.

Also hook up a multimeter and keep an eye on it - try not to discharge below
10.8V between recharges.

 

wessie used his keyboard to write :
I have not checked my intelligent chargers, but certainly the voltage
required across them before they will start to charge has to be much
higher than the 2v -3.8v you quote above. I would guess at above 10v.

Now why would they restrict themselves to TTL or CMOS logic levels,
when all that is needed is a simple op-amp and a voltage diver network/
comparator?

 

With *some* care. I doubt they're supposed to be left unattended for months
and months on end though.

And it's been sat in Leeds for **** knows how long waiting for someone to
give it a hug.

It's sulked itself to death.