Dead Battery

[Crossrodes]

My '79 R65 wouldn't start this morning.  So I checked the battery.   It was dead.  It is a sealed Odyssey battery which I think is a pretty good battery.  It is 6 years old so it is probably at end of life (currently I am recharging it and will test it to see how long it will hold the charge).  But I'm guessing it is toast.

I dug through my records and found I paid $168 (Canadian) for this battery.  It has been a pretty good battery but it was very expensive.

So what make/model of battery is recommended these days for the R65?

Mike

[Bob_Roller]

I don't know if these companies ship to Canada or not .

http://www.gruberpower.com/12-volt-18-amp-hour-ah-battery

http://www.staabbattery.com/product/UB12220-V.html

Currently out of stock at radio Shack .

http://www.radioshack.com/product/index.jsp?productId=11909407

All of these are AGM type batteries .

[Barry]

Given the high price I would be unhappy at an Odyssey lasting only 6 years in a moderate climate. there is always a risk of premature failure and for that reason I would not buy a battery in that price range.

I recently bought a new battery and the way I saw it there were 2 options:

Buy a quality wet cell at 60-70% of the cost of an Odyssey. In a moderate climate it will last 10 years with ease if properly maintained and charged but the looking after does get tedious especially towards the end of it's life. I don't think it's an exaggeration to say 9 out 10 owner don't maintain wet cells properly and so don't get the service life they are capable of.

Buy a cheap generic AGM of the type Bob mentions which will owe you nothing if it lasts only 3 years. Compared to even a new wet cell the ability of an AGM to hold it's charge will be a revelation and if the bike is used regularly maintenance will be zero.

I chose a cheap generic Ultramax SLAUMXNPG20-12 AGM/Gel battery available in the UK and have been very pleased so far. I particular like the top mounting terminals which are so easy to access. Only negative point is the terminals are not shielded against inadvertent short circuit.
http://www.ebay.co.uk/itm/12V-20AH-Replace-17AH-18AH-19AH-21AH-22AH-ULTRA-MAX-NPG20-12-GEL-Battery-/131100536915?pt=UK_Health_Beauty_Mobility_Disability_Medical_ET&hash=item1e86337053

[Crossrodes]

Thank you both for the info.  

Barry, it has been my experience that a battery will usually last about 5 years.  I do live in a mild climate and I do look after the batteries. If I don't use the bike for a couple of weeks I put the battery on a charger.

Right now I have been charging the battery for about 30 hours (2 amp charger).  Originally it was sitting at about 3 volts.  It is now up to 12 volts and still charging.  Once I get it fully charged I will let it sit and see if it holds the charge.  I am also wondering if I have a short in a circuit on the bike that could have caused it to discharge to that low a voltage.  So I'll have to check out the circuits too.  The other possibility is that the alternator is not working but I don't know how the battery would get as low as 3 volts and the bike not quit if the alternator failed.  I'll check it out too.

[Bob_Roller]

At six years in service, the most likely cause, is an internal failure of the battery .

My last Odyssey battery only lasted 28 months, that's when I went to the generic AGM batteries .

[Barry]

I don't know how the battery would get as low as 3 volts and the bike not quit if the alternator failed.I'll check it out too.  

A wet cell is considered fully discharged at 10.8 volts. For an AGM like the Odyssey it will be a little higher in the low to mid 11's. There is no way it could have run the bike like that and it couldn't have got down to 3 volts purely from normal internal self discharge so it must either have developed a fault or as you say maybe a permanent current draw.

[Crossrodes]

Update....Well I charged the battery to 12.4 volts.  I thought it would charge up to 12.8 but no.  Anyway the battery seems to be holding the charge as I let it sit out of the bike for about 12 hours and it is still at 12.4.  

So I started checking out the circuits on the bike.  When I checked between the large positive cable which runs from the battery and ground it measured approximately 1.5 Ohms.  So I'm guessing that I have a component failure there somewhere.  So now I'm going to see if I can find the cause.

[Barry]

So I started checking out the circuits on the bike.When I checked between the large positive cable which runs from the battery and ground it measured approximately 1.5 Ohms.So I'm guessing that I have a component failure there somewhere.So now I'm going to see if I can find the cause.  

That's some current draw. It would have the battery flat in no time. Diode board could be a suspect.

[Crossrodes]

Barry that's what I'm thinking.  I'm in the process of opening up the bike so that I can check things out.

[Crossrodes]

Well I have finally done some more work on the bike.  I removed the top engine cover and the cover for the air cleaner.  And now my short has disappeared.  I have checked out the cable from the battery (it goes to the starter motor) and see no wear that could cause a short.  There is also a wire that goes from this cable to the diode board.  Is it possible that I have a short on the board that disappeared because I was shaking things when I was removing the covers?

[Barry]

Is it possible that I have a short on the board that disappeared because I was shaking things when I was removing the covers?  

Doesn't seem likely if it was a component failure on the diode board. Once diodes fail they don't repair themselves.  If it's something to do with the diode board mounting then maybe.