New Battery Recommendation

[jp9094]

Recently (last week or so) began to have starting problems on the '83 LS. Believe it to be a battery issue, but in my haste removed the battery tonight believing my charger was upstairs in the apartment, and before load testing it! Output reads 12.47 volts, but this is meaningless without a load. Assuming I am correct and it needs replacing, what is the consensus on a good replacement. Battery is marked "BMW EXIDE 12V/19Ah/ 170A. Back of Battery says "Recharge Before CW 09-13" and "Charge at supplier CW 41-12".

Thanks in advance!

[BPT]

After a long period of charging problems and going through 2 BMW batteries in a short period of time, I am very happy with the UPG version that I saw here on the forum.

I think there are one or two places listed here that offer a discount to forum members but I found it on Amazon even cheaper (seems like $40-45, shipping included).

It's been great.  I've been an infrequent rider for a while but this thing always holds a good charge, even when it's been sitting and I forget to put it on the trickle charger.

[Bob_Roller]

Do an online search for UB12220 battery .

Usually from 18-22 ah rated .

Make sure it's an AGM / SLA battery .

AGM, absorbed glass mat, SLA sealed lead acid .

Sealed, no servicing possible, spill proof and leak proof, unless you really over charge it .

[BPT]

That's the one I was talking about, Bob Roller.  Sorry, I didn't have the details when I posted.  Here's a link for Amazon.  I can't remember who I bought from but there are 3 here, all for $45, shipping included.  I'd check ebay as well.

https://www.amazon.com/UB12220-Wheelchair-Medical-Mobility-Battery/dp/B007L4JXF6

Also, if you go with one of these, the posts are smaller than the standard BMW battery and have smaller diameter holes.  They come with the hardware but don't lose it like I did.  It fell out of the box and I ignored it, didn't realize until I was away from home and had put the battery in the bike that I couldn't use my old nuts and bolts to connect everything back up.

[Justin B.]

I have one of these in each bike.  Fits R65, R100, and R1150RT.

[Barry]

A rested voltage of 12.47 volts is not necessarily meaningless.  It indicates approx. 75% charge. 12.65 volts would be fully charged.

I'd be inclined to fully charge the battery then have it load tested.  If it still needs replacement the generic AGM batteries already mentioned above are hard to beat for good value.

[Bob_Roller]

As Barry has stated, fully charge the battery then get it tested before purchasing a replacement .

From the code on the battery, I would say it was manufactured the 41st week of 2012, that would make it a bit over 5 years old .

I don't know what kind of situation you have for parking the bike, but if you can get a battery maintainer to keep the battery fully charged during the winter off season, it will help extend the life of the battery .

Forgot to mention the Odyssey PC680 battery, at one time, it was the standard that all motorcycle batteries were compared to .

In the environment I live in, all batteries last about the same 24-30 months, so I have been using the generic AGM type batteries for the last 17 years .

[brennain1]

Just as an aside how do you guys load test a battery. Here in the U.K. we’de generally take the battery to a car spare/accessories shop where they have the equipment to test it.

[BPT]

I've seen sone benchtop type, smaller load testers, but I've always taken them to the auto parts store.  When I was having the problems I mentioned with the BMW battery, my local motorcycle shop tested it on the small, simple one, and said it was fine.  The auto parts store  told me it had a bad cell. So I've decided that for chasing gremlins, the more complex ones are probably best.

Here in the US there is no fee for testing.

[jp9094]

Many thanks for the prompt replies and the sage advice!. Finally located my battery tender and connected it up. Took around 20 minutes to reach 80% charge.

I have been told to load test the battery, connect a voltmeter to it then attempt to start the bike. The voltage should not drop below 9 volts and should be able to maintain 9 volts for at least 30 seconds.

Once it is charged I will replace it in the bake and try the load test!

Again, many thanks to all!

[Tony Smith]

Firstly, and up front - I do not know the specs on the wheelchair battery being recommended so what I have to say below may not apply.

Batteries are designed with their intended use uppermost in the designers minds - some batteries are designed to survive long terms of inactivity without self-discharging, others are designed to be discharged to very low levels repeatedly without dying of it and others are designed to accept varying charge rates.

What I am trying to say is that just because a battery fits the hole in the frame doesn't necessarily mean that it is a good idea to fit it to a motorcycle.

Consider the life of a battery in an R65 - it gets clobbered with a fairly high discharge rate on starting, the cranking current can be very surprising, particularly with the older Bosch starter.

Once the engine fires up the battery then cops 280 watts of charge current (yes I know its less than that depending on what is turned on, but you get the idea).

A battery for a motorcycle needs to be "start rated" in order to survive - like most here I use SLA batteries, they are wonderful things. I once made the mistake of fitting a battery made for use in uninterruptible computer power supplies, it fitted perfectly, although the terminals were a bit small. The brand new battery also died within a month because it was not designed to cope with the high amperage cranking current. I am told that had the cranking current not caused it to fail, then the high charging rate (yes I laughed too) would have killed it in short order anyway as it was designed to be charged at what amounts to a trickle.

I strongly suspect that a battery designed for use in a wheel chair was not designed to cope very well with life as a motorcycle battery, although i am prepared to be wrong I would suggest sticking to batteries whose manufacturers intended them for use as start batteries.

[Bob_Roller]

Here's the spec sheet for the batteries that I have been using for about 12 years .

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

At the bottom of the page, are the recommended uses for this battery, motorcycles, lawn equipment, snowmobiles and powered water craft .

I can't speak for any ones particular situation, but the Odyssey PC680 battery gets the same service life as one of these generic batteries (24-30 months), in the incessant desert heat that my motorcycles are subjected to, at one third to one half the price of the PC680 .

[jp9094]

Finally got the charge up to almost 13 volts. Re installed it and the bike started with a single touch of the started button ( and no choke). Was not quick enough to note the voltage drop, so will haul my battery tender down to the garage and have it on stand by. Will hope for the best.

Thanks to everyone!

[Barry]

I strongly suspect that a battery designed for use in a wheel chair was not designed to cope very well with life as a motorcycle battery, although i am prepared to be wrong I would suggest sticking to batteries whose manufacturers intended them for use as start batteries.

I can't fault the logic of your point but like Bob I'm running a cheap "AGM type"  battery that cost £32 which was half the price of a motorcycle specific AGM and 1/3 the price of a PC680.  It's coming up to 4 years shortly and still seems to perform like new. I have every expectation of it lasting 5 years or more.   On this experience motorcycle specific batteries struggle to make economic sense particularly the PC680. 

Buying a PC680 would break my simple rule:  I have no intention of paying the same price or more for an 18 AH motorcycle battery as I do for a good quality 85 Ah Varta battery in my car.

[Bob_Roller]

jp9094, to get a better look at the battery condition, turn the fuel tap off, run the carbs dry until the engine won't run .

Fully charge the battery, then operate the starter, you need to operate the starter for about 30 seconds to get the top charge off of the battery .

Then keep operating the starter and see what voltage you get .

Also, the type of riding you do has a great  effect on the charging of the battery .

Slow speeds, traffic lights, ect, the charging system on these bikes barely supplies enough power for the electrical use of the bike, let alone charge the battery .