Has anyone else had issues with batteries in their Slim S's? The first battery went out the first week I had the bike, the second battery went out two months later and now the third battery had died. Bike is kept inside a heated and cooled environment. It sat for maybe month and put the battery tender on it last week for a couple days, showed fully charged and went to go for a ride last week and the battery was dead...?

 

When I purchased mine dealer told me to have it plugged into battery tender when parked in garage because of draw from security system.It's a 2016 with low miles & no issues.

 

The security shouldn't kill a battery, my 15 Road Glide has sat for over a month not on a tender and fired right up Wednesday for a ride. The past 3 or 4 bikes have had security and none of them has gone through batteries like the Slim has....I typically keep a bike for 3-4 years and until the slim have never had to replace a battery, guess the slim is making up for the others.

 

You have a draw on the battery somewhere. Poor ground, nick wire, etc. Going to have to find it or the batteries are going to keep dying. But I am sure you have thought of that, good luck on finding it.

 

BadX, you had the ecm update download done ?

 

I have a 16 Slim with no security system that the first one died before I had 50 miles on it. Next one lasted about two years but I had to jump/charge it if it sat for a week. Four other bikes with no issue. 09 Street Bob still has the original battery and can sit for weeks and still start.
I think there's a problem with these bikes and the charging system. Something sure pulls the battery down.

 

A few diagnostics are in order.

1) How long is bike sitting between rides. There may be some slow draw on battery from security system or other source that may affect it if it sits for long periods. In this case a battery tender may help.

2) If the above is not true then you may have a charging issue. If the bike does not die while riding then the problem would seem to lie with a drain on the battery while sitting idle.

 

As yobtaf103 has suggested, there was a stock calibration and super tuner update earlier this year. The purpose was for easier starting by opening the ACRs at ignition on for 10 seconds, rather than waiting for the start button to be pressed which gave the appearance of being a bad battery in many cases.The update included your model.

The update may not neccessarily solve your issue but may help and worth looking into.

What type of battery tender are you using and why are you not leaving it hooked up?
It might be worth considering getting a proper battery charger if you aren't leaving the tender on the bike whilst parked so that you can ensure you have the battery as fully charged as it can be before going to start it. This will atleast give the battery a decent chance of providing a decent starting amperage.
It would also let you go and have it load tested to confirm its state of health. If it comes back as good then you can start looking at your method of maintaining the battery and as also as suggested, you might have an excessive draw on the battery.

A milliamp draw test would confirm that if you are able to carry that test out with a meter.

 

I agree on the possible charging issue. When the battery is fully charged you can check the charge voltage at the battery with a volt/ohm meter. At around 2000+rpm, it should read 13.5-14.0 volts.

 

G'day from Oz. Realise you're question was in regards to the Slim S BUT I have the 103 which is 2 years old now [Stage 1 only, Screaming Eagle Pro Tuner, SE air filter, S&S tapered turbo mufflers]. Have put the HD battery tender on it once a week for 24hrs without fail and the battery appears to be going strong. Mine has the security system, Is NOT ridden anywhere near as often as I'd like [ only clocked up about 1200km last year ], Sits in the shed. Realise our winters are probably no where near as cold as yours but our summers definitely can be extreme with many days in the high 30's to low 40 C's. So far no problems knock on wood.