Testing Your Motorcycle Battery In The Field

[@tammy1001]

Thanks for all this detail, a great help for a beginner.

[@tinks43]

Great to see on 3 examples 👍🏻

[@onanysundrymule3144]

This is a really good and informative video, thank you Sir.

[@umik8512]

Great video, helpful 👍

[@DTA555.]

I checked mine everything is a lot better but I have a newer battery. It’s 4 degrees right now so I wanted to check it to make sure it wasn’t draining in 4 days.

[@paullandry5907]

Great info! Thanks!

[@BloodBath1234]

Speaking of batteries, what are your thoughts on Lithium Ion batteries? Great videos.

[@tinderboxarts]

The AGM batteries do a great job in all temperatures and they will last a long time if you treat them well. I routinely get 5-8 years from one. So what does lithium technology buy you? They are not as reliable in cold temperatures, requiring special attention. They are more expensive. They will require a new or newer charger able to cope with the lithium voltages. Their claim to fame is really that they don't self-discharge when left for a couple months and that they are lighter weight. The self-discharge thing isn't an issue for me, I have a garage with maintainers. The weight savings is also not of big importance to me. I'm not running track days, I just ride on the street and I don't weigh much myself. So, for me, the AGM batteries get the job done for less money.

[@aureliomartineztamez9639]

Gracias desde mexico

[@roadwarrior8560]

Thanks, subbed

[@DiZlat]

THNX for the videos!! What if the charging voltage comes up to 16.5 or even 17v?

[@tinderboxarts]

That's way too high, and you will cook your battery. A high charging voltage means the voltage regulator is not doing it's job.

[@DTA555.]

@@tinderboxartsI was just going to answer his question and the voltage meter needs to be changed but check everything also. There is a lot that needs to be looked at and make sure that you don’t have your trickle charger hooked up when doing this.

[@iamwezlee1]

Great video! Very easy to follow. Since we’re talking electrics, do you have any way of testing the stick coils on your RT? My bike began intermittently running rough. I THINK it’s my right side secondary coil but I’m told there’s no way to test the coil. In your experience is this true?

[@tinderboxarts]

These coils are not magic, they are just like hundreds of other ignition coils for cars and bikes. They have a primary and secondary winding, each of which has an associated resistance value for a good coil. You can put an ohmmeter on each winding and compare the reading with the spec, which is the start of a good diagnosis. The trouble is, I don't think BMW publishes the spec! You can comb forums for ideas on what your model year resistance should be, but it may be inaccurate. What you CAN do is take readings on all of your coils and compare them to each other. If one is particularly different from the others, that's a red flag. Even without a meter you can swap coils to see if a problem follows the coil. Of course, there are other issues that may make a coil appear bad, such as corrosion at a connector or a broken wire in the wire loom. Temperature can make a difference in performance too. So, you have to be methodical in your approach. I would start with an ohmmeter and compare readings among the coils and you can also jiggle the wire loom while the engine is running to see if anything happens. There are lots of other reasons for a rough running engine, too. The ignition system is high on the list, though.

[@percusski]

Great video

[@Knotfest09]

My new battery reads 12.3 to 12.4v when the ignition key is on is it low or good?

[@tinderboxarts]

Are you using an actual multimeter across the battery terminals to get your reading, or are you relying on a dash readout or charger display for those numbers? Only a meter across the terminals will give you an accurate reading. For a fully charged AGM battery you should see 12.8 or 12.9 volts. But, a slightly lower reading in the 12.6 area is common and not a sign of a problem. You'll also notice that the numbers initially drop slightly when the key is turned on and the headlight causes a drain. If you are getting 12.3 with a meter and the battery at rest, then that is slightly undercharged. It could be your charging system isn't keeping up, or the bike has been sitting awhile, or the battery is getting older. You'd have to investigate further.

[@Knotfest09]

​@tinderboxarts I'm only relying on dash readouts when turning the key on my volt shows 11.9 and then goes up to 12.3 to 12.4v and then when the engine is open 14.1 to 14.2v. I already ordered a multimeter, I'm just waiting for it to arrive.

[@Knotfest09]

​@@tinderboxartsAnd is it possible for the voltage to drop even more when you turn on other accessories like the hazard lights even though the engine is on? because I noticed when I stopped for a while and turned on the hazard lights the voltage dropped to 13.5v and when I turned it off it went back to 14+v sorry if I have a lot of questions I'm still a beginner in these things and also thanks for the info and videos you earn a new sub ❤

[@tinderboxarts]

This is a huge subject, but you should understand that WHERE you read the voltage is important. A voltage drop occurs when there is resistance. Suppose your battery has an actual voltage of 12.6. Then suppose you connect a wire to each of the battery terminals, but one of those wires you don't connect very tightly or you leave some dirt between the wire and the terminal. Now you measure the voltage at the end of those wires. Instead of getting a 12.6 reading, you'll get something less, perhaps 12. That's because there is a resistance in the wire which is poorly connected or has some dirt in the connection. That's why it's important to measure right at the battery terminals with a real meter. Your dash display is even farther removed from the actual battery, and it's displaying a reading which is taken from the bike computer through a whole wiring harness. Plus, it's using a crude measure of voltage not a meter dedicated to the measurement. It basically useless. So get your real meter, do the tests in the video, and you'll know where you really stand.