Dead battery? Please see recorded multimeter voltages.

[minieggroll]

Hello,

My GZ250 will attempt to start but will not unless I either jump start it or push start it. I took some voltage readings for your reference to help see what the issue may be.

With the bike off: 12.5v
With the bike on: 12v
When I push the ignition: Drops down to 6-8v and stays around there while the ignition is held

I've read online that the battery is dead if it drops below 9.5v when the ignition is pressed. Is this correct? I checked the voltage while jumping the bike and it never dropped below 10.5v while I hit the ignition and successfully started the bike.

Thanks in advance for your help!!!!

[5th_bike]

Originally Posted by minieggroll

Hello,

My GZ250 will attempt to start but will not unless I either jump start it or push start it. I took some voltage readings for your reference to help see what the issue may be.

With the bike off: 12.5v
With the bike on: 12v
When I push the ignition: Drops down to 6-8v and stays around there while the ignition is held

I've read online that the battery is dead if it drops below 9.5v when the ignition is pressed. Is this correct? I checked the voltage while jumping the bike and it never dropped below 10.5v while I hit the ignition and successfully started the bike.

Thanks in advance for your help!!!!

Good data.
If you measured at the battery poles => it's time for a new battery.
If you measured elsewhere in the circuit, there is a simmer of hope which is that a battery contact could be bad due to corrosion in between battery pole and clamp. I have seen that happen in cars that didn't want to start.
If the battery contact is good => it's time for a new battery.
If you get a new battery, read up on how to properly charge it elsewhere - just search the forum for "New battery".

PS I don't know about the correctness of the 9.5V rule, probably someone else will chime in to yay or nay that.

PS2 You didn't say how old your battery is but if it is over three years old and the bike had periods of no use, it's probably bad.

[Water Warrior 2]

The jump start voltage was likely from the other battery.

[mrlmd1]

Put the battery on a charger with between a 1.5 and no more than a 2 amp output for 6-8 hrs. and measure it again and try to start the bike.
Reviving it may be possible depending on how long it has been at that low voltage.
Remember if you jump it from a car, do not have the car engine running, just use the battery.
And also remember, the battery will not recharge at idle speed - to get enough juice out of the charging system you need at least 2500-3000 rpm so if you start it, take it for a half hour ride.
If the battery takes a full charge and is still good, it should read 12.6-12.8V measured at least a half hour after coming off the charger, and be the same the next morning.

[minieggroll]

The battery is likely very old lol. I bought this bike used a couple months ago (2007 w/ 5800 miles). I have no idea if the previous owner ever changed the battery before. I just bought a new battery from Advanced Auto parts for 33 bucks and put it in this morning.

Yeah, I know the jumpstart voltage is from the other battery, I just wanted to give some results on what effect jump starting has on the cranking voltage.

Here's the youtube vid describing the cranking voltage that shouldn't drop below 9.5v for anyone that is curious:


PS: Didn't realize the acid on the new battery would be separate lol. I was kinda surprised. Also, it says to trickle charge the new battery for a couple hours... yeah, I don't have a trickle charger... should be okay though right?

[mrlmd1]

NO!!
If you bought an AGM battery IT MUST BE FULLY CHARGED PRIOR TO FIRST USE or it will NEVER hold a full charge. You will be back at the store getting a replacement after only a few starts of the bike. You must put that new battery on a charger to bring it up to full charge or it will prematurely die. Be forewarned. The instructions are included for a reason and this applies to all AGM batteries.

Go get yourself a 1.5-2 amp trickle charger and permanently attach the accessory battery plug that usually comes with it for later use. It hangs down somewhere underneath the body panels so all you have to do is hook up the charger when you need it and don't have to remove body panels to get to the battery again.You will need it eventually.

[minieggroll]

Cool, Thanks for the advice mrlmd1. I will go purchase a trickle charger (Does it have to be a trickle charger or can it be a battery tender?)

Also, I have been reading up on AGM batteries. I don't believe mine is one... AGM batteries are sealed. I had to pour the acid into the battery when I bought it...

[JWR]

The directions were very clear on adding the acid, wait a while. add water then charge.

I believe over night on the first charge is the best.

Batteries are considered a wear item.

A 1 1/2 or 2 amp charger is the best.

[mrlmd1]

Yours most likely is an AGM, and on many of them, you, the user. have to add the acid then the battery is "sealed" with the strip that goes over the cell openings. They are not shipped filled with acid. Motorcycles generally use AGM's because they do not spill out acid if you tip them over, like if the bike goes down. The acid is absorbed into a mat, is not a free moving liquid like in larger auto sized lead acid batteries.
A Battery Tender (brand name) or battery "maintainer" is OK, generics are OK, like I said, you are looking for a charging output of 1.5-2 amps, no more or you may damage that little battery. Anything with that small an output is basically a trickle charger, some are a little more fancy than others. Some have an automatic tapering charge, others do not. Usually there is a yellow light to indicate it is charging, and a green light to indicate when the battery has reached full charge.. When the green light goes on, unplug it, wait 1/2-1 hour, measure the battery voltage and if it's 12.8 or so, it's fully charged and all set to go. It may take only a few hours, or it may be much more than that.
If you are not going to use the bike for an extended period of time, as in winter storage, or even if you are not going to ride it for a few weeks, you can hook up the charger/tender/maintainer to bring it up to full charge and that will greatly extend the life of the battery. If you let it get discharged to 12.2-12,3 V which represents a 50% discharge, you will shorten the battery life considerably and may not be able to salvage it depending on how long it has been at that state. During the winter storage, hook up the charger maybe once every week or two to keep it topped up.
If you take care of that new battery, it will last for many years, if not, it will crap out sooner than you would like.
And be reminded, after you start the engine, prolonged idling will NOT charge the battery - you have to get the engine rpms up to at least 2500-3000 rpms to do that, so take it out for a ride, don't let it sit running in the driveway.

[Water Warrior 2]

I have used my Battery Tender to charge a new battery with good results. I just let it charge overnight or longer. Have the 3rd battery in the Vstrom now. First one died over the winter because I didn't have a tender. 2nd one died over the winter because I didn't use my new tender(smart move). Now the bikes get their monthly feeding over the winter and the batteries are fine.