bike wont start, could battery have a bad cell even if it wont turn over but still has headlights. think I may have got tender on to late this year.

 

Lights will work with a low battery or bad cell. Tender won't bring it up to charge if it is low. Try putting it on a charger. If that doesn't work, take in in (any auto parts store) and have them check it.

 

I did put charger on an when I did the charger showed 25 percent on gauge but climbed to 100 percent very fast but soon as turn on ignition and lights come on the meter on charger drops back to 25 percent in nothing flat and bike don't even make a attempt to turn over,

 

Do this.; As recommended, any of these stores, Auto Zone, Advanced, etc., can do a load test and tell you in no time if the battery is dead.

 

As recommended, have the battery tested. It is definitely discharged. Whether it is bad or not is another matter. Just as an empty Gas Tank does not mean the Gas Tank is bad, a discharged battery does not mean that it is bad. Have it tested and then you'll know. BTW, looking at your Battery Charger/Tender and/or a Voltmeter is NOT a test of the battery.

 

Where did you get the idea tender won't charge a low battery?

 

What's the age of the battery?

This weekend I installed a new battery - the four year old battery would indicate full charge, but the internal resistance had got to high to crank the engine, .....it could power the lights etc.

With the battery being >3 years old, I wasn't going to bother getting it load tested at my local parts store, just paid $90 for a DieHard which is made by East-Penn in the USA.

 

Good question - my tender has an output capability of around 3A, and can most certainly get the battery to full charge.

The smaller battery tenders with lower current capacity will also take it to full charge, but just take longer.

 

I've heard that if a battery is very depleted a tender might not be able to start charging it. I've not experienced that myself, but it's been discussed before on this forum. Not sure what the specific condition that triggers this is, but apparently it can happen. Seems that putting the battery on a standard charger for a while then switching to a tender is the fix when that happens

 

Battery tenders typically output very little and are used for storage purposes. In other words, just enough to maintain a battery. A motorcycle battery charger outputs more and can charge a battery that has been discharged. Most people don't know the difference.

Get the battery charged up then take it to get load tested. While you are at it, check the condition of your battery cables.

If the battery test bad with a load tester, get a an AGM battery. If you have money to spend, you can opt for a lithium ion battery by Anti Gravity.

Also, upgrade your battery cables. Sumax is very good.

I am running Sumax cables and a 720 cranking amp Anti Gravity battery. Very expensive but so far I like it.