Flat Battery

[embee 7,288]

ste7ios is absolutely right here.

 

First, lead acid batteries should always be kept more or less fully charged to avoid the sulphation as he describes. This is clearly explained in various technical sources like the Yuasa site for example.

 

They do self discharge when standing unused and not even connected to anything, but this is getting less than it used to be I think. The very rough rule of thumb used to be 1% per day, but I believe modern batteries are somewhat better than this. Even so, returning to fully charged at least once a month is a very good idea, I tend to do mine roughly every two weeks during winter while they are laid up and not in use.

 

As ste7ios says, not all chargers are equal. If in doubt don't leave it connected longer than necessary, if you're confident it is a suitable maintenance charger then it should look after itself essentially permanently.

 

If you have problems with a battery, first check the simple things. Are the terminals clean and tight? Do you have anything fitted which could add a drain while the bike is not running, like alarms or heated grips which could be left on?

 

It is very simple to do a quick check of the charging with a multimeter directly on the battery terminals. There is a very useful flow diagram here

http://www.electrosport.com/technical-resources/library/diagnosis/pdf/fault-finding-diagram.pdf

but to cut to the chase if you're seeing something like 14.5V when the engine is revved up a bit, it is probably OK.

If you still get problems with it going flat when left, you need to check the current drain with everything switched off and engine stopped, do this by taking the neg cable off the battery and connecting a multimeter between the battery neg terminal and the disconnected neg cable so any current flows through the meter. Set to DC Amps, start at a high range so you don't risk the meter, switch down to a low range and the drain (or quiescent current) should be down in the low single figures milli-amps, 1 or 2 typically.

 

The NC does have a MOSFET type reg/rec as far as I know, and these are generally much more reliable and stable than the earlier type.

 

Ultimately batteries have a finite life, but it isn't unreasonable to expect 3 or 4 years typical use, I've had batteries do 7 yrs. On the other hand I've bought a battery which wouldn't hold any charge from new and was replaced by the dealer no problem.

[ste7ios 469]

No battery is maintenance free as stated... We may not fill them with distilled water anymore but they need some maintenance. 

 

So if you want to ensure battery's longevity and keep unpleasant situations away you must know some basic things... (the #1 is keep it always full!)

 

Yuasa's Technical Manual explain some things:

 

Technical Manual - Yuasa Batteries

 

Also a permanent voltmeter on our dashboard is very helpful because if you end up with a bad regulator or generator you'll know it in time, so you'll save your battery and probably some electronics of the bike.

 

The self discharge of AGM battery is much more lower than convetiional Pb batteries but usually there is a small parasitic draw from bike's  electronics, alarms etc...

 

One more reason for failures is battery freshness. If the battery at the dealer was stored for a long time on a shelf and it wasn't properly maintained, the battery is going to have less capacity... It's good idea to check the date code with the battery's manufacturer. 

[Dave D 567]

Now that I've retired the bike isn't getting used regularly so I have the battery connected to one of the below intelligent chargers so that it's ready to be used at any time.

 

http://www.ctek.com/gb/en/chargers/MXS%203.8

[Guest Tricky]

Hi dos any one know what draw you get on the battery? on cars its normaly about 0.003 amps but my nc700x is highter. ive not checked it for any lenth of time as i do know that you can get a highter reading 1st thing before things wind down. ive had problems with the battery going flat in a week but after charging the Honda garage checked it and said it was fine. The bike is only 2 years old and i have put it on an optimate 3 to charge it but i dont leave it on all the time.

[ste7ios 469]

Max 1.2 mA. (w/o any connected accessories)

[michael 324]

I'm enjoying this interchange.

 

Can't help but think there are a lot of good solutions but one stands out as the best.

 

Ride it!

 

(dreading the onset of shorter days, longer nights, rain and cold asphalt and maybe snow)

[Guest Tricky]

Thanks, checked the draw and its ok . the batterys ok too so ive left it off the bike and checked it every day and its 12.45v so ill put it on the bike and see how it gos?? i would love to ride it more but i work from home and only get to ride weekends

[ste7ios 469]

At 12.45V (Open Circuit Voltage - OCV at 25ºC) your Yuasa is at less than 50% of its capacity.

 

It is suggested to replace a battery when it can not hold half of its capacity because it may not start an engine on a cold day. (Thankfully, NC is an easy starter!)

 

With your riding habits I would suggest to use a battery maintainer like CTEK or Optimate to reduce the sulfation effect that deteriorates the battery life.

 

 

Yuasa's Technical Manual

[trisaki 2,029]

the main reason why these battery conditioners were bought out was for bikes with alarms fitted , if say for instance you bought the bike brand spanking but didnt use it for a month or two but the alarm was on / the battery would be more or less knackered because the alarm would have dragged the battery down , so bikes with alarms fitted and left without being used for a month or two will benfit from plugging into an optimate type charger , bikes without alarms can go more then 3 or more months without being charged and can sometimes be over charged because they arnt being drained / or if no alarm fitted just disconnect one of the leads  that way it will  discharge a lot slower than leaving it connected

[Derek_Mac 1,404]

Yuasa reckon that if the battery is less than 12.6 volts it needs charged.

  Also, the rate that they self discharge at depends on the ambient temperature.

[ste7ios 469]

Sulfation stops only when the battery is 100% charged (OCV: 13.0V). If you don't maintain it fully charged, sulfation will grow exponentially. Small parasitic draws, short rides, the difficulty of lead-acid for a full charge, are enough reasons for me to use a maintainer. (Not trickle charger / battery tender type, they overcharge the battery).

You may have enough charge to start the bike after 3 months but sulfation will deteriorate battery's performance - capacity.

It's not strange why many batteries last less than 50% of their lifetime... (Usual lifetime is 5 years.)