"Battery Tender" questions

[GlobalRider]

There are two thoughts on this that battery charger/maintainers use.

Some will enter and remain in a float/maintain mode after reaching a full charge.

Others will go through the bulk and absorption stages over and over again. They shut off when the battery is fully charged and when the battery self discharges to about 12.6V, the charger will re-initiate the charge sequence.

My personal opinion based on experience and testing at work is that the latter is a better method for long battery life.

Just a follow-up.

Earlier this year, I tested both my CTEK 3300 units at work. They were charging a new battery that was confirmed good. A Graphtec data logger was used.

My CTEKs did not enter any "maintenance mode". They simply charged the battery to 14.3V and then switched off, turning back on at 12.65V.

But as I mentioned above, I prefer this method of battery maintenance...its just not doing what they advertize.

[_CY_]

Just a follow-up.

Earlier this year, I tested both my CTEK 3300 units at work. They were charging a new battery that was confirmed good. A Graphtec data logger was used.

My CTEKs did not enter any "maintenance mode". They simply charged the battery to 14.3V and then switched off, turning back on at 12.65V.

But as I mentioned above, I prefer this method of battery maintenance...its just not doing what they advertize.

switching off current when xx volts is reached is the sign of a well made charger. vs lessor chargers will continue to deliver a small current even after fully charge condition is reached by battery.

yes your battery can be overcharged even by a milliamp current if left for extended periods.

AGM has a self discharge rate of about 1-2% per month. LiFePO4 (without BMS) has a self discharge rate about 1-2% per year. conventional lead acid self discharge can be 1-3% per week.

assuming your bike's parasitic drain is next to zero. over the winter NO battery tender is needed for AGM and LiFEPO4 batteries.

My LiFePO4 testing thread on ADV

[GlobalRider]

assuming your bike's parasitic drain is next to zero. over the winter NO battery tender is needed for AGM and LiFEPO4 batteries.

Unfortunately, very few vehicles have anything near a zero mA current drain. Even a 10 mA or 20 mA discharge rate will deplete the battery over the winter, considering the capacity of most motorcycle batteries is below 20 Ah.

Its one of the reasons why I don't put much stock in VRLA batteries. Their low rate of self discharge and high CCA are of little importance to me when my parasitic drain is far greater and I'm not operating in sub-freezing temperatures.

[_CY_]

Unfortunately, very few vehicles have anything near a zero mA current drain. Even a 10 mA or 20 mA discharge rate will deplete the battery over the winter, considering the capacity of most motorcycle batteries is below 20 Ah.

Its one of the reasons why I don't put much stock in VRLA batteries. Their low rate of self discharge and high CCA are of little importance to me when my parasitic drain is far greater and I'm not operating in sub-freezing temperatures.

reduce drain to zero ... disconnect battery. then NO battery tender is needed for AGM and LiFePO4.

this is assuming one if putting a bike away for the season. otherwise disconnecting battery would be a PITA.

[VTBeemer]

Good info above. I have the Beemer charger and unless I plug in the charger plug into the Powerlet plug with the charger plugged in - and then turn on the bike key for 10 seconds -the charger will not charge. The Canbus system turns off the path to the plug.

[thumperbum]

I'm with ya VTBeemer
Spent Memorial weekend installing P3 Brake Lights, an IQ-170 Lighting Controller, BlingLights LED driving lights, two 6 LED strips low on the inside front fender and an AutoSwitch AS7 to kill the lights if needed. I drained down the battery during the install by 2 days of turning on/off the ignition without starting the 08 RT1200. At some point I switched on the Grip Heaters and the bike wouldn't start for the test ride. Soooo I plugged in my trusty trickle charger to the front PowerLet Socket. Of course the AutoSwitch LED lit up, telling me it was being powered up by the battery charger. It was flashing from quick pulses to steady red about every minute, obviously it didn't like the charger!
I cut the quick disconnect off the $25 PowerLet adapter and engineered my own Charging Pigtail. I found a existing 1/4 hole in the Fairing Mount and slid my Heat Shrink Covered charging wire through the hole and connected to the battery. I left the cable room to slide in and out a inch or two for use. It slides back in and tucks under the Passenger Seat where the Seat Heater Switch is mounted. Works Great!

[05Train]

I just ran an SAE tender pigtail off of the battery. Took all of about 30 seconds, and I don;t have to worry about it. I can power my Slime compressor from it as well.

[PGlaves]

I just ran an SAE tender pigtail off of the battery. Took all of about 30 seconds, and I don;t have to worry about it. I can power my Slime compressor from it as well.

Fused I hope.

[gfergeson]

I would like to buy a tender for this bike, and believe that BMW makes one that plugs directly into the accessory socket. I cannot find it on their website and so if anyone can tell me about these, what they are called and where to buy one or at least view it online I would appreciate it .

Thanks,

Grant

[71243]

I have Odyssey batteries in all three of my motorcycles. I have been riding my 04 Roadster the most, and as such I let my two Kawi Cruisers sit,[my bad] and the batteries went dead. Plugged them in to a B/Tender for about 24 hours each, and both started effortlessly.

[marchyman]

I would like to buy a tender for this bike, and believe that BMW makes one that plugs directly into the accessory socket. I cannot find it on their website and so if anyone can tell me about these, what they are called and where to buy one or at least view it online I would appreciate it .

If you really want the BMW name you can find it here: http://www.ascycles.com/detail.aspx?ID=2678 as well as other places. The key to your google searches is to add CANBUS to the search terms, i.e BMW CANBUS battery charger.

Another charger that can also plug into your accessory socket at about 1/3 the price of the BMW charger is the Optimate 4 dual (must be the dual version to work via the accessory socket of your bike). Example: http://www.amazon.com/dp/B004PPXZIA

[GeneT]

My new bike came with a dealer installed pigtail connected to the battery with an SAE connector to accommodate a battery tender unit. I did not request this and only found out about it when I took a pigtail in with me at the 1000 km service. When I asked them to attach it, they showed me their standard item already installed.

I have the Sr unit that has a storage mode - Jr probably does too. Just leave it connected all winter.

I dug this quote from an old post regarding late model bikes with on board computers and it sort of answers my question regarding battery tenders. It appears here that the selling dealer has connected a pig tail directly to the battery whereas allowing the owner use a more conventional battery tender as opposed to spending $166.95 for BMW's battery tender like my son in law bought for his GS.

In order for this to work properly the ignition key must be on when it is plugged in, afterwards the key can be turned off and the BMW battery tender will now talk to the computer and battery.

I know the owners manual says to disconnect the battery when connecting a battery charger to the battery to prevent damaging the electronics. However 12 volts is 12 volts, it does not matter where it comes from, so please can anyone explain how this type of connection can damage the electronics.

I have had several cars which were full of electronics and jump starting or charging was never an issue. In view of the BMW dealer making this connection the owners manual appears to be designed to sell BMW battery tenders.

What are your thoughts on this, I am not happy buying a 166.95 charger for my 2008 R1200 RT when I have three regular battery tenders here that work.

Thanks

[GlobalRider]

However 12 volts is 12 volts, it does not matter where it comes from, so please can anyone explain how this type of connection can damage the electronics.

Actually low 14s.

The only way that battery voltage can increase is by applying a higher charge voltage to it.

Furthermore, any sensitive electronics if it is properly designed would have filtering and over-voltage protection.

Attach the charge harness to the battery directly and stop worrying. Cripes, your alternator produces far worse voltage to the battery and your electronics is just fine...thanks to that big capacitor called a battery.

Gotta love the scare tactics used.

[GeneT]

Thanks Global Rider, since I posted this I found another member that has made this same connection with out any problem.