Battery Questions

[Jax750]

I read somewhere that I shouldn't use my car charger to charge my Monster battery. If they are both 12 volt, why can't I use it? I don't have a problem yet but I'm sure someday I will need to charge it. I will probably buy a battery tender, the previous owner said a connector was already installed.
I also read that you can jump the bike from a car, is this really okay?
Thanks in advance for any replies.

[duality]

Both questions were covered before on this forum, but quick answers are:

1. You cant use regular car battery charger because it charges at 10 - 40 Amps, which can damage bike battery. You need trickle charger or battery tender that chargers at around 1 Amp.

2. You can start your bike from car's battery, just make sure that car is *NOT* running while you jump start your bike. Otherwise car's alternator can damage your bike's circuitry (again due to high amperage).

[Jax750]

Thank you very much for the info, I always try a search first but I was using the wrong search button and coming up with zero matches every time.
Anyway, thank you for answering my questions, that was very helpful. This forum has really been a great resource for a first time Ducati owner.

[dankatz]

My car battery charger has options to charge at 10A or 2A. 2A would be fine for the bike. If you already have a pigtail (SAE connector) best to get a $30 battery tender. That's what I did. It charges at 1.25A then switches to 0.75A for trickle charge.

[Capo]

This explains how the battery tender type chargers work, in this case the Optimate.

a) The CHARGING stage (yellow LED) delivers a constant current of 0,6 Amps into the battery, whose progressively rising impedance will cause the charging voltage to increase until 14,3V, when the OptiMate will start the absorption & verification stage.
b) The charging voltage is now limited at 13,6V during 30 minutes. Should the monitored voltage reduce by 300mV or more, or the current drawn by the battery exceed 200mA during these 30 minutes, the programme reverts immediately to the main CHARGING stage & 4) a) is repeated. The OptiMate thereby automatically ensures a full charge before starting the maintenance stage.
5) The maintenance (float voltage) stage includes an automatic test for battery self-discharge, repeated during 30 minutes in each hour as long as the battery remains connected. During 30 minutes no current at all is offered to the battery, and the circuit just monitors the battery voltage for stability. If the battery voltage falls below 12,3V the red WEAK LED in the TEST panel will indicate a problem but the battery will then continue to be maintained in float voltage mode (13,6V) until disconnected. See separate clause on red LED indications below. If the battery voltage remains greater or equal to 12,3V during the 30 minutes test the green GOOD BATTERY LED will indicate and continue doing so unless a failure of a subsequent test causes the red LED to indicate.
With the green LED indicating, during the other 30 minutes of each hour, the OptiMate allows the battery to draw up to 200mA of current to support any connected accessories or alarms, or losses due to deteriorating vehicle wiring

[yodrei]

I have a trickle charger (Deltran Battery Tender Jr.), but it says it will not work if the battery has dropped below 3V. This seems to be the case for my battery. Any ideas on how to charge it up to 3V or more? Can I hook it up to another disconnected motorcycle or car battery for a while? Thanks.

[kaffetero]

Just to share a recent "learning experience" (aka screw up):

2007 Monster 695 - here's the scenario:

- Park the bike in the garage overnight with key in "Park" position (doh!).
- Battery is dead next morning.
- Attempt a jump start from a running car, but...
- Reverse connections (accidentally :-( ) and get a spark from the jumper cables when connecting batteries.
- Straighten out cables and try again, no joy.
- Take bike battery out and put on the bench connected to a standard battery charger (~3 hrs).
- Put battery back in bike, no joy (meaning no clicks, buzzing, lights, nada).
- Check battery voltage, seems ok at 12.3v at both the battery terminals and the tender connector (indicating battery connections are alright, maybe)
- Check fuse panel fuses, all ok. Initial diagnosis is there's a blown inline fuse or fusable link somewhere.
- Lots of online research, ruling out concerns about anti-theft system kicking in, blown circuits, burnt ecu, ignition lockout a'la kickstand switch, etc.
- Found a "parts list" document that has an exploded diagram of the wiring system showing an inline master fuse on the positive battery lead, just rear of the battery box.
- Bingo!, blown 30A fuse.
- Replaced fuse, and bike started normally.

Seems I was lucky as I found a number of horror stories about reversing polarity frying the entire electric system, battery chargers damaging the bike or the battery, etc. and I got away with just a blown fuse.