When using a battery charger is it best to remove the wires from ski battery first?

[rod_rod]

Hi All

When my ski sits for a month or more I always put a smart charger on the ski battery to charge up to 100% charged before taking the ski out.

I always remove the battery wires first so that the battery is isolated from the ski's electronics during the charging process, is this really required to remove the battery cables during charging?

My ski s cost me a lot of money and it only takes 5 minutes to disconnect the battery wires for safety as I would hate to short something out, although I doubt this would happen during the charging process with the wires attached, but I'm just not sure?? any comments appreciated...

By the way I never put a charger on any battery on any of my equipment at night time, and go to bed and hope for the best, would hate to wake up to a fire!

[Samband63]

Yes. The most appropriate method is to disconnect only the Negative lead off the battery during charging. The reason for removal of the battery lead and isolating it from the electronics is simply to take extra precautions to protect the ECM ( Control Module ) from accidental reversal of polarity during re-installation process of the battery or possible high current draw or any electrical surge thru the charger. I have personal experience of accidental reversal of the polarity and fortunately Ultra 300X protects the ECM by just blowing off the 15Amp fuse. But the only negative side of this removal of wire is that you will lose clock data on the cluster and you need to re set the clock.

[K447]

This question has been asked many times in the forums.

A primary risk to the watercraft electronics is from incorrectly connected charging equipment or from old or incorrectly configured chargers.

The other big risk is from incorrectly re-connecting the battery cables. This is when mistakes can happen.

Do not use dumb chargers or a charger meant for use on heavy car or truck batteries. A watercraft battery is much smaller and has less capacity to absorb overcharging so the charger must be a good match for the battery size and battery type.

Do not use a dumb 'trickle' charger. What is a trickle charge current into a truck battery is a significant charge rate for a watercraft battery. 2 amps is plenty for watercraft battery charging, a fast charge would be perhaps 8 amps.

A modern electronically controlled smart battery charger poses no significant risk to the watercraft, provided the charger is of good quality and well made. At a minimum you want a smart charger that adjusts the charge rate and switches to 'float' mode when the battery is well charged. During float mode the charger is not charging, merely maintaining the battery at full charge.

If you are using an AGM type battery (my recommendation) then make sure the charger is rated for use with AGM batteries.

Disconnecting and reconnecting the battery cables frequently introduces risks, such as wear on the bolts and nuts, possibly over tightening the battery cable bolt/nut or perhaps too loose (it can happen).

My advice is to permanently install a battery charger pigtail lead to the battery posts, adjacent to the main battery cable connections. Make sure all the battery connections are clean metal to metal, snug bolts without excess torque, then apply a dielectric protective grease/coating to keep corrosion away. Then leave them alone, except for occasional checks that they are not working loose.

Buy a battery charger that mates with the pigtail lead, making it easy to connect the charger. On my own watercraft the pigtail lead is zip tied up under the seat where I can easily reach it after lifting the seat. I leave the seat ajar while the charger is connected.



A really good smart battery charger has temperature sensing to adjust the charge voltage as batteries require different voltages at different temperatures to achieve 100% charge without overcharging. The precise voltages required will change with battery temperature.

While a few really good chargers have a separate temperature sensor probe that you would put next to the battery, most smart chargers just have a temp sensor inside the charger itself, the idea being that the battery and the charger will be at roughly the same temperature. If the charger is in the shade and the watercraft is in the sun (or vice versa), this could lead to incorrect charging.

If the charger is not temperature compensated at all then very hot or cold temperatures can cause incorrect charging.

[rod_rod]

Thanks, Excellent reading/info, appreciated

[Wolf714]

Excellent post K447. Plus one on the pigtail. I leave my Optimate charger on 24/7 when away.

[rod_rod]

Yes. The most appropriate method is to disconnect only the Negative lead off the battery during charging. The reason for removal of the battery lead and isolating it from the electronics is simply to take extra precautions to protect the ECM ( Control Module ) from accidental reversal of polarity during re-installation process of the battery or possible high current draw or any electrical surge thru the charger. I have personal experience of accidental reversal of the polarity and fortunately Ultra 300X protects the ECM by just blowing off the 15Amp fuse. But the only negative side of this removal of wire is that you will lose clock data on the cluster and you need to re set the clock.

Thanks for the input appreciated. So we have two different approaches to this question of "to disconnect the battery cables leading to ECU etc, or leave them on" during charging. I guess it comes down to personal choice, I think at this point I will continue to disconnect the battery and keep it isolated during charging even though I have the correct wires/cables that were supplied with my Daltron Battery Tender (Charger) Um.... maybe I might install the Daltron cables later in the same configuration as K447, LOL so many choices!

[K447]

Yes. The most appropriate method is to disconnect only the Negative lead off the battery during charging. The reason for removal of the battery lead and isolating it from the electronics is simply to take extra precautions to protect the ECM ( Control Module ) from accidental reversal of polarity during re-installation process of the battery or possible high current draw or any electrical surge thru the charger.

I have personal experience of accidental reversal of the polarity and fortunately Ultra 300X protects the ECM by just blowing off the 15Amp fuse. But the only negative side of this removal of wire is that you will lose clock data on the cluster and you need to re set the clock.

If the battery remains connected at all times there can be no reversal of polarity.

The pigtail charger wire is polarized at the connector so no polarity reversal possible.

The smart charger itself should have polarity detection and it will not energize if polarity is reversed.

Polarity reversal is only a risk, in my view, when the battery cables are disconnected. Leave them connected and the risk is not present.

The quality of the charger is important. A good charger will not create voltage spikes, surges or reverse polarity risks for the watercraft electrical system.

In addition, the battery provides a solid defense as it will absorb voltage and current spikes from the charger, within reason. AGM batteries are particularly good in this regard as they can absorb high charge currents, should the charger err in this regard.

There is more risk of electrical pulses and spikes from frequent disconnect and reconnecting of battery cables. Messing with tools and small wrenches around the battery involves some risk of mistakes and user errors. The more often you are in there, the more chance of causing trouble.

The battery itself, while connected to the heavy watercraft cables, provides a solid voltage stabilizing function and limits the havoc even a misbehaving charger can impose.

In my view it is not 'safer' to disconnect the battery frequently, or really ever during the riding season.

Install a high grade AGM battery, include a charging pigtail and tie it out of the way, but accessible. Then enjoy the riding season. A good AGM battery should not lose much charge while the machine is sitting between rides, unless that duration is many weeks.

My own watercraft generally do not see a charger at all during the riding season, there is just no need.

Use the charging pigtail as needed to charge the battery should the need arise.

[K447]

If using a battery charger is it best to remove the wires from ski battery first?

My perception is that damage risk in regards to battery connections comes from, among other things;

Connecting a battery cable and allowing the contact to bounce or reconnect rapidly multiple times in rapid succession. This can easily happen while struggling to get the little bolt threaded into the battery post. Connect the battery cable firmly, hold it firmly in place, insert and snug the screw.

Connecting or reconnecting a watercraft battery without carefully checking the polarity of the battery posts with the battery cables.

Additional risk is present if the replacement battery has the opposite polarity as the previous battery. Watercraft batteries are sold with the positive post at one end or the other. Which end is which can be the opposite of the battery you just removed, so pay attention to the positive terminal marking on the new battery.

Connecting an external battery jumper pack, jumper cables to a car, truck or any other battery sitting outside the hull. Removing or disconnecting a dead battery and attempting to start the engine using any of these methods.

Messing about with an aged or discharged battery, trying to revive the old battery or just 'get it started' without installing a healthy and fully charged battery as step one.

The low risk approach is to install a new or known healthy battery, thereby not risk screwing up expensive watercraft electronics trying to save, boost or otherwise reuse a crappy battery.

[jetdave56]

Rod if your not going to use the ski for a month or more just take it out of the ski and keep on a trickle charge in let's say your garage no electronic worries ,on the charger you should be at least 13.25V check it from time to time ...

when removing it's neg first when installing positive first,when battery is installed on ski should read at least 12.50v when not running and 13-14v v on and idling..

[wotman]

Wow ive left the ski for 12 months without charging and battery was fine.
If you ride once a month,you should never have to charge.

[Rescue1]

I put the pigtail on and use a smart solar charger(There isn't any power on that side of the yard). But pretty much what K447 said..

[K447]

Wow ive left the ski for 12 months without charging and battery was fine.

If you ride once a month, you should never have to charge.

How long a battery can sit without needing recharge greatly depends on the battery type and battery condition. A healthy AGM battery should hold about 85% of full charge for many months.

A traditional lead-acid battery may self discharge itself in less than four months.

If the watercraft imposes a parasitic electrical load (battery drain) then the battery will discharge over time. How fast depends on the electrical drain and the initial battery health.

I agree that even occaisional riding should be enough to maintain battery charge levels, IF the battery itself is healthy and not degraded from age or abuse. And of course the electrical system in the watercraft needs to be working correctly in regards to battery charging.

[K447]

Rod if your not going to use the ski for a month or more just take it out of the ski and keep on a trickle charge in let's say your garage no electronic worries ,on the charger you should be at least 13.25V check it from time to time ...

when removing it's neg first when installing positive first, when battery is installed on ski should read at least 12.50v when not running and 13-14v v on and idling..

Trickle charge is an outdated terminology dating from many decades ago when liquid filled lead-acid batteries in cars and trucks had a fairly high rate of self discharge.

Those old-school batteries would lose stored energy so easily that a 'trickle charger' could continuously pump maybe 1-2 amps into the battery and it would not quickly overcharge. Hence it was common practice to connect a small output charger and just leave it running, with no electronic voltage/current controls or timer.

Those big old batteries would just sit there and soak up the current flow. They would slowly out gas and lose water, so topping up the battery cells with distilled water was considered part of regular car maintenance.

Compact modern watercraft sealed batteries don't work like that. Overcharging is to be avoided, hence the imperative to use an electronic smart charger that will control the charging and properly maintain the battery state of charge.

When measuring battery voltage to check state of charge, there are factors which affect what the correct voltage should be. Battery type matters, AGM batteries have a higher 'resting voltage' than lead-acid.

After charging, the battery must 'rest' for multiple hours before the voltage at the battery posts settles down. Measuring the battery voltage shortly after disconnecting a battery charger will show a misleading higher voltage. The battery must sit for quite a while before the measured voltage is useful for checking the state of charge inside the battery.

Battery temperature also matters. Normal 'room temperature' voltage spec for a battery is circa 25C. Very hot or cold batteries will measure different voltages, yet be correctly 100% charged.

Check the manufacturer specifications for the battery brand and model you have installed, and use that to determine what the measured voltage means for your battery.

For example, 12.5 volts battery resting voltage might indicate a full charge on a lead-acid battery yet the same 12.5 volts on an AGM battery could indicate it needs charging.

[Wolf714]

I only keep my recreational vehicles for 2-4 seasons and the stock Yuasa batteries are always in good condition when I sell them. So I have never seen the need to buy AGM batteries. But I always keep a charger on when not using them since conventional batteries can be ruined very easily if discharged completely and left that way for a period of time.

K447 is exceptionally knowledgable on this subject. Read and heed.

[rod_rod]

Yes. The most appropriate method is to disconnect only the Negative lead off the battery during charging. The reason for removal of the battery lead and isolating it from the electronics is simply to take extra precautions to protect the ECM ( Control Module ) from accidental reversal of polarity during re-installation process of the battery or possible high current draw or any electrical surge thru the charger.

I have personal experience of accidental reversal of the polarity and fortunately Ultra 300X protects the ECM by just blowing off the 15Amp fuse. But the only negative side of this removal of wire is that you will lose clock data on the cluster and you need to re set the clock.

If the battery remains connected at all times there can be no reversal of polarity. The pigtail charger wire is polarized at the connector so no polarity reversal possible. The charger itself has polarity detection and it will not energize if polarity is reversed.

Polarity reversal is only a risk, in my view, when the battery cables are disconnected. Leave them connected and the risk is not present.

The quality of the charger is important. A good charger will not create voltage spikes, surges or reverse polarity risks for the watercraft electrical system.

In addition, the battery provides a solid defense as it will absorb voltage and current spikes from the charger, within reason. AGM batteries are particularly good in this regard as they can absorb high charge currents, should the charger err in this regard.

There is more risk of electrical pulses and spikes from frequent disconnect and reconnecting of battery cables. Messing with tools and small wrenches around the battery involves some risk of mistakes and user errors. The more often you are in there, the more chance of causing trouble.

The battery itself, while connected to the heavy watercraft cables, provides a solid voltage stabilizing function and limits the havoc even a misbehaving charger can impose.

In my view it is not 'safer' to disconnect the battery frequently, or ever during the riding season.

Install a high grade AGM battery, include a charging pigtail and tie it out of the way, but accessible. Then enjoy the riding season. A good AGM battery should not lose much charge while the machine is sitting between rides, unless that duration is many weeks.

My own watercraft generally do not see a charger at all during the riding season, there is just no need.

Use the charging pigtail as needed to charge the battery should the need arise.

Great info thanks!