What kind of battery charger should I get to maintain my battery for the 8 months "off season"?

[WaterEnthusiast]

Hi,

I find it amazing the amount of contradicting information I get. I live in a city where my Sea-Doo will be out of the water for 8 months. I'm told I need to "maintain" my battery throughout this period. I've heard and read various things:

1- The guy at the BRP dealership told me that I shouldn't take my motorcycle battery charger (that has either 2 amps or 6 amps) because 2 amps is too much for this sort of battery. I need something that gives less than 1 amp.

2- A mechanic that did other work on my Sea-Doo told me: "You motorcycle battery charger is fine at 2amps. Just plus it for 24h and then take it off".

3- The guy at Canadian Tire who had about 15 different models to sell told me: "You need to take a "marine" charger. Marine batteries support "deep cycles" (whatever that means" so you need a charger that supports it.

I'm confused. It seems every have an opinion on the matter. I guess the right thing for me to do is ask the same question to the Internet and see it I get even more diverging opinions!!

Attached are:
1- The charger recommended at the BRP dealership.



2- My "old" motorcycle battery charger


3- Low-current charger lent to me by a friend



4- The "marine" charger suggested at Canadian Tire



5- Other options, with varying costs, that the CT clerk said were not appropriate for my Sea-Doo (except the ones marked "waterproof" he said..



Looking forward to suggestions.

Thanks

 

[Sportster-2001-951C-Stock]

I use battery tender 800's b/c they're waterproof but I think it's smaller brother works well too.

At home, I use a timer to power AC supply on 10 min/week or I just plug it in briefely once/month and count the seconds till green light comes on, usually less than 30 seconds. Last year before splashing it took much more time, maybe my 5yr old battery needs replacement?

 

[Rikky001]

I use a CTEK MXS 5.0 and use it for my PWC, ATV, cars and boat.
My PWC is only used 3 months a year, and most of the time on the CTEK lifeline. Never have to change a battery anymore.
Charger Selection Chart

 

[mikidymac]

The one in your picture of the “Nautilus” that says Battery Tender is the one you want.

It’s computer controlled, low amp and is smart enough to be left on 24/7. It will charge, float, cycle and rest depending on the battery.

I leave mine connected all year and only disconnect when using the watercraft.

I get at least 5 years out of my flooded battery and am still using my Optima Blue Tops from 2006.

 

[WaterEnthusiast]

But the nautilus only goes down to 2A. I should dismiss what they told me at the dealership about requiring less than 1amp for maintaining charge..?

Thanks

 

[benjilafouine]

On the shelf below the Nautilus charger on one of your pictures, there is the "Battery tender plus" at 1.25 amp. I have one exactly like that from Canadian Tire and I use it for my ATV and Sea-Doo and all other small batteries. It will charge then it will stop charging and keep the battery in a floating stage. I left that tender connected to my ATV for weeks at the time with the battery connected to the ATV when it was in my unheated cabin (so that it starts well at -20 C) and I never had an issue (same battery size as my Sea-Doos).

In my opinion, a 2 amp would do fine as well but since the computers (ECU) on Sea-Doo's tend to be a bit "fragile" according to many on this forum, if you are to let a tender plugged in over a long period of time, your battery should be disconnected.

I also have a cheap "Motomaster" 1 amp charger that I occasionally connect to my Sea-Doo for one night during the summer season without disconnecting the battery, especially if the Sea-Doos doesn't run much.

Also, I live in Canada as well (Quebec) and my Sea-Doo is in warm storage for 7-8 months too (I had one outside a few years back for all winter). I fully charge the battery disconnected before storing it away in the fall and I am now about to start reconnecting my battery tender for several days on each of my skis and cleaning them up. I don't think that a charger should be connected for 8 months, even a tender one (loss of time in my opinion especially since these batteries usually don't last very long, like 3 years (5 if you're lucky).

 

[mikidymac]

But the nautilus only goes down to 2A. I should dismiss what they told me at the dealership about requiring less than 1amp for maintaining charge..?

Thanks

And that is why I said to get the Battery Tender.

You are only trying to keep the battery topped up, not charging a dead battery, not boosting to start.

Once again........Battery Tender.

 

[benjilafouine]

Three years ago, my Sea-Doo stayed outside all winter under heavy snow at -20 C. When I pulled it out of there (there was still snow), I just connected the battery at it started instantly! I charged the battery afterward!

 

[Macker29]

Three years ago, my Sea-Doo stayed outside all winter under heavy snow at -20 C. When I pulled it out of there (there was still snow), I just connected the battery at it started instantly! I charged the battery afterward!

I had a mechanic tell me that charging your battery during the winter is a waste of time/energy. He said just turn the battery switch off and worry about it in the spring. Started my boat a few days ago on the first attempt after sitting for 5 1/2 months (and we had a brutally cold winter here). As you said, now I will start trickle charging it as the season approaches

 

[ski-d00]

The cold doesn't really "hurt" the battery long term. However, the cca is lower at lower temperatures which is why your car may not start on cold mornings. Heat is the real enemy of batteries and will kill batteries which is why hot climates go through batteries quicker than average climates.

To the post above, charging a battery is a waste of time over the winter if it doesn't need a charge. Healthy newer batteries will maintain a charge all winter and don't really need charged but most batteries are not new. Time will drain a battery if it isn't newer and in good shape. Draining a battery is hard on the battery life so if your battery isn't new, then you need to keep it charged throughout the winter. Most average batteries will only need a low amp overnight charge every 6 weeks. Overcharging is worse than letting it sit because it keeps it hot.

Smart chargers are the way to go. They maintain the battery where they need to be regardless of time and temperature.

 

[mikidymac]

Also in cold climates the charge of the battery affects the freezing point. If left outside you can destroy the battery by freezing it.
A fully charged battery has a electrolyte freezing point of -80F whereas a discharged battery has a freezing point of 20F.

 

[Doctor_Venkman]

Deltran12-Volt Battery Tender Jr. Is what I've used for the past few seasons for my lawn mower and 2 SeaDoo batteries and, so far, has started each of them on the first try. I pull the batteries from the mower and SeaDoos and maintain them in my garage. Home Depot sells them for $40 but occasionally you can catch them or on Amazon for around $25.

 

[Sportster-2001-951C-Stock]

I'm sure Canadinans know all about frozen batteries. I don't think I've ever seen one freeze even total a total junk one in dead of winter.

ctek makes very sophistocated chargers i believe, constant current adjustable and 3 or 4 stage? The deltrans are pretty good but there are better that have incredible functions and cost more $$$. Why leave it plugged in constantly, seems like a waste to me besides other benefits of cycling them.

 

[Rikky001]

CTEK does everything. Just take out the battery if you don't use it that long and keep it on the CTEK most of the time.

 

[mikidymac]

So does the $40 Battery Tender. My optima blue tops are still going strong from 2006. Yes, that’s correct 13 year old batteries still working in my boat and have been on a battery tender whenever they aren’t in the boat.

Although it won’t work with lithium batteries.

 

[Sportster-2001-951C-Stock]

So does the $40 Battery Tender. My optima blue tops are still going strong from 2006. Yes, that’s correct 13 year old batteries still working in my boat and have been on a battery tender whenever they aren’t in the boat.

Although it won’t work with lithium batteries.

Absolutely, my Deltrans have worked great for years. The CTEK's design is newer and have excellent reviews by the battery nerds.

Longest L/A battery life I've had were almost 20 years old. Well, those two batteries are gone now incredibly within months of each other but it was true.

Have a great day, guys!

 

[LikeabossTM]

Battery tender or ctek are perfect for your battery. I love my ctek, I use it to keep my car battery topped off when I'm not going to be driving for a couple of weeks, as well as for my powersport batteries. Set it and forget it.

You can see that it has different settings for the size of battery. My seadoo battery is a typical 19ah lead acid, so I set it to the motorcycle setting which pushes 0.8 amps. Of course it goes into maintenance mode and stops charging when the battery is at 100%.

I've included a pic of the reference charging rates for various battery capacities and charge times at different amperages, from the battery manufacturer. Notice that the highest amperage recommended for these small batteries is 2A.

 

[Sportster-2001-951C-Stock]

Battery tender or ctek are perfect for your battery. I love my ctek, I use it to keep my car battery topped off when I'm not going to be driving for a couple of weeks, as well as for my powersport batteries. Set it and forget it.

You can see that it has different settings for the size of battery. My seadoo battery is a typical 19ah lead acid, so I set it to the motorcycle setting which pushes 0.8 amps. Of course it goes into maintenance mode and stops charging when the battery is at 100%.

Yes, that's the one I had in mind. As long as charge rate doesn't exceed 30% of Ah capacity (C-rate spec'd on a 20 hour capacity rating), no damage occurs. This means we really don't have to worry much about having a charger being too large b/c most aren't, but where battery chargers fail is it must drop to float voltage once saturation occurs.

For instance, a 100Ah car battery can absorb 30A peak charge rate and a 10Ah battery can absorb 3A peak charge rate. So you can safely charge even the small battery using a 3A charge rate.

Charging Information For Lead Acid Batteries – Battery University
Charging Batteries with a Power Supply