# Question: Charging my Boat's Battery



## cwbarner (May 14, 2011)

I have an EverStart marine battery which I charge with a Schumacher 10/2 amp auto/manual charger.

Why does the needle read 50% charged when it's set for 10 amps but shows almost 100% charged when it's set for 2 amps?

Thanks.


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## GoldDot40 (May 14, 2011)

Not sure why it would do that. Your charger must be an older analog unit? Is it suitable for charging a marine/deep cycle battery? The 2 amp mode on those usually aren't for 'trickle' charging....but more for small (ATV, lawnmower) batteries. Use the 10amp setting.

My Schumacher charger has a Regular, Deep Cycle, and AGM mode. Then it has a 15 amp, 10 amp, and 2 amp option. I charge my boat battery using the 10 amp + Deep cycle settings.


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## Dead Eye Eddy (May 15, 2011)

I used to have that same charger.  I used the 2 amp setting because I thought it was for trickle charging.  It never seemed to get the battery fully charged.  I invested in an on board charger, and it's some of the best money I've ever spent.  I got 4 full seasons out of my last cranking battery and 3 full seasons out of my last trolling battery.  If I hadn't forgotten to plug them in last August when I fished last, they may have lasted this season as well.  I just replaced both of them before my first fishing trip 2 weeks ago.  I didn't even try to charge them.  I figured it was time for new ones anyway.  I'm on my second on board charger.  I got 3 years out of the first one, and I'm on the 4th year with the 2nd one.  For about $25-40 per year ($100-125 for a 2 bank charger), my batteries last longer and I don't have to worry about settings and alligator clips and crap like that.


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## cwbarner (May 15, 2011)

It is analog.

I set it at automatic/maintenance-free/deep cycle.  That's where it is when the charge level reading changes.

I only run a 28# trolling motor for a 12ft john boat off it so I haven't been charging it after each trip.  When I do charge it, I have set it at 2amp overnight.  Sounds like I should switch to, and maybe rely on the guage for, the 10 amp setting.


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## GoldDot40 (May 15, 2011)

cwbarner said:


> It is analog.
> 
> I set it at automatic/maintenance-free/deep cycle.  That's where it is when the charge level reading changes.



Yep, automatic mode insures that you won't over charge the battery. When it reaches full capacity, it goes into a 'maintain' mode. It can sit there on charge for weeks to months without hurting anything.

My trolling motor is a 30lbs thrust unit and I charge the battery every time I come off the water, even if I was only out there a couple of hours.


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## Fletch_W (May 17, 2011)

cwbarner said:


> I only run a 28# trolling motor for a 12ft john boat off it so I haven't been charging it after each trip.



That is very bad. You should charge it immediately after draining it, even if you think you only drained a little bit. Failing to do so accelerates the process of sulfation in your battery, particularly Everstart types. There are many scientific details on how and why this happens if you want to spend hours reading articles online. The simple point is to always recharge it as soon after using it as possible.


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## cwbarner (May 17, 2011)

I had always been told that it was best to let it drain as low as possible before recharging.  By doing so, you'd extend the life of the battery.  I'd heard the same about laptops, too, which I know are a completely different type of battery.

Fletch W, as per your advice, I did check it out, and you're right.  I'll start charging it after each use.  I appreciate the input.


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## Fletch_W (May 17, 2011)

cwbarner said:


> I had always been told that it was best to let it drain as low as possible before recharging.  By doing so, you'd extend the life of the battery.  I'd heard the same about laptops, too, which I know are a completely different type of battery.
> 
> Fletch W, as per your advice, I did check it out, and you're right.  I'll start charging it after each use.  I appreciate the input.



Hey, this is advice I got here months ago, researched on my own, and simply passed along. Soon enough, you'll be passing it along to someone else in this forum.

Furthermore, the reason your charger says 50% on the 10a setting and full on the 2a setting could be a result of sulfation in your battery


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