Battery Tenders

**Cigalert** · 02-17-2014, 07:32 AM

I decided to put a tender on the boat after I pulled my stupid. I have 2 Interstate Deep Cycle SRM-24's.

I connected 1 battery and put my switch to "all". And most important...switched off the breaker for the stereo.

Here is the tender...

Anyone have any experience with these? Pros/cons/problems?

**Stainless** · 02-17-2014, 07:36 AM

I have a two bank made by battery tender on mine because it is 2 separate systems. I'll take a pic when I get back.

CH3NO2

**ChumpChange** · 02-17-2014, 07:38 AM

My neighbor works for the distributor. No issues here. I'm more of a Chicken Tenders fan.

**Stainless** · 02-17-2014, 07:48 AM

Eli has a Tinder also.

CH3NO2

**HB Vic** · 02-17-2014, 08:26 AM

Honestly I don't think leaving your perko on in any position is a good idea. Too many bad things can happen to a unmonitored boat or RV or anything for that matter.

You can use diodes to charge both batteries with the switch off and that will keep the batteries separate with the switch in the one batt position. But I would fuse the tender as well.

As far as trickle charging, I'm not a fan. But then again its been too long since I was in the battery business, so things may have changed, but I doubt it.

Trickle, float, tender, whatever they want to call it is still causing current flow in the battery. Current flow, over time, will age the cells. Batteries age even without a charge, so even a float charge will age them a little faster. I prefer to switch mine completely off and if they die, charge them back up when I need them. In the past 5-6 years I think I've had to use a charger 1 or 2X. And the boats have sat for upwards of 2-3 months.

**Cigalert** · 02-17-2014, 08:33 AM

Originally Posted by Hotboat

Honestly I don't think leaving your perko on in any position is a good idea. Too many bad things can happen to a unmonitored boat or RV or anything for that matter.

You can use diodes to charge both batteries with the switch off and that will keep the batteries separate with the switch in the one batt position. But I would fuse the tender as well.

As far as trickle charging, I'm not a fan. But then again its been too long since I was in the battery business, so things may have changed, but I doubt it.

Trickle, float, tender, whatever they want to call it is still causing current flow in the battery. Current flow, over time, will age the cells. Batteries age even without a charge, so even a float charge will age them a little faster. I prefer to switch mine completely off and if they die, charge them back up when I need them. In the past 5-6 years I think I've had to use a charger 1 or 2X. And the boats have sat for upwards of 2-3 months.

I've never used a tender on a boat for anything but forgetting to switch everything off last trip kinda got me irked if this was a dedicated boating trip.

The charger is fused but I was concerned with leaving the switch on (hence the original post). I can see where the batteries are going to work more....loss of charge, tender picks up and it's a constant up and down cycle toward the top of the charge.

I'm gonna let it roll for a week or 2. Maybe just keep my starting battery on the tender from time to time.

**28eliminator** · 02-17-2014, 09:03 AM

I have this 3 bank maintainer/charger installed in my Boat. I have 2 grp 27's and 1 grp 24 that it maintains all independently. The Boat is plugged into it all the time it's not on the water, and so far so good.

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Name: 2013-06-12 19.38.41.jpg
Views: 380
Size: 86.8 KB

**Bobby V** · 02-17-2014, 09:13 AM

I have the same tender for my golf cart, rhino, Tahoe and for my 4 boat batteries. No problems so far. I do put the switch on OFF though.

**Slacker** · 02-17-2014, 09:21 AM

I have to agree with Hotboat. Any charger that does a Constant Trickle charge is not good for the battery, it can boil a battery. If you want an inboard charger do what 28elim. did, that charger shuts completely off when the batteries are at full charge. I would leave it plugged in for a couple days and then unplug it and would do that every couple weeks. Kinda makes be nervous to leave it plugged in all the time but thats just me.

**Cigalert** · 02-17-2014, 09:31 AM

Originally Posted by Slacker

I have to agree with Hotboat. Any charger that does a Constant Trickle charge is not good for the battery, it can boil a battery. If you want an inboard charger do what 28elim. did, that charger shuts completely off when the batteries are at full charge. I would leave it plugged in for a couple days and then unplug it and would do that every couple weeks. Kinda makes be nervous to leave it plugged in all the time but thats just me.

This one stated it shuts off after its full. Is that not the case?

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