Anyone use those NOCO style battery jumpers with a deep cycle battery setup?

[MagentaLine]

So my boat has just barely enough space for two group 27 batteries. I just installed a below deck autopilot which is sure to push the limit on a single 100Ah battery. I'm thinking that weekend or even a day without recharging could put a single battery over the dreaded 50% capacity discharge prohibition. My thought is to have both batteries in parallel, either hardwired or just using the 1/2/both switch, giving me 200Ah total (essentially 100Ah usable). However, should that bank get depleted for whatever reason, I will not have a backup battery to start the motor.

I thought about going with lithium or adding a small third battery dedicated to starting but those options would necessitate installing a combiner, a new battery switch, rewiring the alternator from the starter directly to the battery bank, finding a spot to house another battery, etc etc. The Noco seems like an easy solution... if it works.

My concern with the Noco is if I were to connect it to a depleted 200Ah bank or even a 100Ah battery (if I used the switch to parallel the batteries), the current would rush out of the charger into the batteries too fast so that the system never has a high enough voltage to allow the starter to crank sufficiently. I've heard these gadgets work great even with larger engines, but I haven't heard of anyone using it with deep cycle batteries.

 

[SimonGH]

i think it would be fine. You're talking about traditional chemistry batteries here, correct (not LiFePo4 or anything crazy)? So basic lead acid?

Deep cycle just means they have thicker plates that allow for longer discharge. So if anything a conventional battery will take a charge "faster" than the deep cycle because there is more plate surface area. The NOCO's are designed for regular batteries, so I would suspect you'd actually get less current flow into a deep cycle.

Of course it does raise another issue - do your deep cycle batteries generate enough power to start your engine? Generally that's why you have a separate house and starter battery, so they can be different internal structure (one deep, one regular).

You could put a third battery for starting only, and just connect it to the house via a 12v-12v isolated DC charger... (I think)

 

[Zonker]

I used a tiny jump starter box on a very deadish car battery (wouldn't even turn on the dash lights).

3.0L V6. Started the car instantly. I think they must have some smarts to only activate when they sense a voltage drop i.e. the battery has to have some voltage not dead, dead.

Nothing special about a deep cycle battery versus a starting battery in a car except capacity. A big diesel pickup might have a ~75 A.hr battery for starting. And the larger jump boxes start them fine.

Any 100 A.hr deep cycle battery should have lots of CCA. Thicker plates just means less surface area which means lower CCA for a given size compared to starting batteries. But it doesn't mean it can't generate lots of amps to start an engine.

Here's a West Marine one that is 75 A.hr, 500 CCA

Deep Cycle Flooded Marine Battery, 75 Amp Hours, Group 24 | West Marine

Check out our Deep Cycle Flooded Marine Battery, 75 Amp Hours, Group 24 and more from West Marine!

www.westmarine.com

 

[MagentaLine]

FWIW. I've never had any issue starting a 2 or 3 cylinder yanmar with these type of batteries. I'm not talking about true golf cart type deep cycle.

The boat has a single group 27 100ah lifeline AGM battery and I was just going to add a second one and use it in parallel with another group 27 100ah lifeline AGM battery . My thought (this is shit I think about in the shower) was what if you had an enormous partially depleted battery bank and you connected a voltage source with low capacity at a higher potential. In theory, the voltage source at the higher potential (the noco) should deplete very rapidly; the only thing slowing it down from instantaneous depletion being the resistance of the wires and the internal resistance of the large battery bank until the voltages are equalized throughout the system.

 

[SimonGH]

I'm not a battery chemistry expert, but I believe it's the last part - you hit absorption voltage very quickly, but that doesn't mean you've recharged. There is a charge acceptance rate for AGMs that limits how quickly you can recharge. But I believe the voltage differential closes very quickly and thus your potential difference drops, slowing things down.

Dare I suggest you buy one and test it? I am almost certain you won't have any issues.

 

[DDW]

Lifelines are not current limited on charge. In other words, as long as you stay below the absorb limit (14.5 or so) you can connect them to an unlimited current source. In practice, at about 50% SOC they will take about 0.5C for a little while (so 50A on your 100AH battery). Even at 20% SOC it will only take 60 or 70A for a short time. If you look at a Noco 1000A jump box for example, they give the battery capacity as 24W-H, or about 2 AH. If you hook it to your 100AH battery, it will last about 2.4 minutes. That isn't long, but if your engine hasn't started by then, you have other problems. The recharge rates of the Noco box suggest that they are electrically limiting the charge rate going in.

 

[MagentaLine]

Lifelines are not current limited on charge. In other words, as long as you stay below the absorb limit (14.5 or so) you can connect them to an unlimited current source. In practice, at about 50% SOC they will take about 0.5C for a little while (so 50A on your 100AH battery). Even at 20% SOC it will only take 60 or 70A for a short time. If you look at a Noco 1000A jump box for example, they give the battery capacity as 24W-H, or about 2 AH. If you hook it to your 100AH battery, it will last about 2.4 minutes. That isn't long, but if your engine hasn't started by then, you have other problems. The recharge rates of the Noco box suggest that they are electrically limiting the charge rate going in.

Very informative. So should my bank die if I have been running the batteries in parallel, I should switch to a single battery and realize I only have about 2 minutes to hit the starter after connecting.

 

[DDW]

You are only going to want to connect for the moment that it takes to hit the starter button. If a diesel doesn't start in a few revolutions (<10 seconds), you've got a problem that needs to be addressed. No point in draining your jump box while you scratch your head.

 

[solosailor]

You could use a small NOCO 20A starting battery. Charge it from your house bank using a Victron 9A DC-DC or such.

 

[SolGato]

A coupe of general statements relating to your proposed use/setup.

First, unless your batteries are Dual Purpose Deep Cycle batteries, it is not wise to use them as a starting battery. This will shorten their lifespan as (generally speaking) Deep Cycle batteries are designed to power smaller current draw over longer periods of time versus the heavy cranking load of a starter.

Plus it sounds like there may be a scenario where your bank is already depleted from house use, and then you may want to use it as a starting battery which would be very hard on any battery.

Secondly, how old is your current battery?

I ask because it’s never a good idea to mix batteries of different ages when wiring in Series or Parallel. You mentioned you were going to add a second battery in Parallel to increase your capacity, however it is always best to buy new batteries with matching manufacture dates when creating a multi-battery bank with a common charging source.

Can you start an engine with a regular Deep Cycle battery and mix old and new batteries, sure, but in general you run a greater risk of shortening the lifespan of the bank.

Have you considered instead going with LiFePo4 for your house so you can have 2X capacity, then have a secondary LA battery as a dedicated starting battery?

 

[Zonker]

First, unless your batteries are Dual Purpose Deep Cycle batteries, it is not wise to use them as a starting battery. This will shorten their lifespan as (generally speaking) Deep Cycle batteries are designed to power smaller current draw over longer periods of time versus the heavy cranking load of a starter.

Why do people think this? For the same amount of lead:

Deep cycle batteries have fewer thick plates so they can withstand repeated deep discharges, because each time you discharge you damage the plates a tiny amount. Thicker plates last longer as they do gradually shed material. For the same amount of lead they do generate lower starting current than a starting battery.

Starting batteries have more thinner plates, because surface area is what governs how fast you can draw current out of them. The chemical reaction is taking place on the surface of the lead plates.

To suggest that you will damage a deep cycle battery by asking for a few hundred amps for 5 or 10 seconds is plain wrong.


Here's a cut and paste from Rolls brochure. Why would they brag about the cranking amps of a deep cycle battery if it would damage it? Wouldn't they say "don't use a deep cycle battery for starting your engine because it damages it"

"Our most popular marine models are based on the well recognized GC2/GC2H, Group 24, Group 27 and Group 31 sizes. These Rolls flooded deep cycle models are specifically designed for the marine environment, offering exceptional capacity, crank amps, cycle life and the highest lead content and liquid reserves of any deep cycle marine battery."


More evidence? Here's the spec sheet for a Group 24 random Rolls deep cycle battery. It specifies both an amp.hour rating and cold cranking amps. Specifying a CCA suggests its ok to start an engine with it.

S12 24 | Rolls Battery

www.rollsbattery.com

 

[MagentaLine]

A coupe of general statements relating to your proposed use/setup.

First, unless your batteries are Dual Purpose Deep Cycle batteries, it is not wise to use them as a starting battery. This will shorten their lifespan as (generally speaking) Deep Cycle batteries are designed to power smaller current draw over longer periods of time versus the heavy cranking load of a starter.

Plus it sounds like there may be a scenario where your bank is already depleted from house use, and then you may want to use it as a starting battery which would be very hard on any battery.

Secondly, how old is your current battery?

I ask because it’s never a good idea to mix batteries of different ages when wiring in Series or Parallel. You mentioned you were going to add a second battery in Parallel to increase your capacity, however it is always best to buy new batteries with matching manufacture dates when creating a multi-battery bank with a common charging source.

Can you start an engine with a regular Deep Cycle battery and mix old and new batteries, sure, but in general you run a greater risk of shortening the lifespan of the bank.

Have you considered instead going with LiFePo4 for your house so you can have 2X capacity, then have a secondary LA battery as a dedicated starting battery?

"Deep cycle" batteries, as I have used the term here, are not, as I believe, true deep cycle batteries like the 6V golf cart style batteries I mentioned in my original post. The last couple of boats I had, I've used these "not really" deep cycle batteries for house and start purposes including lead acid and AGM.

My new to me boat, a J/100 has just enough space for two group 27 batteries, only one of which is currently installed and I don't know the age or condition. In the past, I've used a chinesium 50w solar panel lashed to the bow and connected to a victron controller to keep things topped off when at my mooring. My initial thoughts were to replace the single group 27 battery with a 100Ah Li battery which could be drained to almost zero charge rather than two AGMs with a 50% drain limit, and put a dedicated starting battery in the other space. However, as one cannot use the Li to start the engine, (the battery would shut down with any large current draw), this would require:

1. Replacing the 1/2/Both switch with a dual throw switch
2. Rewiring the alternator to the Li house bank.
3. Installing a battery combiner with appropriate fuses and start isolator connection.

Accessing the alternator and starter wiring is almost impossible without dismantling a glued or glassed in bulkhead or maybe taking out the alternator itself. (Curse these damn builders).

So to avoid the extra hassle, I was simply going to put in two new 100Ah AGMs in parallel and should I ever run out of enough juice to start the motor, I would use the Noco, hence this thread. I'm still wary of how this would work in an actuality, so I'm thinking I might just add a third battery... a smaller motorcycle start battery... mount it to a bulkhead under a cockpit locker and add a simple Yandina combiner to keep it topped off from the house battery.

As I said, this system will be topped off with the solar that I take on and off at the mooring. The only electrical requirements are the autopilot (I single hand about 95% of the time... even with spinnaker so a good below deck AP was a must for me), boat electronics, vhf, nav lights, and stereo.

 

[Zonker]

Maybe watch some folks on youtube start big motors that are hooked up to big (dead) batteries. The jump box people seem yo have this figured out already

 

[MagentaLine]

Maybe watch some folks on youtube start big motors that are hooked up to big (dead) batteries. The jump box people seem yo have this figured out already

I have seen those. But although they have engines with large displacements, it doesn’t address connecting up to a depleted large capacity battery.

I didn’t mean to start a whole pissing match here… was just hoping if anyone here had good results with using one as a backup power source on the water.

 

[Zonker]

Here is the first youtube video I found. Big diesel 6.7L pickup truck. Dual batteries.



The truck has 2 batteries. Not sure but I think they were operated with both connected. Each is a 850 CCA / 80 A.hr battery. In the video the voltage of both the batteries is 4.5V. That is (a) dead as can be (b) a reasonable A.hr capacity. He ended up using 2 jump boxes, one on each battery, but they sure didn't drain and try to recharge a virtually dead battery.



The batteries on this truck has a 0.65V pair of starting batteries. That's so extra-dead.

He mentions a slide out battery tray so I think the starting batteries are quite big.

The jumper box he uses starts at 98% capacity and by the 4th try when he gets it started is down to 72%. So clearly some power has flowed to the dead battery. But not instantly. I'm guessing there is current limiting circuits in the box to avoid depleting it's own battery

Clearly these are pretty big batteries and also very, very dead. So I think they have shown they can deal with the situation you're describing.

Maybe this would help? It alarms when it gets to about 12.0V. That's about 50% discharged. Gives you time to start the engine and charge your battery.

Low Battery Voltage Monitor 12 Volt Bank Detector Discharge Voltmeter Alarm w/ Mute #BTM10a

Monitor your battery or battery bank for a low voltage condition, Know when the battery must be charged. Stackable for multiple battery banks. Extra loud tonal alarm and indicator. #BTM10a Aluminum mounting plate. Stackable for multi battery banks. Battery life is reduced when the battery...

12vtechnology.com

 

[LiquidSun]

"Starting batteries should not be used for deep cycling, but deep cycle batteries can easily be used for most starting purposes. I use deep cycle batteries for starting on almost all sailboat installations. Why? They last longer and can be called upon for cycling if or when the house bank fails. A small aux diesel engine can be started by even a PWC battery so a decent deep cycle house bank makes easy work of motor starting."

What is a Deep Cycle Battery? - Marine How To

Light Cycle vs. Deeper Cycle NOTE: This article deals with FLOODED marine batteries, not AGM or GEL batteries. The Problem: The problem, as I see it, is one of dishonest marketing where multiple battery types wear the same clothes (sticker) and will perform differently when

marinehowto.com

"Unfortunately the industry has no real marketing definition of what “deep cycle” means so any battery a manufacturer feels they want to slap a “deep cycle” sticker on, gets one. This range of deep cycle labeled batteries spans all the way from a Group 24 12V automotive cased battery up to and including massive 15-20 year expected life 2V cells used in stationary applications. A 2V cell is obviously more “deep cycle” than even golf car, fork truck or sweeper scrubber batteries but all may wear the same deep cycle sticker. If you buy batteries more carefully, you can get more life out of them, for your dollar."

 

[LiquidSun]

Automotive Alternators vs. Deep Cycle Batteries - Marine How To

A Deep Cycle Battery Assassin The alternator pictured here helped to destroy a very expensive bank of TPPL AGM batteries in under two years. These batteries need an absorption voltage of 14.7V. The highest voltage I recorded on this vessel was 13.58V at the battery terminals. At this

marinehowto.com

 

[Quickstep192]

Speaking of NoCo jump starters…

Woot

www.woot.com

 

[Skid51]

I am facing exactly this same issue. I currently have a single group 24 deep-cycle battery on a 28’ racer/cruiser with a Yanmar 1GM10 engine. It’s working fine but am looking for peace of mind that I can always start the motor after a few days of cruising, which can include auto-pilot use. Wiring in a motorcycle battery could work but was looking at a 1000A Noco booster as cheaper (especially after wiring in the needed switches/controller for a 2nd permanent battery), even lighter (5lbs), and portable for using off-boat as well. Any better choices?

 

[solosailor]

Again, NOCO 20Ah starting battery, not a jump starter. Ithas max 25A charge rate so use a Victron 9A DC-DC to charge it. Less than $400 all in.