Got stranded last time out due to electronics running the cranking battery down. Would not jump from either trolling motor batteries or another boat.
Just wondered if anyone has actually used one of these type chargers and if they actually work on the bigger engines 250 and bigger

I recently had a battery go down in my vehicle, the car would only click. A passerby had one and it started the car right up. It would not be a bad thing to have on board, they are small and they are not very expensive.

I have one and used it on my boat Motor home and my desiel truck. Work like a champ.
Johnny

They work very well. Get a decent brand and keep it charged so your cranking troubles will be over.

Check out the junojumper, by junopower. This thing is about the size of your cell phone. I have jumped my 200 Yamaha and small cars with it. Great for having on the boat to charge cell phones etc too.

A clarification for you: The jumpstarters are NOT chargers for big batteries like they can be for a cellphone. It is unwise to leave them connected to a heavy load for very long. Instructions for jumpstart use say to limit the amount of time connected and remove immediately after starting. The Li-ion cells can provide an extremely high surge of current - but not for very long before they heat up - a lot. When the engine asks for power, it gives it in a big way at very high current rates - then you need to disconnect right away so the unit can cool down.

Yes, they will work. I have one, and it has never failed to start anything I've tackled with it. However, I have a model that is rated to start diesel engines (such as in a pick-up). You are much better off spending some extra $ from the get-go and get one with power to spare just to be sure. There are a lot of this type product offered with mystery-branding on ebay and elsewhere at cut-rate prices. Please don't go that route. The li-ion cells in that junk can be dangerous, just like the ones in so many hoverboards that have caused many fires. (I have enough knowledge in the field to know what scares me...)

The most reliable one I found is from a company who has been successfully dealing with cells such as these for years. Their top model was selected by Consumer Reports. This is the only product of this type I trust. It comes as a small zip up kit with many different attachment connectors/cables for everything from vehicles to computers and cell phones. The built-in flashlight is extremely bright, has built in strobe and SOS functions suitable for on-water emergency use after dark. Mine is almost always in the truck, but gets moved to the boat as part of my launch process. I never intend to be without one.

Mirostart XP-10 jumpstarter by Antigravity Batteries

In Stock
$119.99


NOCO GENIUS GB40 BOOST+ JUMP STARTER - 1000A
GB40

Genius GB40 Boost+ Jump Starter - 1000A

GB40 NOCO Genius Boost Plus 1000A Jump Starter - Car & Truck. BOOST+ (Plus) is designed for standard vehicle applications such as cars, trucks, SUVs, motorcycles, ATVs, UTVs, lawn & garden, and more. It is powerful enough to start diesel engines that require more power. Nearly twice the power of the original GB30, there are very few applications BOOST+ won't start, even in extreme cold.

The One. The Only. The Genius BOOST Series Jump Starters are the only Jump Starters on the market with Patented Safety Technology.

Designed. Prototyped. Tested. - NOCO tested prototypes of various designs on hundreds of vehicles and applications. The result is a precision battery clamp capable of securely attaching to virtually any battery terminal. In addition, the removable eyelets can be permanently mounted to applications, like motorcycles, where the battery is hard to access directly.

Features:
For Cars and Trucks
For engines up to 6.0L/3.0L Diesel
Lithium 1000A
For 12V Lead Acid Batteries
Actual Power Output: 7000 Joules
2XLED
Precision Clamps For A Tight Fit
Full Size Use
Easy Storage
Designed, Prototyped and Tested
Safely jump start a dead battery in seconds
Up to 20 Jump Starts per charge
Ultra Safe Spark-Proof Technology
Reverse Polarity Protection
LED Light Ultra-Bright with 7 Modes including SOS and Emergency Strobe
USB Power - Recharge Virtually any USB Device (including Smartphones & Tablets)


In the Box:
GB40
HD Clamps
USB Cable
12 Volt USB Charger
Drawstring Bag
User Guide & Warranty

Weego is the way to go small and works great.

We also carry the Weego Packs

In Stock

Weego Jump Starter Battery Pack+ Professional - 18,000mAh - 12V
$179.00

Weego Jump Starter Battery Pack+ Heavy Duty - 12,000mAh - 12V
$139.00

Weego Jump Starter Battery Pack+ Standard - 6,000mAh - 12V
$99.00

My 200 HP Opti calls for a 1000 CCA start battery. Recommend checking your eng. owners manual and get a start pack that will meet your motor size start requirement.

Yes, they do call for that, I agree. However, they do so for having power with overhead under all worse-case conditions. There is no way any 200/250 outboard pulls 1000 amps. If they really did, the battery leads in the outboard's electrical harness would need to be roughly twice the diameter they are. A jumpcharger that can start a Duramax diesel is not going to be unable to start an outboard on a bass boat.

The Weego units mentioned above are shown with mAh specifications. It just so happens that whatever mAh of energy can be stored in a battery has no direct correlation with how many AMPS can be delivered in a surge. The mAh spec is all about running an electronic device at a low amperage load or charging a phone, for instance.

It's almost comical that one product is touted as "18,000 mAh". Well, whoop-de-do, that's a full 18 Amp-hours! Who can tell me if an 18 Ah battery can start a V6 outboard? I wouldn't know, but it doesn't seem so impressive when stated as 18 Ah. [Example: many batteries for deer feeders are 8-12 Ah.] Since the discussion is about starting outboards, how about an AMP rating, which is vastly different than an amp-hr rating?

I have the NOCO GB40 and it will start my 200 Optimax w/o any problems.

The JS - 18 will work in Wee-Go, the JS-12 leaves a little to be desired. It will not start a deteriorated cranking battery and a V6 block.

Also Flippin-Out is right that the spike or max load amperage required does have an extreme window between various engines and we have those specs.

Does it take a "special" jump start power pack to jump start an AGM battery?