Charging dinghy from mothership

[sparrowhawk1]

Damn I should slow down and read the fine print. back to the drawing board[emoji22]

[sparrowhawk1]

How about this

[noelex 77]

Sparrowhawk I admire your determination, but using a power supply to charge a battery is not the right tool for the job. Asking for a recommendation is a bit like the guy in the picture below asking which is the best electric scooter to tow his boat .

A DC to DC battery charger is the correct approach.

[sparrowhawk1]

I think everyone's missing 2 big points. I don't want to take more than 20 to 30 amp hours out of my house Bank overnight. I do not need to top up my trolling battery with my house battery. Can the last controller I showed the specs for put two amps constant into my trolling battery through a 25 foot 12 gauge wire from my house battery?
Also I've seen several marinas that use incredibly small vehicles to move trailered boats around the marina including a geared down mini bike and hand carts. I would think electric would be far superior than Briggs & Stratton or Ape Power.

[sparrowhawk1]

Thread drift

[sparrowhawk1]

Give me a little time and I'll recommend the best scooter

[sparrowhawk1]

My point is you don't always need a pickup to move a trailer. And this scooter looks pretty cool[emoji48]

[a64pilot]

The Marina at Carrabelle Fl yrs ago used to launch and retrieve trailer boats with a golf cart, it’s surprising how much a golf cart can pull for a short distance

[john61ct]

For this specific line of questioning the RC enthusiast forums would yield much better advice. Just don't lead off with your $20 fantasy, tell them money is no object and then work downward in quality from there.

Are all your postings above about the one same model linked to in #52 ?

If so you must have missed my statement that a "buck" converter steps voltage **down** only.

See the input vs output specs?

You want one where the outputs are **higher** than the inputs.

AKA a "boost" converter.

Note in scammy marketplaces, the item titles often fraudulently contain words that do not apply to the item, for SEO optimization purposes.

Also counterfeiting abounds. Ebay's vendor rating system and NQAMB guarantee policy I think makes it more reliable than Amazon market for stuff like this.

But that's not a high bar, the other self-selling vendors I mentioned earlier would likely be better.

You have also ignored my provisos about amps capacity, especially actually measuring what's actually going on now, when you just connect directly.

That would be particularly important with a unit that handles overcurrent by dropping voltage.

Please do not interpret my helping you select a converter as implying I think any of this is a good idea.

[sparrowhawk1]

First I need more time to digest what you've told me but I want to keep this rolling, I have many projects going. I've repeatedly said I'm not looking for you to condone. Yes the first converter had a misleading headline. the second converter is different and according to the specs can do what I want. But I know that I miss things in fine print and maybe not know exactly what to look for I'm learning a lot that's why I'm asking for help. I originally asked for a recommendation because I know of the Shady practices..

[sparrowhawk1]

Once again I want to thank everyone for their help. I've got a lot of projects going on right now. all I want is a recommendation for a step up voltage converter or a reason the one I picked out won't work. (edit) the post #62 are the specs for post #70

[john61ct]

Better to avoid confusion by posting links, to enable further investigation wrt more detailed specs, other sources etc.

And I know **you** don't care about my not condoning the bigger picture.

But my concern is I don't want the potentially thousands of others viewing this in coming years via google etc to think it's a good idea, so feel free to ignore my disclaimers.

[john61ct]

Again, much too small ampacity, and poor overcurrent handling.


These converters are designed to go, if using a battery, either

**from** a steady-state power supply with controlled output way lower than that 8A, or

**into** a battery that would never accept that current level.

Going from one bank to another, with the details withheld by you after many requests, creates so many wildcards.

So, again, in cheap Chinese territory, the **lowest** rated current spec'd (in this case 8A) should be

**at least** triple the **highest* actual amps you can measure flowing in worst-case conditions.

Which last spec we have yet to see as well, really flying in the fog wearing a blindfold.

At this point, maybe best to just order a few different ones and test them out.

When you find one that appears to work, report back here, and buy a few spares.

[john61ct]

Besides the RC battery guys I recommended, the EV world has lots of sourcing geeks way more knowledgeable than most of us.

http://www.eevblog.com/2011/01/17/ee...ost-converter/

You keep saying "all I want" as if many boaters would be au fait on the topic. That is not the case.

When you get to my level, at least I've learned enough, to realize how little I know.

Those starting out think everything should just be easy.

cf. Dunning—Kruger, universal law of learning

[john61ct]

Maybe this? Still not a high current tolerance IMO, I'd keep looking.

https://www.ebay.com/p/Boost-Voltage...4v/22011328335 Have not researched in detail, just an example of the type

Model# is 2001709014

Cheaper source, not vouching
https://www.droking.com/1500w-power-...dapter-charger

After all this work, I expect a full detailed report once you get things working. No matter how busy you are, capiche?