Charging 24 volt bank for bowthruster (or windlass)

[tgrimmett]

Hi: I am interested in other's recommendations on how they charge their 24 volt battery bank that is used for a bowthruster (or a windlass for that matter). The rest of my boat is 12v. What do you use to convert to 24v and how do you control the charge current to the 24v bank to make sure it is topped up appropriately. My charging sources are the engine alternator and a large solar array, and I'd ideally like to be able to charge the bowthruster bank from either, whichever has amps. Right now, I have a 12v to 24v converter/controller made by Sleipner/Marinco, but I'm not confident it is doing the job right.

[markcouz]

Look for a product called MPT-7210, it is a boost MPPT charger from China that I bought on Wish android app.

It is designed to accept low V input from solar panel and then boost voltage to charge battery bank at higher voltage than panels (10 amp charge rate)

You can use your 12v battery bank as input source to charge your 24v bank.

[Dockhead]

More expensive, but better, is a device built for the purpose and built for marine use, like one of the Sterling Battery-To-Battery chargers:


https://sterling-power.com/collectio...ttery-chargers

[Wood]

Or Yandina combiner. Charge at 12v then combine for 24v when needed.


Trollbridge2400 Information

[john61ct]

Originally Posted by markcouz

Look for a product called MPT-7210, it is a boost MPPT charger from China that I bought on Wish android app.

It is designed to accept low V input from solar panel and then boost voltage to charge battery bank at higher voltage than panels (10 amp charge rate)

You can use your 12v battery bank as input source to charge your 24v bank.

Kludgey workaround but yes cheap.

Sterling BB much better, but of course pricier.

The Yandina solution works great, may also seem a bit of a Rube Goldberg kludge, but allows two batteries to be charged at 12V then change to series to be discharged at 24V.

[JOHNMARDALL]

Check out the BOWPRO boosted thrusters from Vetus. They include sophisticated electronics that take a 12 volt charging source and convert it to 24 volts for battery charging. The thrusters use 24 volts in an AC induction motor (cool runnings, proportional control and long run time) and the 24 volt battery bank gets charged whether or not the thruster is in operation.

All the best
John Mardall
Vetus Maxwell Boat Equipment

[alex49]

HI,
I have same arrangement on my boat, 24v bow thruster on a 12v boat.
I use for more than 6 years the Sterling 12 to 24 battery to battery charger
and it works perfect. It is clear enough and well explained to go DIY and so I did. It is an important item,it is unique because you want to protect the source battery and the Sterling does it very tricky.I would pay the difference and go BRITISH rather than Chinese. You can really spare some money doing it yourself and 24v wiring is easy and low cost to do .

[smac999]

The mppt is a bad idea. It will constantly drain the house. You want a device that will only charge the bow if the house is charging. Something voltage trigged.

The troll bridge I would Not use for that. It allows the 2nd battery to charge from the first. But you still need a way to get power from the house to the first battery. I would not simply parellel those. So you still need a 12v to 12v dc charger. And then The troll bridge would charge the 2nd battery.


Get a 12v to 24v dc to dc charger. That is voltage triggered.

What makes you think your existing one is not working?

[john61ct]

Actually Trollbridge allows both batteries to charge together in parallel at 12V, long as not in use.

If the 24V discharge is in use, then only one battery continues charging, then they rebalance once paralleled again.

Since thrusters aren't in use for long periods, should be just fine.

Can contact Yandina's founder Ann-Marie Foster, also inventor of the first combiner/VSR/ACR!

tech@yandina.com

But I agree the Sterling is a more straightforward solution.

[SeaRaider]

Look at this:
https://www.remybattery.com/pro-char...y-charger.html
I have two 12v batteries in series for my 24v bowthruster. This charger charges each 12v battery independently. You will like it.

[tgrimmett]

Originally Posted by smac999

The mppt is a bad idea. It will constantly drain the house. You want a device that will only charge the bow if the house is charging. Something voltage trigged.

The troll bridge I would Not use for that. It allows the 2nd battery to charge from the first. But you still need a way to get power from the house to the first battery. I would not simply parellel those. So you still need a 12v to 12v dc charger. And then The troll bridge would charge the 2nd battery.


Get a 12v to 24v dc to dc charger. That is voltage triggered.

What makes you think your existing one is not working?

Thanks smac999. The existing one is giving me error messages like it is not charging, or had too much voltage source neither make sense. I'll probably return it.

[TNRivers]

Have both a second 24 volt charger for shore power and a solar panel to a Blue Sky 24 vlt MPPT controller for when anchored. 1

[john61ct]

Originally Posted by SeaRaider

Look at this:
https://www.remybattery.com/pro-char...y-charger.html
I have two 12v batteries in series for my 24v bowthruster. This charger charges each 12v battery independently. You will like it.

Maybe not what you meant, but just to clarify for others not aware:

The serial connection between the two 12V batteries to create a 24V bank must be disconnected when charging each at 12V

Unless the two sources are fully **isolated** electrically from their primary side, as well as each other. If they are, then concurrent charging via the "midpoint tap" is safe, but this is pretty rare in low-end gear.

Since this charger is advertised as 12/24V, I assume that is switched internally, varying the voltage at the output leads, so would be attached at the usual outermost +/- posts of the 24V bank, rather than using the above midpoint tap configuration.

And of course this charger requires AC input, does not help converting alternator or solar inputs.

Some people go from DC to AC with an inverter, using that to power an AC to DC charger like this, but that's a bit too redneck for me.