What are folks using for battery chargers

[Dennis Boyd]

Hi all, 

I read the half dozen threads on battery chargers, invertors, location, etc.      Jaywalker still have the factory orginal charger,  it's getting noisy, and I think it cooked the last set of batteries that Bill installed.   

It is now next on my refit list.     I am just wondering what brand and model chargers folks are using and having success with?   

ProMariner - ProSport or ProNautic?  Victron? NOCO? Guest?  Something I can pick up cheap at Alibaba (just kidding) ?

 Jaywalker is still traditional  3 lead acid batteries set up.   

thanks in advance for your input.

Dennis

Jaywalker

J/42 #6

[Chris]

I just installed a Victron Multiplus and am happy - but it's primarily as an inverter for me since I'm on a mooring and seldom plug in. Even though you're currently using lead-acid it wouldn't hurt to have a charger which can support LifePo4 in case you want to change later - I've made that switch and am so happy I recommend it to all who will listen. Solid state will be even better, but it's delightful to be free of the fear of partial-state-of-charge damage to lead-acid batteries! That and they soak up amps so fast that it's a piece of cake to keep them going even on a mooring with little engine running time.

[Joseph Ruzzi]

The previous owner installed a Magnum Energy ME-series inverter/charger and remote control on Spada.  The unit itself is mounted on the shelf in the port-side lazarette, while the remote control sits above the nav station desk.  I've not had any issues with it in the decade that I've had my J/40.   I've not done extended cruising, but this winter, for the first time, I used a solar panel to keep the batteries charged since I didn't have access to shore a.c. power.  

After installing the Magnum system, the P.O. left the Victran battery charger installed under the quarter berth.   Basically, it's a parallel system should the Magnum ever fail.   I've not had a need to use it.

Joe

Joe

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[Walter Caldwell]

After switching to LiFePo4 batteries I replace the original “Professional Mariner” charger with a Victron Phoenix 30amp for shore power and Victron  50 amp DC-DC for alternator charging. The shore power charger has a trickle charge for the starting battery. 

I replaced a 30 amp DC-DC with the 50 amp. If anyone wants the 30amp, I can send to you. 

Sent from my iPhone

On Jul 3, 2026, at 10:09, Dennis Boyd <dennis....@gmail.com> wrote:

Hi all, 

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[Stephen Ulman]

We just mounted a VICTRON BPC122531124 Blue Smart IP65 Charger inside the battery box under the nav station seat to charge the batteries over the winter. Two extension cables enable us to switch between the starter battery and the house bank. Victron's ubiquitous blue tooth app facilitates easy monitoring from the smartphone. The plug is a standard 15A that you might find in your house,  but a $50 adapter for shore power on a pedestal in a marina should work if needed. We have not tried this yet, however.

Hoping I'm answering the right question,

Steve Ulman
SV Finezza Veloce J/42 #20

203-727-9229

 

[Todd Stevens]

I also use the Victron Multiplus charger/inverter.  It’s really the heart of the electrical system on s/v Wild.  It would take too long to list all the things that it can do. Possibly exceeds the requirements for many who are not living aboard or extended cruising.  But it could provide the basis for future expansion.  

The main drawback is that it’s rather bulky and heavy.  The only place for it reasonably close to the battery box is the aft cabin hanging-locker. Which involves the sacrifice of closet space and introduction of some noise to the cabin.   Mainly when shore-power charging depleted batteries, but there is a little humming as the different AC loads come on and off.

I replaced the original (?) Xantrex charger/inverter which was installed way over in the sail locker. This required long runs of 12/3 and 00 cables over to the other side of the boat and back. A really poor idea.  (Can you say “voltage drop?” I thought you could.) I suppose this was to avoid sacrificing closet space and because someone thought it would be quieter out there.  I’m curious if any other boats had an installation like that? 

The Xantrex wasn’t working properly and the old AGM batteries would no longer take a charge. But after installing all the new $tuff, it turned out to all be down to bad connections in some of those long 00 cables. The lugs had never been properly crimped on!  Only the shrink-wrap was holding them together.  (!) Oh well, the old unit was a “square wave” inverter and didn’t play well with modern electronics.  It was letting all the smoke out of my TV! So it had to go anyway.  

[Chris]

Spice had an old Heart inverter charger under the nav desk, literally lag bolted to the hull (through the inner skin to the balsa!) which was still working when I replaced it last year with a Victron 1200VA Phoenix unit (screwed into some wood battens I glued to the hull after filling the holed from the previous one). That didn't last even a year surprisingly, so I decided to go with a Multiplus 2000 VA in case the shop vac I used with the Phoenix was simply over taxing it. The new unit wouldn't fit under the nav desk so I considered putting it in the aft stateroom hanging lockers as many have done - but a friend suggested that it would fit behind the nav station's upper paneling, and that's where I ended up putting it. I had to cut a hole in the bottom of that space so it could extend down, but it fits neatly now and is out of sight and out of mind, and uses the shortest possible cable runs as the batteries live under the aft end of the starboard settee. Only question I have is about heat removal, but I figure I'll vent the area before I use it extensively and that should take care of it.

So that's another possible place to put an inverter if anyone prefers it.

[douglas wilder]

Will your upgrade include new Li batteries?  Sorry if I missed in your discord.   You show several LynX connectors, which are nice but you can pare the number down by  combining the like power feeds into the system.  The use of fused output buss bars to distribute can also be used to divide the like incoming feeds from multiple solar feeds, as an example.  If going Li for the batteries and using lead for the starter batteries the positives must be kept separate, which means losing the ARC.   I use Dc/Dc trickle chargers for the two starter batteries from the house.  (Negatives on boat are still one network).   

Douglas Wilder

SV Loretta

262-844-5932

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From: j4x-owne...@googlegroups.com <j4x-owne...@googlegroups.com> on behalf of Chris <j44s...@gmail.com>
Sent: Sunday, 05 July 2026 06:52:28
To: J/4X Owner's Group <j4x-owne...@googlegroups.com>
Subject: Re: [J/4X-owners] What are folks using for battery chargers

 

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[Dennis Boyd]

Guys,   Thanks for all the feedback.   This clearly is a great topic and many different directions, available depending on one's use case.   One thing about Jaywalker is that it is still pretty stock.   And Iike Bill, I am inclined to keep it simple.   So here is what  I am learning.    Batteries are basic Pb acid, group 27's,  starter is maintenance free, without caps and is angled under helm's seat.        I believe the stock 30year old Promatic 30-3 was set up with a two battery house bank, connected as one output, and a solo starting battery set up on the other output.    So two banks, being charged with the same old school profile.   Which is think is pretty harse on the batteries (all three got cooked last summer when I was shopping for boat.) 

I could replace this with a Victron Centaur, and wire the same.  Easy, old school solution, the internet says it's bulletproof.   But, in researching, reading your suggestions,  i am now thinking i could use "smart" or "adaptive" charger.   and right now I am in the two box tribe (so I currently do not want combined charger/invertor today).     I see that ProMatic, has  product called ProNautic, which looks like it would be a direct swap out.    But you all have suggested Victron multi plus and / or Phoenix.    After reading tech sheets,  I think the Phoenix is correct  set up for my simple application.    So,  now I am wondering which version?   One has three banks output, (the sales flyer suggest, house, starter and bow thurster) other has one bank for house and then a  trickle charge for starter battery.     So does charging the starting battery with trickle charge only work?

I don't really understand the  "Victron  50 amp DC-DC for alternator charging"    Is that to charge starter battery when on the hook?  I guess I still need to understand how the alternator and engine charge (I have to fess up,  i never really given this much thought with earlier boats).     I do have a box, call a "Batt Maxx" and I have really no clue what it does, or even if it still works.  

So three questions.    I am continuing to learn. 

thanks, 

Dennis

[Todd Stevens]

The DC/DC charger, as others alluded to, is mainly for charging two banks of different chemistries.  Instead of a “dumb” automatic charge relay, or manual switch.  The alternator charges one bank (usually the start battery) and the DCDC gadget smart-charges the other bank.  Not something you should worry about with an all lead-acid setup.  But most of the ones I’ve looked at have relatively low output and kind of negate the benefits of having a high-output alternator.  

Re: the diagram that I posted. Was mostly to show possible build-out complexity and not necessarily details.  In fact the start battery loop is currently legacy stuff that was never wired correctly to start with and is disconnected. The old ACR is toast.  I haven’t yet decided which way to go with that. 

Re: the Lynx busbar system.  Wiring everything directly to a main busbar solved some problems with solar and wind charging. I.e. when charging current was high, small resistance in the multiple busbar system caused the voltage at the charging busbar to rise slightly relative to the batteries and the “smart” chargers would shut down too early.  I also didn’t like the way the high-amp loads were all daisy-chained together on a single cable.  Although I kind of wish I had just bought some bar stock and rolled my own for a lot less money.  When you buy that many blue boxes, you discover that Victron actually has a pretty high defect rate, and no real warranty or customer service at all.  And all the inter-lynx connections seem like potential trouble spots down the road if corrosion should build up.  

But they look pretty cool. And it made a huge improvement to the daily charge cycle. Even in the winter (at 26°N) running the fridge, freezer, radios, instruments, and Starlink all night, batteries are fully charged by the afternoon and the Multiplus shunts excess power to the water heater through the AC2 output. By dinner time there is enough hot water for showers and washing dishes.  Previously that only happened in mid-summer. I used to have to run the generator (or the engine) for an hour or so in the evening to top off, but hardly touched it this year.  

Sent from my iPad

On Jul 5, 2026, at 08:43, Dennis Boyd <dennis....@gmail.com> wrote:

Guys,   Thanks for all the feedback.   This clearly is a great topic and many different directions, available depending on one's use case.   One thing about Jaywalker is that it is still pretty stock.   And Iike Bill, I am inclined to keep it simple.   So here is what  I am learning.    Batteries are basic Pb acid, group 27's,  starter is maintenance free, without caps and is angled under helm's seat.        I believe the stock 30year old Promatic 30-3 was set up with a two battery house bank, connected as one output, and a solo starting battery set up on the other output.    So two banks, being charged with the same old school profile.   Which is think is pretty harse on the batteries (all three got cooked last summer when I was shopping for boat.) 

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/9021b139-6c5b-47a6-a8e0-2ac59c91e814n%40googlegroups.com.

[Dick York]

Todd-

You really stunned me....

"by the afternoon and the Multiplus shunts excess power to the water heater through the AC2 output."  Spectacular!!!  

Wish I could do that, although at 41 North, the sun angles are wrong...

Thank You for the Lessons... Dick

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