Battery Chargers

[smullis1961]

I have a 88 Carver aft cabin and the battery charger is a Professional Mariner 35 Amp charger 3 bank with an input of 85 to 140 V.A.C 60 cycles 3 amps. It is very old with rust. I am looking for recommendations for a replacement of it to ensure I have a newer smarter charger.
Thanks
Steve

[Cooler]

There are a few to pick from. Pro-mariner is very popular. Attwood has a couple as well as Guest. Just make sure you pick at least a 30 AMP so you have 10 amps available on each bank. Also, this is one of those items that a professional should install IMO. The battery type has to be selected as well as the connections need to be correct. Good luck! er

[km1125]

What is your battery configuration?

If you're just charging three batteries of the same configuration, then a three-bank charger is the way to go.

However, if you have a large house bank and then a couple of start batteries for the engines, it would be better to go with a two-bank dedicated to the engine start batteries (which can be a fairly small charger) and a separate dedicated charger for the house bank that is sized to appropriately recharge the house bank or run the loads on the house circuits.

Let's say you have 20A of typical loads on the house side while you're using the boat (at the dock, plugged into shore power). If you had a 30A three-bank charger to feed the house and two starting batteries, the house battery would actually be DISCHARGING the whole time, while there was a bunch of unused capacity tied to the starting batteries (because there's virtually no loads on them and you're just topping them up or replenishing what might be used from a bilge pump). That's a good example of where you might want just a 10A two-bank charger for the engine start batteries and a dedicated 30A charger for the house.

Each case can be different...just some things to consider.

[Viper]

Source of the post.... Let's say you have 20A of typical loads on the house side while you're using the boat (at the dock, plugged into shore power). If you had a 30A three-bank charger to feed the house and two starting batteries, the house battery would actually be DISCHARGING the whole time, while there was a bunch of unused capacity tied to the starting batteries (because there's virtually no loads on them and you're just topping them up or replenishing what might be used from a bilge pump)....

I'm not quite following. Most good chargers these days will throw full output to any one bank at a time when needed. With a ProNautic 30 amp charger for example, it will direct full output (30 amps) to the house bank if the engine batteries are already topped up which is pretty typical as they're usually already at full charge after a run. So very little needed from the charger at the dock for the engine batteries, maybe a float charge at best but certainly not 10 amps, at least not for very long at all. With only two banks on board, the third output leg from the charger can maintain the generator battery at peak charge. Even with that, the output to the engines and genny would be minimum, leaving plenty for the house bank. Of course more is better in terms of keeping up with consumption at the dock but power management is key no matter how big the charger is.

[Midnightsun]

I have a newer Pronautic 50a which will throw 50 a at the battery which requires it which is usually the house bank as the rest are generally full all the time just as Viper described.

See description at link. Boy have prices gone up. Paid around $350 in 2019. https://www.westmarine.com/buy/promarin ... --12039475

This very nice and powerful charger will be pretty much overkill now with the Lithium house bank going in soon as it will have a dedicated 80a charger on it. The 1250P will now do the starting batteries, the thruster batteries, the generator battery.

[km1125]

I'm not quite following. Most good chargers these days will throw full output to any one bank at a time when needed. With a ProNautic 30 amp charger for example, it will direct full output (30 amps) to the house bank if the engine batteries are already topped up which is pretty typical as they're usually already at full charge after a run. So very little needed from the charger at the dock for the engine batteries, maybe a float charge at best but certainly not 10 amps, at least not for very long at all. With only two banks on board, the third output leg from the charger can maintain the generator battery at peak charge. Even with that, the output to the engines and genny would be minimum, leaving plenty for the house bank. Of course more is better in terms of keeping up with consumption at the dock but power management is key no matter how big the charger is.

The ProNautic chargers are like many "old school" chargers in that it is essentially one charger with three diode-isolated outputs. it does not monitor the three outputs individually, nor "directs" current to any one of the three. The current is drawn by the battery needing it most. All the charger does is regulate the output voltage based on a charge profile and the batteries really do the rest. In the OP's case, it would make a good replacement for his old one. If you buy the 40A version, any one of the outputs can be utilized up to 40A, or that 40A can be split among the 3 batteries.

Those chargers are different than, say, the NOCO Genius, the Guest ChargePro or the ProMariner ProSport chargers, which are also good chargers. These have true isolated outputs instead of just a diode-isolated output. One clue is whether the charger shares a negative connection for all the batteries or if there is a dedicated one for each battery. In these chargers, each output is essentially a separate charger. If you buy a 20A two-bank charger, you get two 10A chargers in one box. There is no "sharing" of the whole 20A output... you only get a max of 10A on any given output.

I could buy a Pronautic 40A charger and it could provide 40A on any of the three or four outputs, or I could buy a 40A Guest ChargePro but I'd only get a max of 10A out of any of the individual outputs. The "kicker" on these true-isolated units is that you could also tie two or more outputs together and "double up" the amps. Say you bought the 4 bank version but only had two banks, you could tie two of the outputs to each bank giving you 20A per bank, or with three batteries you could tie one each to batteries one and two, but two outputs to the third battery. The first two banks would get a maximum of 10A, but the third battery could get up to 20A. On true-isolated chargers, each output is monitored and voltage regulated independently.

[Viper]

Source of the post

I'm not quite following. Most good chargers these days will throw full output to any one bank at a time when needed. With a ProNautic 30 amp charger for example, it will direct full output (30 amps) to the house bank if the engine batteries are already topped up which is pretty typical as they're usually already at full charge after a run. So very little needed from the charger at the dock for the engine batteries, maybe a float charge at best but certainly not 10 amps, at least not for very long at all. With only two banks on board, the third output leg from the charger can maintain the generator battery at peak charge. Even with that, the output to the engines and genny would be minimum, leaving plenty for the house bank. Of course more is better in terms of keeping up with consumption at the dock but power management is key no matter how big the charger is.

....The current is drawn by the battery needing it most. All the charger does is regulate the output voltage based on a charge profile and the batteries really do the rest.... In the OP's case, it would make a good replacement for his old one. If you buy the 40A version, any one of the outputs can be utilized up to 40A, or that 40A can be split among the 3 batteries......

Semantics I guess, we're basically saying the same thing with different English My point was about not having enough output to deal with house loads at the dock and that the bank would be "DISCHARGING." That would likely be the case with isolated outputs but not the norm with a ProNauticP for example for the reasons we both stated. Frankly the start batteries don't mean much to me for charging except when another load comes on like a pump but that's usually intermittent and if required, the engine bank can demand more if needed. I'd rather have this type than the ones that split their output evenly per bank. I use the term "evenly" loosely as they don't split the output evenly in all cases, you could have a 40A unit designed with 2 x 10A and 1 x 20A outputs.

[Viper]

BTW, I'm not a fan of a NOCO on a boat. They're not made for that IMO.

[Midnightsun]

Source of the post BTW, I'm not a fan of a NOCO on a boat. They're not made for that IMO.

Well kick me then. I do have a 4 bank (10a/bank) Noco on the boat but my reason is justified. https://www.amazon.ca/NOCO-GEN4-Waterproof-Battery-Charger/dp/B003JSLWWA/ref=asc_df_B003JSLWWA/?tag=googleshopc0c-20&linkCode=df0&hvadid=292906086628&hvpos=&hvnetw=g&hvrand=8369823561773413040&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9000604&hvtargid=pla-435717172005&psc=1

Problem with my boat is if on blocks or anywhere else for that matter you need 220v to get power on board and that means no way of charging the batteries. I installed this connected to all 4 banks in order to charge as required. I have a 110v recessed outlet beside my shore power connection which goes directly to the Noco so I can plug in to any 110v outlet and charge. Bottom line it is rarely used and never operational unless on the hard now and then.

Hmmm, need to update my photos as the picture there does not show the 110v inlet. Looks like this. https://no.co/gcp1

[bud37]

A change in kind to a pronautic or any quality marine charger will work just fine in this case IMO.......I think they are looking for simple no fuss upgrade.

Hans the noco is probably fine, it is just how they wire the grounding that may be an issue. But since you only use it for storage then have at it.....imo.