Battery chArger size

[MV Mystery]

My charles industries 40amp charger is starting to act up. I may need to change it, but they apparently no longer manufacture marine chargers.

Would you think a 30 amp charger or even a 20 Amp would be sufficient?
We run generators 100% of the time aboard and only use my 24v bank ( that supply house and engine start) for the vacuflush systems and a few other minor accessories. I’d like the charger to handle starting the engines from a weak bank if need be.
My setup is 2 pairs of 8D batteries per Detroit diesel supplying some house and starting of main engines.
( my 12v generator bank is separate and run other shower pumps and minor lighting etc)

I’ve never seen my charger at 20 amps on the gauge in all my years with regular usage.

 

[Cricket]

I would not cut back on the output amps, you may need it some day.

 

[Boatsb]

It's based on battery bank size.

I'd not go smaller. A simple formula is 10 hours to charge or less.

So 600 cca needs a 60 amp charger.

 

[rustybucket]

We put in the 45a Analytic systems smart charger. At the time, this was the largest capacity smart charger I could find. The thing is a beast and will hopefully lead to extended battery life.

Probably picked up 2knts on weight savings along lol.

 

[MadHatter53]

I'm planning on replacing my " lamarsh" charger this coming season. It works fine but it is OE and want to upgrade to new tech for my old 32V system. I haven't found many 32v chargers with good or any ratings. I saw the analytics systems and it seems tiny compared to what I have. Not trying to hijack the thread I didn't want to start another about chargers etc.

 

[rustybucket]

I'm planning on replacing my " lamarsh" charger this coming season. It works fine but it is OE and want to upgrade to new tech for my old 32V system. I haven't found many 32v chargers with good or any ratings. I saw the analytics systems and it seems tiny compared to what I have. Not trying to hijack the thread I didn't want to start another about chargers etc.

When comparing chargers be sure to compare amps apples to amps apples, the analytics charger is rated for 45amps continuous (going off memory here on the number so don't quote me). Many of the other chargers stated higher amp rates but not rated for continuous use. If you dug and found their continuous rating it was far lower than the analytic.

 

[Pascal]

An 8D is 225 AH if I m not mistaken, so 450 for both... you re never going to go below 50% so 30amp charge will get you charged up in 8 hours. I wouldn’t go less than 30 though. Especially nowadays with most lights being LEDs demand on chargers have gone down significantly. Even more in larger boats with 120v refriferation

 

[Boatsb]

2 pairs of 8D batteries at 24 volts?

Smallest I'd consider is a 24 volt 30 amp charger BUT keep in mind the battery type and smart charging.

Look at the Victron IP44

https://www.victronenergy.com/chargers/skylla-ip44

The 24 volt 3 output charger is great. Just max 30 amps. Id like to see higher amps

Or the Skylla versions https://www.victronenergy.com/chargers/skylla-i

24 volt and 80 amps.

 

[Jammin']

Are any of these chargers capable of [FONT=Arial, sans-serif]multi-program multi-output with independent temperature compensation on each bank?[/FONT]

 

[Boatsb]

I dont think so. I've used the 1+1 for independent battery banks. And the 3x for 2 start and a generator in the ip44 model. Never had 2 or 3 separate types of batteries on the 3 banks myself.

 

[Reefgeorge]

Almost all chargers are "multi" output but many of them are just 2 or three connection posts with those outputs all on the same single charging channel/algorithm and just isolated with a diode. Every battery/bank gets the charger needs of the most depleted battery/bank. This can lead to over charging of a seldom used battery. I actually went to seperate chargers years ago even though you can find them with completely seperate channels but with my set up, if a charger goes down I can still keep going and take the bad one offline for repair. It has saved me once in a pinch.

George

 

[Jammin']

When I look at the charging specs for different types of batteries, flooded, AGM and gel, it seems the differences in charging voltages to compensate for battery temperature dwarfs the differences in charging based on the type of the battery.

 

[Reefgeorge]

Temp probes on the battery bank to vary charging voltage increases battery life and in a good charger signal the unit to shut down if something goes wrong like a shorted cell.

George

 

[madhatter1]

The Hatteras 12/24 battery set up works with a 2 bank high amp 12V charger for house and gen batteries (one port, one SBD) and 2 more 12V low amp single bank chargers for the second battery on each 24V group for engine start. The Alternator is (I believe) 24V and charges both batteries at the same time. The only time the batteries are not single 12V batteries is during engine start and alternator charging.

all that said single multi bank chargers cannot be used. The reason is they only have say 3 12V outputs with a common negative. This would cause a short between 2 12V batteries. The way 12/24V is obtained is the location of the taps on each group.

Easy way to explain that is on my 36V golf cart I get 12V for radio and crap (yes, I pimped my ride!) by going to the positive on any battery and the negative on the next one after it.

 

[MV Mystery]

Thanks for all of your input. The internal fan is bad on my chArles unit. I ordered a new fan but looking down the road I will have to get a new charger. I agree that with all of the LED lighting etc. charger capacity specified in the 80’s is probably an overkill now.

 

[Pascal]

We have 3 Charles chargers on the 84 Lazzara i run

Since they re 10 years old, I decided to get a new main 24v charger as a spare in case the CHarles fails while in the Exumas since we spend a lot of time there. CHarles being out of the marine charger business, I got a 220v Victron Centaur 24v 60amp. For now it’s staying in its box so no feed back. Paid $900 from Ward Electrics in FTL

 

[Cricket]

I've noticed a lot of the new high end boats are using Dolphin chargers or the Victrons.
Dolphin made the electronic Sentry chargers for a long time, our electronic 24v electronic Sentry charger is 17 yrs old, have replaced only the fan twice in all that time.
Did had 2 x 12v electronic Sentry's go bad over 14 years, through in a ProMariner Pronautic, because we needed a charger right away 3 years ago and it's been perfect.

Btw, have a spare 24v Sentry charger new in the box stored under the bed for when the current 24v goes bad.

 

[Pascal]

Not a big fan of Dolphin. I had one crap out on a 70 footer I used to run at about 8 years old and the replacement lasted 3 years. I went with a Charles after that

I put two Promariners ProNautics on my boat. A 24/30 for the house bank and a 12/30 for the two mains and gen batteries. They re pretty compact so I mounted them under the helm, in the companionway above the forward ER doors. Out of heat and the panels can easily be read. Excuse the dust and visible wires in the pic

 

[Boatsb]

Basic battery care. A 12 volt bank is easiest. a 24 volt bank can be better served with a battery equalizer added.

https://www.victronenergy.com/battery-monitors/battery-balancer

Id recommend the following if you wanty to be covering the bases

2 battery balancers ( 1 for each pair of batteries ) $50.00 each

Charger I like best at 30 amps
Skylla IP44 24/30 (3) 90-265VAC can do both banks $699.00

Larger if you want a more basic but more amps

Centaur Charger 24/60 (3) also can do both banks but analog controlled. $750.00

PM Me if you need assistance

 

[bigbill]

Not a big fan of Dolphin. I had one crap out on a 70 footer I used to run at about 8 years old and the replacement lasted 3 years. I went with a Charles after that

I put two Promariners ProNautics on my boat. A 24/30 for the house bank and a 12/30 for the two mains and gen batteries. They re pretty compact so I mounted them under the helm, in the companionway above the forward ER doors. Out of heat and the panels can easily be read. Excuse the dust and visible wires in the pic

do you hit them when going down the steps to the rear? seems like they would be in the way