New Battery Bank, now how to charge them!

[bud37]

The 50 amp charger is 50 amps at the 12volt. side.......check the spec for the fusing / breaker needs, considerably less, just can't remember.....would need the wattage draw to do the math.....nothing dumb just a learning curve.....just follow their install recommendations and you will be fine.......sorry can't answer about the solar stuff.....Good luck man....

[g36]

The manual says it's 15amp ac for the 1250. If you look into leds for lighting that will help alot on your battery bank . 12vdc fridge draws around 4-6 dc amps when running. Are you using a inverter for tv? Or 12v tv? Either way this wont be a huge draw on the house bank either. If you get full sun your solar would help also. If you haven't purchased yet you could see how it goes then make your decision then on the panels.not sure where you boat but in tenneesee by afternoon or so I am running genset to run some ac to cool the boat off in evening so most of my tv etc and battery charging is happening then so if you are going to be doing similiar I dont know if i would worry about the solar

[Viper]

You can use the current 15 amp AC breaker.

[km1125]

For a 50A DC charger, you'd only use about 10A on AC. 50A*14.8V(max)= 740 watts. Divide by 0.8 to account for efficiency (~80%) = 925 watts in. 925/100 (assume lowest reasonable voltage is 100VAC) = 9.25A on the AC side.

Not sure what that "Amperage at 100 < 10.0" means unless it was supposed to say "Amperage at 100% output is less than 10 amps"... that would make sense.

The A.C. wire going into the charger can be 12 or 14 ga if it's fed by a 15A breaker.


200w of solar power will help defray your charging needs, or make it quicker to recharge the batteries. In full sun, you'd get about 15A of current but that's only going to last the few hours of peak sun...maybe 4 hours at max.

[paboater76]

You guys are awesome! thanks so much. I have a game plan, now to execute! Should be an easy swap, I have 10/3 coming from my panel on a 15amp breaker to my current charger.

I have not ordered the solar gear yet, going to get this charger project done and see how I use the new bank during normal day.

Thanks again!

[Hugo]

Check out Charles C chargers and get a Victron Battery monitor.

I have a 400 AH bank (not trojan) and use a 60 amp Charles C charger for almost ten years. With this setup I can go a few days on the hook running the fridge and all (about 100-120AH/day used) with only running the generator an hour in the morning and an hour at night before I start to approach 50% of discharge at which point I would need to run the generator for many hours. By then I run out of water anyway so it's time to go to a marina overnight and the batteries are all good to go again in the morning.

I have a 15 amp AC breaker for this charger...

Like others have said it'll take a long time to put the bank back up to 100% and even with a 60 amp charger you will not be putting 120 amps back in in two hours, it's probably closer to 70-80 amps.

The purpose of the 14.8V is to get the sulfation off the plates by raising the electrolyte temperature, you can achieve this by equalizing them at 15.5v once a year or so but that's a topic for another day as it requires monitoring temperature and the electrolyte in each cell. But if you don't get the voltage that high you'll just loose some of the capacity of the bank after a while. I've done it both ways where I have equalized and where I didn't and in the end I still had to replace the bank around the same time. What kills the batteries is discharging them below 50% so that's where a battery monitor pays dividends.

At these current levels I don't think solar will keep...

[Viper]

If your current charger doesn't have a chasis ground, you'll need to run an extra line as it's a requirement now. You'll also need to run the temp probe from the charger to one of the batteries. I recommend hooking it up to the house bank as it will typically require the highest charge. You may also want to consider the optional remote panel so you can control and monitor what the charger is doing without having to lift an engine hatch. I find it very convenient. Follow the installation instructions carefully and don't skimp on hardware quality.

[tomschauer]

PA boater, not sure if you have a wife or if she is with you when you plan to anchor overnight or longer, but I am also on the upper Chesapeake and during the summer it is rare the wife will "survive" the hot humid nights without a/c during the summer. So the genny gets to run....

[paboater76]

Thanks again,

I received my new charger, 12/50p. I'm in the process of ordering everything I need. I have a 4 position -neg ground buss bar picked out. Now I need to decide on a fuse for each bank.

Yes, old charger did not have a chassis ground, I will need to run a new leg for this one. I'm running 6awg for my battery leads, manual says this chassis ground can be 1 size smaller at 4awg.

I also got the remote panel for the pronautic, but I'm not sure I like it, I want a monitor that I can use to check and monitor my batteries while on anchor without the gen running. I think the promariner needs AC power for the remote to work, is that correct? this is why I'm leaning on returning it and going with a Victron BMV-712 Smart Battery Monitor.

Are the 6awg inline ATO type fuses bilge approved? Ignition protected? What type of 60amp fuse should I use?

https://edsboattips.com/boat-electronic ... ato-fuses/

[bud37]

Good stuff.....go with the victron, had one ,worked great, make sure all the grounds are connected to the right place and the vic will show usage/draws properly......regarding your one size smaller, if you are running 6awg, then smaller is 7awg in that direction.....good luck man, looks like you are covering the bases.......