Battery testing with new load test meter.

[dsolo]

Spent the day on the boat. Physically checked the AC wiring and breaker to charger. Get this, wiring is 12 ga stranded, breaker is 10 amp. Carver most likely standardized the wiring with all appliances? Unfortunately they didn't do the the same with breakers. Changing the breaker would not be difficult. Then I looked into the panel containing the Battery switch and breakers under the step in salon. That is another story. In order to go to the 12/50 charger the all the 8 ga currently in the charging circuit would require a gauge increase to 6 ga. Guys, I'm not up to the task. My ambition has met it's limited, maybe it's the six batteries I carried up the ladder and into the engine room? Maybe it's too many projects one after the other? I am burnt out and need some boating, socializing, and brewskis.
Here is what I have decided. Monday I will contact Hodges Marine and request a RMA to return the ProNautic 1230. I will then order the ProNautic 1240. This gets me 30% more charging amps and does not require changing the 8 ga. AC feed requires no updates.

All new batteries are in place, new wood platforms worked great. Battery cables for the series parallel house bank worked perfect. Run the wire for the optional remote control, mounted remote in salon. Will have to expedite the 1240 charger, marina needs my boat out this week.

Good night, Dan

[Viper]

Source of the post...wiring is 12 ga stranded, breaker is 10 amp.....

You'd still need to replace the AC breaker for the 40A unit.

Source of the post....I will then order the ProNautic 1240.....does not require changing the 8 ga....

So you've measured the length of each charge leg both positive and negative, and each circuit is no longer than 14 feet correct? I believe at 15' you need to go with 6 AWG.

[km1125]

So, here's the thing. You have three issues to consider:
1) What is necessary to insure safety
2) What is the best for the batteries and convenience (charge time)
3) What will work, without compromising on safety.

Currently, your wires (both AC and DC) are fine and perfectly safe for the loads presented by the 50A version. The 8GA wires will present slightly more voltage drop than if you swapped them for 6GA, but they're still OK to handle even the whole 50A. It is realistic though, that not one of the individual wires will ever see that whole 50A, so your voltage drop will be even less. Voltage drop will really only be present in the bulk charge state, when the most current is going to be delivered. With slightly more voltage drop, this phase will take slightly longer but it will complete. Once the battery gets into float, there will be virtually no voltage drop (because there is virtually no current) and the battery will be fully charged.

On the AC input: The unit can consume 770 watts, which is under 7 Amps. That would be absolutely fine for a 10A breaker. There might be some nuisance tripping if there is somehow a surge, like when you first plug in shorepower but that's usually on cheaper units.

Now, here's the real key! That unit (1250P) has a feature called "Selectable Power Level". You can set it to a lower capability in case you were sharing a 15A circuit with some other loads, like galley loads. You can set this for 100, 75, 50, 25% output, which lowers the max out from 50A to 37.5, to 25 or 12.5. You could set it for 75% or 50% and it would 'emulate' something closer to the 30A that you're thinking you might need for the interim. That would also probably address any type of 'nuisance' tripping if there were any.

Contact Pronautic. Those guys are good to deal with. Tell them you really want the 50A and if there really would be any issues if you delayed changing the breaker and battery leads till next off-season.

[bud37]

Dan ,I hear ya ! Its easy to get overwhelmed by this stuff ( i feel much the same ) but never fear you will get to the end and have a very nicely thought out vessel at the end of it, then boredom will set in with no jobs to do Up and down ladders with those heavy batteries is killer, but remember "one man,one job,one day" and you will enjoy the beer better......good luck with it Dan.......

[dsolo]

Thanks everyone! I welcome and value your input and encouragement.
Viper asked if I had measured dc output conductors. Yes, fortunately the charger was installed directly below the battery switch. There might be 4 feet of conductor, that is also for the ground. I am very safe for the ProNauticP 1240 @ 8 ga. I don't think I should chance it with the 1250. I plan on using the Equalization feature of the ProNauticP. It uses high voltage to clean Battery plates. It pushes a lot of energy to the batteries, they want you to insure batteries are topped off with water prior to starting the process. I can't find where actual voltage or ampage is published? I will take km1125 advice and talk to Promarine's tech support.

I won't change the subject here, but I have a whole lot of questions regarding my new electronics. This would include isolated 12 vdc. Hope I am not taking advantage of your expertise?

[km1125]

Source of the post I am very safe for the ProNauticP 1240 @ 8 ga. I don't think I should chance it with the 1250.

It's not really a question of "safe", but just voltage drop. 8ga wires are rated for 80A, so even with derating, you'd be OK at less than 50. Also, if you use the "Power Level Adjustment", then you can set the max current all the way down to 12.5A.

Source of the postI plan on using the Equalization feature of the ProNauticP. It uses high voltage to clean Battery plates. It pushes a lot of energy to the batteries, they want you to insure batteries are topped off with water prior to starting the process. I can't find where actual voltage or ampage is published?

The voltage for Equalization is going to be 15.5 volts, and is shown in the "Setup and Operation" part of the book. The current is going to depend on the batteries. Make sure you check your battery manufacturers recommendations on if/when you should equalize the batteries.

[Viper]

dsolo, I don't want to put you through a tug of war here. I'll just say the following, then suggest you contact the manufacturer. In the end, the final decision is one you must feel completely comfortable with.

I took a look, and this is out of the manual. According to the manufacturer, the only thing you don't have to change is the 120V wiring since you confirmed you have 12 AWG but you need to replace the AC breaker and DC charge wiring:

"Charger Model........110-120 volt breaker.......AC conductor size"
"ProNautic1250P*...........15 Amp......................14 AWG"

For charge wire size:
"12 Volt 50 Amp
Wire length....10’
AWG............ 6..."

"CAUTION: If you are replacing an existing battery charger....Do not use existing cables if they are not in compliance with the sizes detailed in this manual....."

The sizing is not only for safety but to minimize voltage drop for accurate monitoring so the proper cycle voltages can be delivered without overcharging because of a voltage drop. If we want to talk standards, for a 50 amp circuit, the scale starts at 6 AWG at 0 feet, and that's under optimal conditions, not taking heat, bundles, (derating) etc. into consideration. Since your circuit is only 4 feet, you may get away with 8ga but I'd check with the manufacturer first as they don't note anything less than 10', and if they say okay, then get it in writing in case something goes wrong later.

Going against the manufacturer's installation recommendations is not a good practice. We can quote wire specs but we didn't engineer the charger and aren't privy to all the reasons for their recommendations. I've installed many of these and have never had to worry about the install coming back to haunt me because it was contrary to the manufacturer's instructions. Can you get away with it? You might be able to buy yourself some time but I'd err on the side of caution, the amount of time you have in an improper installation is just around the corner until the next perfect storm that will affect that system. Realistically, under normal circumstances, will a charge leg need to handle full output? Probably not but you can't only assume "normal" operation and must consider everything that might go wrong. This is a huge part of why the manufacturer's installation requirements are what they are.

My experience with putting off correcting the balance of an installation is that it never gets done. I see it all the time. The mentality is usually that it's been working okay so why bother. Temporary fixes rarely get remedied later. Do that with the wrong system, and it's a ticking time bomb IMO.

Which ever unit you decide to go with, do it right the first time based on the manufacturer so you can rest easy and move on.

[km1125]

Since you are replacing the charger (one way or another)... did you give a thought about having TWO chargers?

The needs are completely different for starting batteries than the house battery. You could have a dual-output small (say, 10A) charger to maintain these batteries, but have a dedicated (50+A) charger for the house.

Pros? Cons?

[dsolo]

km1125,
I thought about keeping the 30 amp charger for that purpose. But I am not sure it can handle having outputs vacant? The 20 yr old Promarine unit is a 3 circuit output unit. I used my battery tester and it's output was 13.7 volts. I believe it's functional. I know the ProNauticP is capable of managing the single leg circuit. It would apply all resources to the single load. Which brings up the DC conductor efficiency of 8 gauge. That includes the 1240 which I am leaning towards.

I plan on discussing things with Promarine tomorrow.

[dsolo]

Had communications with Promarine's tech support. Their recommendation was to change out the 8 ga conductor to 6 ga if I install the 1240. I informed him the DC run was 4 feet. He said regardless of the length he was recommending no less than 6 ga with the 40 amp charger. We discussed the 30 amp charger and my house batteries. He wanted to know what cranking batteries and generator was in the system. He stated with the right circuitry the 2 group 31 batteries should be maintained by the alternator charge. If the 30 amp charger's only demand was house it could work. We discussed my boating routine and dc loads. I left the meeting with staying with the Pronautic 1230. The work and costs upgrading to 6 ga or 4 ga may be occurred down the road? At the moment I will see how things work at 30 amps.