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Ruffneck29 · 01-20-2013, 09:27 PM

New guy here and I did some searching prior to posting this question so here goes.

We recently bought a 90 Dolphin 3400. In going through the underbelly, there was a battery charge next to the converter....didn't think much about it when we bought it. After I got it home and started making my "to-do" list....I noticed that the converter wasn't hook up at all.

So, I got into it.....the converter had been removed and a battery charger put in it's place. To make matters more ineteresting, it was not wired into the 12vdc circuitry at all. It's output only went to a 4000w inverter under the couch. Yes, only the motor would charge the house batteries. There was also a switch, next to the door, that turned the battery charger on/off.......only powered when the generator was running.

I've since ripped that battery charger out, re-installed the converter(it worked

) and made the appropriate connections for charging the batteries when the generator is on/shore power. Now, the inverter will work whenever we want it to(obviously on a switch).

Ultimately, the previous owner re-wired the circuiting so only when the generator was running...with the "converter" switch on, the battery charger would power up the inverter and supply 120vac to two "special" outlets under the couch. All this while NOT charging the house batteries. I'm hoping there is a good explanation for doing this as it is unbeknownst to me.

Thanks!

TQ60 · 01-21-2013, 12:23 AM

My guess is the converter voltage too high boiking batteries.

Very little current will do it.

PO likely not too sharp either. ..

Ruffneck29 · 01-23-2013, 06:18 PM

I was thinking that or the PO came up with some sort of "never ending" power scheme. Not too sure what he might have been thinking.

Anyone else have any ideas?

TQ60 · 01-23-2013, 06:21 PM

Who said they were thinking?

DCGarcia · 01-26-2013, 05:57 PM

Lets see, Run the generator to produce 120V AC to run a charger that produces 12V DC to run a inverter to produce 120 Volts AC.
Yep, sure makes a lot of sense, and pretty darn efficient to boot - NOT.

There is one rather odd explanation however: If the special outlet was near the bedroom, then perhaps the PO had to use a CPAP machine. Pergaps he/she ran the gen all the time while sleeping, thereby making sure the CPAP always had power. This only makes sense if the PO was paranoid.

BTW, if you happen to be running the reconnected on board converter for very longs times, keep an eye on the batteries. Those old units are not smart units - you will cooked your house batteries.
Dan

Ruffneck29 · 01-26-2013, 11:32 PM

What would be considered a long time?

I will keep an eye on it and do plan to upgrade to new converter in the near future though.

Ed-Sommers · 01-27-2013, 09:31 AM

No explanation of why it was done is necessary. It was HIS way of doing things for whatever reason, if it's not YOUR way, don't do it.

To second guess, and call him "teached", without all the facts of why he preferred it being done in that manner, makes the person making such a statement the Monger IMHO.

I do suspect that the converter may not be a three stage charger, and that the type of use is in the reasoning.

Personally, as I never, ever am hooked up to facilities, my IOTA 25 AMP 24 Volt Converter is not hooked up to the DC distribution system, but is used only as a charger when/and if desired, and only when the generator is utilized on rainy/inclement days when my 1200 watt Solqr panels need a little help. My very limited use of 12 volts is supplied by a DC to DC converter, 20 Amp max.

Ed
Whom prefers friends that "do it their way".

MattC · 01-27-2013, 11:47 AM

I run into this sort of thing a lot. It is not the strangest thing I have seen.

PO probably had two issues.
First is that he thought (unproven) that the installed converter was not doing a good job of charging the house bank.
Second was that the generator is probably out of tune and his old line-sync TV didn't get along with it.

As a 1990 build, there is a good chance that the converter is not an automatic charger (3 or more stage), but a simple 13.6V power supply. This will do, but it is not a world-class item.

When you have installed a good converter, then you can also find a small automatic transfer (unless there is one in the inverter) so those things on the dedicated line don't delay charging of the house bank.

Matt

Phobos · 01-27-2013, 01:30 PM

This is sort of related, and may explain part of your question.
A few years ago, we had an issue with the house battery going dead all the time, even when plugged into shore power.
Our converter (6300 series) has a charging side, but it isn't one of the 'smart' ones. Anyway, the charging side stopped working, and after a few attempts to repair it I failed.
I wasn't ready to buy a new converter for that reason alone, so I installed a 1.5 amp battery charger/maintainer with the 'smart' technology. Problem solved right? Not quite...
While it took care of my charging problem it created another. Whenever the unit wasn't plugged into shore power (sometimes for weeks) the house battery kept going dead. Well, the 'smart' circuit board and the little led light on the charger draw power from wherever they can find it. If not shore power, then the house battery! :/
The easiest fix was for me to install a switch on the charger to open when not plugged into shore power.
While it's not the perfect solution, it's a good solid one until I buy a newer style converter. It's in the plans, just not top priority.

LindaH · 01-27-2013, 02:44 PM

When we had solar installed on our RV, we had a 2000-watt pure sine wave inverter/charger installed. The converter, although still there, was disabled. There's no reason to have both a converter and a charger.

Ruffneck29 · 01-27-2013, 10:18 PM

Thanks to all for their replies....Phobos, your description makes somewhat sense of what the PO did. I guess I can kind of see it now. Still makes me scratch my head though. Oh well, I'm sure it made complete sense to him. To each their own!

wa8yxm · 01-28-2013, 07:31 AM

There are several makes and models of converters and of battery chargers, Alas they both cover the same spread, almost.

In converters.. Many older trailers had a Magnetk 6300 Series (Check the door on your power distribution center (Breaker/fuse box)). This was a well known battery killer as it first, was a very s*l*o*w*! battery charger (like just a few amps) but what's worse, it did not know when to quit.

On the other end we have modern 3-stage converters that can kick out up to in some cases 100 amps, all or part of which can be used to charge (Some are adjustable as to max output rate no less) They sense the current and voltage and change modes as they go. Finally switching to a "Float" mode where in theory no current flows in the battery.. They continue to monitor and will go back into one of the charge modes if needed.

Older battery chargers (Say 1970ish) are like the Magnatek, they do not know when to stop. Some have a timer, that will "Stop" them but in fact,,, The odds of that being the right time, zero percent or very close to it.

To Modern computer controlled "Smart" Chargers, These chargers follow the 3-stages same as say a Progressive Dynamics 9200.. But often once they go to float, they are "DONE" in fact they may just compley shut down and disconnect instead of going to float, Cease monitoring and of course are thus not really what you want.

Recommen dation is the PDI 9200 mentioned above.. but.. Read on.

How to pick the proper size (The last two digits)

1 Group 24, Smallest 9200 made 2 9240
1 Group 27, Samllest 2 9260
Group 29, same as 27
Group 31 1 9240 2 9280

Pair of GC2 9260 or 9280

More than one pair of GC2,, or 4 27 or larger.. Biggest 9200 made (I think that is the 80).

The math

Amp hours (20 hour rate) times 0.3 = last 2 digits..

Round down prefered but if its real close you can round up to the next model,, IE if 75 or less go 60, more than 75 80