Relocating the battery charger help

Last summer I replaced my WFCO charger for a Powermax Boondocker PM4B-75 MBA. At the same time, I replaced the single group 24 battery with (2) 6v gf (from Batteries plus) so I have 230AH which I can use 50% of that (~115AH).

However, as others on the forum have noted, I don't get as much of a "recharge" from the generator(s) as I expected (or wanted). I have 2 Champion 2000W (1600w continuous load) inverter generators with parallel kit if needed. I don't mind throwing more money at the RV and replace the charger (whether it be smart or not) IF I knew which one to get. If it's not a "smart" charger, I would need some schooling on how to operate it.

Based upon the pages and pages of reading that I've done on this forum, one of the 1st things for me to do is to move the "new" Boondocker as close to the batteries as reasonably possible.

My current setup:
- (2) 6v gf batteries on the tongue. I have room for 2 more if needed (or required) to make the Boondocker work better.
- Converter/charging is roughly 17+/- feet away from the batteries with a **** load of connections along the way.
- The battery cables that are in use are what the factory installed. I don't know wire sizing so I don't know what mine is though I gather it's way undersized.

I can:
- move the charger closer to the batteries but they'll still be 4-6 feet apart. This is because the wires need to go down through the floor and then back up to the batteries.
- Use the largest wire that will fit the Boondocker (I believe that's 2 gauge).

This is where I get lost ...
- To power the charger, can I make a 120VAC run from the original chargers location (kind of like and extension cord) so it's on the same circuit breaker in the distribution box?
- Do I add a fuse between the charger and batteries on the new 2 gauge wire? If yes, what kind/size/etc?
- I assume I need to get 12VDC power back to the distribution box. How do I do this? Can I use the existing undersized factory battery cables that are already there or do I need to go much bigger?

I really can't get the charger any closer, without putting it in a waterproof box outside. Should I see a big improvement doing this?

Thanks for any help,

33 Replies

johnm1
Explorer
Mar 26, 2017
Yes, solar. I'm working with a company that's going to spec out a system for me. I live and camp in NYS so I'm not expecting a solar system to completely recharge my battery bank. More hopeful it will top it up and help a bit.
Thanksfor everyone's help
red31
Explorer
Mar 26, 2017
BFL13 wrote:

Solar is just a method to extend the time between generator recharges.

and makes a great maintainer.
johnm1
Explorer
Mar 25, 2017
epfd217 - I'm not sure I understand your comment.

I plan to use the charger to recharge the battery bank as fast as possible and do a complete and full charge when we get home.

BFL13 - I love this comment - "Each Rver is over 21 and must make his own choices"
BFL13
Explorer II
Mar 25, 2017
I prefer a two- hour recharge 50-90 to a three- hour 50-90. I also prefer doing a 50-90 every second day or longer to doing it every day.

Baby -sitting is not the issue as noted--you have to be there while the portable gen is running, so setting up a portable charger is not a big chore, and once you have it all going, you are free (while staying near the rig) for two hours to do whatever.

In order to arrange a two- hour 50-90 every second day, you have to balance your usage with your battery bank size in AH and your charger size, with sufficient generator size to run that charger.

Your options there depend on the size and type of your rig, and all sorts of things.

Solar is just a method to extend the time between generator recharges. How much time that gets extended is up to the weatherman,where you park, your latitude, and what time of year.

Each RVer has to learn himself what is possible for him by experience. He can get an indication of what is possible for him by seeing what others are doing. Each Rver is over 21 and must make his own choices.
epfd217
Explorer
Mar 25, 2017
Charging does not have to be a babysitting occasion, however, I feel like having your genny running IS a babysitting event.

I guess it depends on how the OP plans to use the charger the most.
SoundGuy
Explorer
Mar 25, 2017
johnm1 wrote:
The Boondocker, et al. units are in the 75 amp range and the "biggest and best" CTEK is 25amps. It looks like your's is 7amp? That sounds like lots of generator run time.

Did I miss something?

Yeah, this isn't about me but about you. We normally camp on electric sites but from time to time find ourselves without shore power so to that end I have a 1000 watt PSW inverter that allows us to make coffee, toast, run a couple of fans, etc, just as we would when on shore power. Genset run time is a non-issue for me because I no longer have one and instead recharge when we get home so that 7 amp CTEK which does do a true 14.4 volt bulk charge is just the ticket for my particular situation. Babysit if you want, if it were me in your situation I'd be investing in a PD9260, mounting it in the front pass through cargo compartment, and letting it do it's job automatically.
Sam_Spade
Explorer
Mar 25, 2017
johnm1 wrote:
And all of a sudden, I need to watch what we use and figure out how to replace what we use.

This is one of the reasons I'm on this forum.

And once again, you are making this MUCH more complicated than it needs to be, most likely. A LOT of people seem to fall into that trap.

A generator simply replaces the shore power.
IF....you get a generator and run it a few hours per day, you might even be able to fall back to your old "simplistic" habits with only a slight adjustment.

There is ABSOLUTELY no need for TWO converter/charger units in normal operation. One good 3 or 4 stage one will do everything you need. It is on and actively charging the batteries any time you have a 120 AC input, either by plugging in or by running a generator. It chooses the best charging rate based on the conditions at the time; mostly how much the battery needs.

The folks who insist on talking about equalization and optimum charging rates and manually adjustable chargers......are just obsessive, whatever the reason. Your average camper does NOT need to worry about any of that. You need to get a good handle on the basics before you even consider listening to that kind of chatter.

I think those who take "rookies" down those paths where they really don't need to go are doing you a BIG dis-service. Going camping with the family is supposed to be a restful activity. Obsessing over your batteries is the kind of thing that tends to ruin that and cause stress instead. Totally unnecessary.

JMHO, of course. ;)
red31
Explorer
Mar 25, 2017
johnm1 wrote:

Did I miss something?

nope! adj voltage (matching batt maker's recommendations) will take better care of you flooded batteries, just fully charge as soon as you have utility power.

I unitized BFL's ungly graph so if you consider 17% charge rate (75/440), that's ~2hrs to 80% from 50% vs 2hrs 50-90 @35%
johnm1
Explorer
Mar 25, 2017
I can learn to babysit and I can always take Mex's suggestion and add a spring wound timer switch between the charger and power source (generator).

The Boondocker, et al. units are in the 75 amp range and the "biggest and best" CTEK is 25amps. It looks like your's is 7amp? That sounds like lots of generator run time.

Did I miss something?
SoundGuy
Explorer
Mar 25, 2017
johnm1 wrote:
The Boondocker BPCM-xx is safe to use all the time? Even when plugged in 24/7 at home?

BFL13 wrote:
Yes but you must change the voltage yourself, it is not an automatic 3-stageer like the one you have installed now. Best to use the 3 stage one on shore power and only use the ADJ one for fast charging on the generator.

Which brings up an important point the OP must consider - do you really want to babysit any manual charger while you're camping, or even when at home, like some of these guys apparently do in order to achieve maximum effect OR would you prefer the charger do it all automatically, even though it may not be capable of quite the charge efficiency? I know what my answer is - I've got FAR better things to be doing when camping - i.e. nothing - than fool around with a charger. JMO.