Opinions have often been expressed, both on this and other RV forums, that most stock RV converters are inadequate to properly charge and maintain batteries and are often of poor quality. It is frequently suggested that they be replaced with an aftermarket converter, a Progressive Dynamics unit being very popular.I have just purchased a new Coachmen Apex TT (haven't yet taken possession of it) that will use two Trojan T-105 batteries. It comes with a WFCO 8955 PEC B 55 watt converter, a 3 mode converter with outputs of 14.4, 13.6, and 13.2 volts. A PD 9260 60 watt converter has exactly the same outputs in 3 of it's modes but also has an equalizing mode with 14.4 volts every 21 hr. for 15 minutes. I found no mention of an equalizing mode on the WFCO website.Trojan's website lists recommended charge voltages of 14.8 in absorption mode (slightly different that either converter), 13.2 in flat mode, and 15.5 (more than PD's 14.4) for equalizing. Regarding equalizing they state:"Many experts recommend that batteries be equalized periodically, ranging anywhere from once a month to once or twice per year. However, Trojan only recommends equalizing when low or wide ranging specific gravity (+/- .015) are detected after fully charging a battery." Trojan also states an equalizing charge can be done manually by unplugging a charger and plugging it back in, although I don't know if that applies to a golf cart or RV environment, or both, or to a converter as opposed to a simple charger.Considering that info I'm wondering if an equalizing charge every 21 hours is necessary or even desirable.Given the cost of these batteries, I would like them to last as long as possible. My question is, given the information above, is it worth the over $200 for a Progressive Dynamics, or some other aftermarket, converter. If the only advantage of the PD over the WFCO is the equalizing mode it seems that I could do a manual equalizing charge as needed per Trojan's guidelines and the WFCO would then serve equally well. Or, are there also issues with WFCO quality that I should take into account, or any other aftermarket converters worth considering?Thanks very much for any opinions and info that will help in this decision.Mike

If you have ever seen your WFCO actually go into SMART MODE charging then keep it. Most of us have never seen a WFCO Converter go into smart mode charging. I changed my 2008 model out for the PD9260C smart mode converter right away and never looked back... Maybe the newer ones are better now...I still use the WFCO Power Distribution Panel where all of the circuit breakers and 12VDC fuses are located. Roy Ken

"Equalizing" with the PD is actually just giving it a shot of 14.4 every so often when on its 13.2v Float to prevent stratification. It is not what is usually meant by "equalizing" (high voltage 15+)14.4v is not slightly different from 14.8v-- it is vastly different. To meet your Trojan specs you will need a different charger from the converter. EG, I use a VEC1093DBD for recharging at 14.8v and then go to the converter for the Float when that's done.

Hi,How do you use the RV? If the existing converter works, I'd be tempted to just follow BFL's sage advice and use a battery charger from time to time.The PD 15 minutes every 21 hours is to stir the electrolyte. Not a true equalization, at all.Depending on your use I would consider a modest solar system with a top notch charge controller. That would take care more or less automatically of all the equalizing needs.

I have had nothing but WFCO since 2005 . the old ones lasted 4 years and charged at 13.6v .My Trojans are original and working fine . The Trojan web site says not to equalize unless you have unbalanced cells. The one I just got charges at 13.2v when the load is low and goes to 13.4v with more load . Also I believe to equalize properly you have disconnect the load.

You are spending tens of thousands on a new RV and you are quibbling about a couple hundred bucks on a new PD. Pay the money--you'll sleep better at night knowing you got rid of the POS WFCO.

Should I Change My WFCO Converter? | Good Sam Community

landyacht318
Explorer
Dec 04, 2014
My MeanWell didn't even come with that.

But there is a bit more info online on it.

Would love to see what the Megawatt-400 can do into a depleted bank.

I have a pretty short run of 8 awg, and still set my MW nearly 0.2 higher than I want the battery, then back it down when amps taper to below 5 or so.
NinerBikes
Explorer
Dec 04, 2014
liketoride2 wrote:
jrnymn7 wrote:
Mike, just keep in mind, it's what's happening at the batteries that counts. You must adjust the power supply (up) for voltage loss across the wiring, from power supply to batteries. Therefore, the shorter and heavier the cable, the better. And the higher the amps, the greater the voltage loss. So, when charging, compare voltage at the power supply's output with that at the batteries, and you'll see there is a drop in voltage across the wiring. In my particular case, I saw .07v drop over 4' of 4ga at 40a.

I've been going thru some notes, and using a 45 amper on a 215Ah bank, amps were down to 40a, at 14.8v(at batteries), at about 84% soc, (at ~65F). Your bank is slightly larger, so you should see the MegaWatt's amperage maxed out 'til at least 85% soc, I would think. This means two things, essentially, 1) using a 40 amper on a less than 85% soc 225Ah bank means less Ah's replaced than is possible with a higher amp unit, within the same time frame, and 2) if you only charge the bank from 85% soc and above, a higher amp unit would be of no benefit. Nevertheless, you will be able to do a 50-85% in 2 hours, at 40 amps, and an 85-97% in about another hour, amps tapering. When amps taper to somewhere around 30a, at 14.8v at batteries, you'll know you're in the 90% soc range.

If you have a good idea how many Ah's you've used, you can easily estimate the time it will take to replace them. For example, at 40 amps, that's 40a/60minutes, during the 50-85% range on your size bank. That's .66a/min. So, if you're at say 75% soc (which is -56Ah's on a 225Ah bank), you can do a 75-85% (-56Ah to -34Ah, thus replacing ~22Ah)in about 35 minutes (diff of 22Ah / .666Ah/min. = 33 min.). So, a 75-97% would take about an hour and a half. The final 3% will likely take another hour, or more. And this is why many part time boondockers do 50-80's with as large a charger as they can, while on gen power, and then do a good 80-97% followed by a 97-100% top charge immediately after getting home.

Not doing a proper top charge, (and if indicated by SG readings, a proper EQ), after a week or two of doing 50-80's, will inevitably result in premature battery failure.

Thanks for this and all the other info from you and others. I'm going back through the posts on this thread and printing out those that are especially helpful.

I hope the Megawatt comes with some good instructions.

Mike

It pretty much comes with a Power Supply information sheet. Not much else.
liketoride2
Explorer
Dec 04, 2014
jrnymn7 wrote:
Mike, just keep in mind, it's what's happening at the batteries that counts. You must adjust the power supply (up) for voltage loss across the wiring, from power supply to batteries. Therefore, the shorter and heavier the cable, the better. And the higher the amps, the greater the voltage loss. So, when charging, compare voltage at the power supply's output with that at the batteries, and you'll see there is a drop in voltage across the wiring. In my particular case, I saw .07v drop over 4' of 4ga at 40a.

I've been going thru some notes, and using a 45 amper on a 215Ah bank, amps were down to 40a, at 14.8v(at batteries), at about 84% soc, (at ~65F). Your bank is slightly larger, so you should see the MegaWatt's amperage maxed out 'til at least 85% soc, I would think. This means two things, essentially, 1) using a 40 amper on a less than 85% soc 225Ah bank means less Ah's replaced than is possible with a higher amp unit, within the same time frame, and 2) if you only charge the bank from 85% soc and above, a higher amp unit would be of no benefit. Nevertheless, you will be able to do a 50-85% in 2 hours, at 40 amps, and an 85-97% in about another hour, amps tapering. When amps taper to somewhere around 30a, at 14.8v at batteries, you'll know you're in the 90% soc range.

If you have a good idea how many Ah's you've used, you can easily estimate the time it will take to replace them. For example, at 40 amps, that's 40a/60minutes, during the 50-85% range on your size bank. That's .66a/min. So, if you're at say 75% soc (which is -56Ah's on a 225Ah bank), you can do a 75-85% (-56Ah to -34Ah, thus replacing ~22Ah)in about 35 minutes (diff of 22Ah / .666Ah/min. = 33 min.). So, a 75-97% would take about an hour and a half. The final 3% will likely take another hour, or more. And this is why many part time boondockers do 50-80's with as large a charger as they can, while on gen power, and then do a good 80-97% followed by a 97-100% top charge immediately after getting home.

Not doing a proper top charge, (and if indicated by SG readings, a proper EQ), after a week or two of doing 50-80's, will inevitably result in premature battery failure.

Thanks for this and all the other info from you and others. I'm going back through the posts on this thread and printing out those that are especially helpful.

I hope the Megawatt comes with some good instructions.

Mike
BFL13
Explorer II
Dec 03, 2014
Yes the VEC needs to be clamped onto the batteries, plugged in, and buttons pushed.

Just about any modern deck mount converter could be used as a portable charger. Those plug in and will start and stop with the 120v availability. You cut off one end of a set of jumper cables to fit in its output terminals as the way to clamp to the batteries.

If the concern is to get higher than the usual converter voltages, then for $50-70 more than the VEC there is the PowerMax adjustable one at Randy's. VECs are getting hard to find anymore.

Only thing is there is no ammeter display on a converter to show charging progress like there is on portable chargers like the VEC, but eBay sells ammeters.
pianotuna
Nomad III
Dec 03, 2014
Hi CJW8,

Yes, you have to push "buttons" on the vector every time you wish to use it.
CJW8
Explorer
Dec 03, 2014
BFL13,
With your VEC1093DBD, do you have to set it up (push buttons) each time you start your generator? In other words, suppose you have it connected and it is morning and you start your generator, do you have to go to your VEC1093DBD and push some buttons to make it do what you want or does it automatically start charging with no human interference?

I am well versed as I have been through most of the learning curve. I am thinking of my two sons who are new to RV'ing and are clueless and are both are already complaining about batteries not getting through the night. I know what the problem is but it will take time for me to educate them. In the mean time I want to suggest a portable smart charger that requires no buttons to be pressed to get it going. I have a B&D 40 charger that I think is similar to yours but it requires that you push the start button.
NinerBikes
Explorer
Dec 02, 2014
Snowman9000 wrote:
Niner, does that 50A shunt get very warm? From reading I've done, I'm finding that many shunts will change their characteristics if used with more than 50% of their rating over time. I suspect the cheap Chinese ones are particularly like that. The solution would seem to be to go with a 100A meter and shunt. However, problem with the 100A & 200A ones is that they are not mounted on an insulated base. I'm installing one of each on my MH now, and have had to use a gray PVC C or T fitting to insulate them. The 100 and 200 shunts fit perfectly into said 3/4" fitting, and can't slide out of the end openings. Just some random thoughts on using cheap Chinese shunts....

No way I am putting my finger on a hot shunt to find out, and what happens at 33 amps will not be the same as what happens at 40 amps. His unit is more likely to put out the rated 36 amps, also.
jrnymn7
Explorer
Dec 02, 2014
Mike, just keep in mind, it's what's happening at the batteries that counts. You must adjust the power supply (up) for voltage loss across the wiring, from power supply to batteries. Therefore, the shorter and heavier the cable, the better. And the higher the amps, the greater the voltage loss. So, when charging, compare voltage at the power supply's output with that at the batteries, and you'll see there is a drop in voltage across the wiring. In my particular case, I saw .07v drop over 4' of 4ga at 40a.

I've been going thru some notes, and using a 45 amper on a 215Ah bank, amps were down to 40a, at 14.8v(at batteries), at about 84% soc, (at ~65F). Your bank is slightly larger, so you should see the MegaWatt's amperage maxed out 'til at least 85% soc, I would think. This means two things, essentially, 1) using a 40 amper on a less than 85% soc 225Ah bank means less Ah's replaced than is possible with a higher amp unit, within the same time frame, and 2) if you only charge the bank from 85% soc and above, a higher amp unit would be of no benefit. Nevertheless, you will be able to do a 50-85% in 2 hours, at 40 amps, and an 85-97% in about another hour, amps tapering. When amps taper to somewhere around 30a, at 14.8v at batteries, you'll know you're in the 90% soc range.

If you have a good idea how many Ah's you've used, you can easily estimate the time it will take to replace them. For example, at 40 amps, that's 40a/60minutes, during the 50-85% range on your size bank. That's .66a/min. So, if you're at say 75% soc (which is -56Ah's on a 225Ah bank), you can do a 75-85% (-56Ah to -34Ah, thus replacing ~22Ah)in about 35 minutes (diff of 22Ah / .666Ah/min. = 33 min.). So, a 75-97% would take about an hour and a half. The final 3% will likely take another hour, or more. And this is why many part time boondockers do 50-80's with as large a charger as they can, while on gen power, and then do a good 80-97% followed by a 97-100% top charge immediately after getting home.

Not doing a proper top charge, (and if indicated by SG readings, a proper EQ), after a week or two of doing 50-80's, will inevitably result in premature battery failure.
Snowman9000
Explorer
Dec 02, 2014
Niner, does that 50A shunt get very warm? From reading I've done, I'm finding that many shunts will change their characteristics if used with more than 50% of their rating over time. I suspect the cheap Chinese ones are particularly like that. The solution would seem to be to go with a 100A meter and shunt. However, problem with the 100A & 200A ones is that they are not mounted on an insulated base. I'm installing one of each on my MH now, and have had to use a gray PVC C or T fitting to insulate them. The 100 and 200 shunts fit perfectly into said 3/4" fitting, and can't slide out of the end openings. Just some random thoughts on using cheap Chinese shunts....
NinerBikes
Explorer
Dec 02, 2014
Glad you found something that will work for you. Now to figure out where to install it out of the elements, and close to the battery, with some 8 gauge wire and some ring terminals.

The shunt and amp meter should be part of the install package also, it makes it very easy to adjust the charging voltage of the unit and eliminates the guess work. You'll learn quickly, by how many amps are being flowed at what voltage, the state of charge on your batteries.