12 Volt Converter Upgrade

[waiter]

Upgraded the original Equipment Converter to a new technology power supply.

The original unit has a history of cooking batteries and only puts out 25 amp.

The new WFCO 9855 has a three stage charging system so it can do a trickle charge all the way up to a 55 amp charge.

You can read about it here.

http://www.bestconve...t-Kit_p_47.html

The upgrade went almost exactly as the instructions said. I say "almost". In my particular unit, there is a 45 amp fuse in the 12 volt line, I had to reposition this fuse and drill some new mount holes. Other that that, perfect.

These are the Instructions for doing the upgrade:

http://www.bestconve...FCO_ep_8-1.html

NOTE - I also added additional Circuit breakers and a MAIN circuit breaker. (not shown in these photos) - Scroll down to see how I did this.

BEFORE CONVERSION

AFTER CONVERSION

REPOSITIONED FUSE

[RVdaytrader]

Have you tested the charging capabilities of the new converter yet by putting an amprobe on it to measure charging amps??

I am looking to upgrade mine as well.

RVdaytrader

[waiter]

Nothing quantitative yet. Just simple DC voltage checks.

With the battery disconnected, I see 13.52 Vdc on the DC circuits when Shore power applied (Converter supplying all the DC power)

Battery connected, I see 13.02 Vdc (no shore power, battery has good charge)

It jumped to 13,52Vdc when I applied Shore power. (Converter doing a slight charge to the battery)

When I first apply shore power, I don't hear the usual CLUNK, Instead I hear the fan kick on for a couple seconds.

[Gulfstream Greg]

Nice! You should repost this in the Improvement and Do-It-Yourself Projects to Share!

[waiter]

Two additional items you may want to consider when upgrading your converter; Adding an Shore Power Circuit breaker, and putting the 120 Vac circuit on their own breaker. This Mod will cost between $6 and $20 depending how much the circuit breakers cost

2 each - Double 15 amp - $3.00 at Menards. You want the Seimens or Cutler Hammer compatible breakers)

I reused the original RED 20 Amp breaker as the "MAIN" 20 amp breaker, and separated the loads that were feed by the Blue breaker and put them on their own 15 amp breakers. This way, I can turn off the different circuits individually if there are any problems.

Remember , The breakers are not there to protect the load, the breakers are there to protect the wiring in case the load become defective.

WARNING *** UNPLUG AC POWER BEFORE ATTEMPTING TO DO THIS ***

This is a photo of the original Converter with circuit breakers;

1) The Shore Power input line (AC Cord) is not fused or protected. It goes to a terminal that feeds the Circuit Breaker backplane. (top middle)

2) All the 120vac outlets, including the 12 volt converter are all tied together with a red wire nut. (left side) and protected by the Blue Circuit Breaker (15 amps).

3) The Red circuit breaker (20 amp) is for the Air Conditioner (I don't have one, I have an exhaust fan)

Remove the two breakers (The top pops out, then a slight lift to unhook them form the backplane)

Remove the wires from the bottom of the breakers.

Remove the Shore Power wire from the lug, then remove the lug from the circuit breaker backplane (3/8 socket). If you don't remove this lug, you can't add the third breaker.

You can buy double breakers, I used 15 amps as I don't have an Air conditioner.

I removed the wires from the red wire nut and put each load on its own 15 amp breaker. This allows me to turn off individual loads in the event of problems.

Install the two double 15s where the Red and Blue used to be, then install the Red on the left position. (Hook the bottom of the breaker onto the backplane, then push in at the top)

Connect the Shore Power wire to the bottom of the RED 20 amp breaker. This breaker will become your Shore Power MAIN input breaker.

NOTE - The photo on the left shows a 30 amp MAIN breaker, I changed this back to re-used the RED 20 amp breaker as the MAIN.

MAIN 20 amp RED

#1 15 amp - 12 Volt Power Converter

#2 15 amp - Air Conditioner

#3 15 amp - Outlets right side (including Frig)

#4 15 amp - Outlets Kitchen and Sofa

Since I had the sofa removed, I took a photo of the back of the converter

[Sandro L]

find out the charging rate, its not 55amps dedicated to charging. the original 25 amp unit has a pathetic 3amp charge rate. im thinkin of leaving the original and just buying a 15 amp battery charger and using a split cord to have either the generator or shore power connected to both the 25 amp converter charger and the 15 amp charger. making it a 40 amp system for alot less money. what do yall think?

[waiter]

There is a very good description of howw the converter changes voltage.

It does charge at a high current if needed.

Here is the manual for the WFCO 9800 Converter:

http://www.wfcoelectronics.com/documentation/manuals/Manual%20-%20WF-9800%20English.pdf

[Gulfstream Greg]

Here is some great information on batteries http://www.windsun.com/Batteries/Battery_FAQ.htm

[Totem]

find out the charging rate, its not 55amps dedicated to charging. the original 25 amp unit has a pathetic 3amp charge rate. im thinkin of leaving the original and just buying a 15 amp battery charger and using a split cord to have either the generator or shore power connected to both the 25 amp converter charger and the 15 amp charger. making it a 40 amp system for alot less money. what do yall think?

aren't you worried about sulfation of the batteries at 55 AMP? How many batteries are in your setup? This was great information to find out that the shorepower charger was putting out 3 Amp; it explains why it takes a week to charge a dead battery on shorepower. Also makes me feel really awesome about my solar and wind setup that each put out 2 Amp; together they are 4 on max output and had I had a generator to charge my batteries it would have only been 3. Looks like mother-nature can out-pace the stock converter.

[Maineah]

aren't you worried about sulfation of the batteries at 55 AMP? How many batteries are in your setup? This was great information to find out that the shorepower charger was putting out 3 Amp; it explains why it takes a week to charge a dead battery on shorepower. Also makes me feel really awesome about my solar and wind setup that each put out 2 Amp; together they are 4 on max output and had I had a generator to charge my batteries it would have only been 3. Looks like mother-nature can out-pace the stock converter.

It's just capable of 55 amps full load it is voltage regulated. With out a doubt the best upgrade you can do is a modern converter/charger not only is the old charger's charge rate poor the voltage is very poorly regulated and will boil the water out of the battery over time.

[Totem]

It's just capable of 55 amps full load it is voltage regulated. With out a doubt the best upgrade you can do is a modern converter/charger not only is the old charger's charge rate poor the voltage is very poorly regulated and will boil the water out of the battery over time.

I believe the "boil the water out of the battery" is when it is left in for prolonged periods of time in shore power because the original stock charger is a "dumb" charger with no shutoff; hence after the battery has reached its saturation or close to saturation point; the plates sulfate. This can also occur in charging systems that apply too much amperage in too short a period of time.

High Amp or quick chargers can damage a battery too if not used properly. The one you have seems intelligent an d has smart sensing that probably regulates how much charge is applied. I lost a battery this summer when i left my rv plugged in for 3 weeks on the old school charger. I kept the battery though; I am going to try the epsom salt trick on it.

Now here is something that most people might not think of but I am heavily considering finding the charger wire and applying that through my solar charge controller. You have stated it runs about 3 Amps and we know its putting out under 14 V. The solar controller has a shut off at saturation point which keeps a cell from sulfating. Thoughts?

I

[stamar]

find out the charging rate, its not 55amps dedicated to charging. the original 25 amp unit has a pathetic 3amp charge rate. im thinkin of leaving the original and just buying a 15 amp battery charger and using a split cord to have either the generator or shore power connected to both the 25 amp converter charger and the 15 amp charger. making it a 40 amp system for alot less money. what do yall think?

i think thats brilliant....

im thinking of just tearing out the converter box and getting rid of useless ballast, and then having a battery charger and an extension cord.

[Boots]

I agree that putting in a modern converter / inverter will save you a lot of grief in the long run, and will probably save the battery from premature failure. By the way, battery overheating is a function of the amount of energy that is being put into the battery itself, if the battery cannot absorb any more current, it reacts by disspating that heat inside the case. So there is a benefit from modern chargers, when equipped with a battery monitor, as temperature goes (regardless of what stager the charger is at) the current is scaled back incrementally until the battery temperature drops. I recall that car alternators are designed to only supply apporoximately 10% of the car's battery capacity, so if you have a 950 amp/hr rating then you could expect to see a maximum of 92 amps, which is a lot (1242 watts) pumped into that small case. Coach batteries are likely not to accept such large currents, so it would not be surprising to see charge rates in the 20 - 40 amp range. If you install a more modern charger say capable of higher current rates, then overheating is likely. By the way, one of the best practices of such any such upgrade is to increase the charger's wiring going to the battery to carry the new rated out put. So if you originally had a coach with #8 wiring going to the battery, for a new charge rate of 55 amps (maximum) you would need a #0 AWG wire.

If you attempt to put 55 amps down a #8, in very short order you would have a fire, which you likely could not stop. Which the brings me to #2 best practice, fusing, for all the same reasons, installing a fuse between the output of the charger and the battery is required by code. Again on a #8 wire at 10 amps (depending on your battery capacity) a fuse of 30 amps is required, when you move up to 55 amps, you require a 300 amp fuse (time rated); some put fuses on both the positve (red) and negative (black) wires to protect both wires (as required by code) Check BlueSeas website for more on wiring and fuses.

Cheers

Brian

[Redrum123]

What is your AH battery and how long does it take to charge with the new converter?

[Maineah]

I think you will find most of the chargers are fused at 30-35 amps internally. Because the charger is capable of 55 amps it does not mean it will deliver 55 amps only that it can don't forget it is also powering all of your lighting, fans etc the load side is the critical issue with fusing the more crap you used the higher the demand like an inverter running your microwave. A mostly charged battery will draw little recharge current, as it discharges its resistance increases demanding more amps to recharge. Batteries are both capacitive and resistive. So yeah a dead battery can draw more current but otherwise it will not be real high and the charging system is only voltage dependent for regulation.   A #8 wire is good for 30 amp load it's the length becomes a factor with voltage drop. A battery isn't a heavy resistive load  it's what the battery can deliver in amps not what it needs to recharge. My camper has a charging system that connects to my truck through the truck wiring there is a pair of 80 amp batteries on the tong, the alternator is capable of a 140 amps the supply wiring is a #8 about 20'  with a 30 amp fuse it's more than enough to keep the batteries charged.