Thoughts on Cheng Converter

[IMDSailor]

My 2011 Serrano 31V has a Cheng WF-9855 55 Amps DC Output, (15 Amps AC Power Cord). These are the specs;

Bulk Mode.
In this mode, the output voltage of the converter will switch to 14.4 Vdc range for a maximum of four

hours. If the converter cycles between “Absorption and Bulk mode,” there could be a shorted battery cell or some

other issues.

Absorption Mode.

During this mode, the converter output is in the 13.6 Vdc range. This

is the normal operation mode. This mode provides the 12 Vdc and current required by the 12 Vdc RV system, as well as slow charging the battery.

Float Mode.

If the RV is not being used for approximately 48 hours, the converter will automatically go into the “Float mode.” In this mode, the converter is charging the battery with a trickle voltage of 13.2 Vdc range. When

the converter senses a demand (by turning on lights), the converter automatically returns to the “Absorption mode” 13.6 Vdc range.

In reading other threads in here it would seem that the Bulk charge is low, opinions expressed in other threads seem to indicate the 14.7 or better is where you want it.
I'm not lookinging to do any boondocking anytime soon, but was wondering if people had any thoughts on this Converter/Charger. I also have a Tundra 1200HD Inverter, if people want to weigh in on that too I'd like to hear opinions.

Thanks.
Stewart

[RedneckExpress]

Given that their numbering is identical to the WFCO series Converters, it likely is a rebadged WFCO unit, and if you have an expensive battery array, I'd upgrade to a better smart converter.

I got rid of my WFCO series converter for a PowerMax Boondocker and have been enjoying far better and more battery safe performance than my WFCO ever put out.

[IMDSailor]

Thanks for you input. WFCO=Cheng. One makes the other, just not sure which way it goes.
I have 2 x 12V Chassis batts and 2 x 6V Coach. I'm assuming the Converter/Charger only charges the Coach batts.
I recently installed a Trik L Start as I have a 15W solar panel trickle chargeing the Coach Batts while it's in storage to help maintain the Chassis batts

[RedneckExpress]

Quote:

Originally Posted by IMDSailor Thanks for you input. WFCO=Cheng. One makes the other, just not sure which way it goes. I have 2 x 12V Chassis batts and 2 x 6V Coach. I'm assuming the Converter/Charger only charges the Coach batts. I recently installed a Trik L Start as I have a 15W solar panel trickle chargeing the Coach Batts while it's in storage to help maintain the Chassis batts

Yup, and the WF units never go to proper voltages, which is why you want to run, don't walk, and replace it as soon as possible. I had a WF-9835, it did a wonderful job of killing 2 $200 Trojan SCS225 batteries in under 5 years even with regular watering.

[KJINTF]

Good to see everyone has an opinion
For me the WFCO charge voltages work just fine and have kept my 4 year old 6Vdc CC Batteries in good shape, hope to get another 4 years from them. That said the WFCO 45 is not used as the primary charger and we do not often plug in to shore power, or use the on-board genset if ever when camping. The WFCO is used constantly for three or four months during the winter and does not harm the batteries with 13.2Vdc. I don't have to add any water to the batteries during winter plugged in storage time. The WFCO will charge your battery bank just fine - might take a bit longer than some others but will not hurt the batteries. Depending on type and size of your battery bank. Now if you want to go buy a new converter I would be happy to take the old unit off your hands

[RedneckExpress]

Quote:

Originally Posted by KJINTF Good to see everyone has an opinion For me the WFCO charge voltages work just fine and have kept my 4 year old 6Vdc CC Batteries in good shape, hope to get another 4 years from them. That said the WFCO 45 is not used as the primary charger and we do not often plug in to shore power, or use the on-board genset if ever when camping. The WFCO is used constantly for three or four months during the winter and does not harm the batteries with 13.2Vdc. I don't have to add any water to the batteries during winter plugged in storage time. The WFCO will charge your battery bank just fine - might take a bit longer than some others but will not hurt the batteries. Depending on type and size of your battery bank. Now if you want to go buy a new converter I would be happy to take the old unit off your hands

So, in reality, you really don't use your WFCO like it normally would be used, as a primary charger, so your batteries have really been spared the abuse of regular use against a WFCO unit.

I'd be more than happy to supply the countless threads folks have posted on RV.net about the constant problems they've had with the WFCO units, who do use them as their main chargers and plug them in regularly.

I had 4 gauge wire run to my unit, it just wouldn't drop out of 13.6 volts and kept boiling off water, add in that it ran the de-sulfation cycle ever 24 hours and you end up with batteries that have been destroyed.

They're not very good chargers and that was my one and only I will ever deal with. Randy @ Bestconverter recommends against the units, even though he sells them and he's one of the major informational resources for RV chargers of all varieties.

WFCO, just like Centurion, Magnetek and Paralax, are junk converters.

[KJINTF]

Everyone is intitled to their own opinion
Guess if everyone else thinks they are junk I should as well......

For us the unit works fine and I am sure for many others it works fine as well
Keep an eye on battery voltage and water level
Remember a little maintenance goes a long ways

As a side point I do indeed understand electronics and proper multistage battery charging. Even installed a Sterling Power BtoB charger to get a proper multistage charge from the 130amp engine taper charge alternator system for my deep cycle batteries. Maybe you boiled your batteries from the engine alternator trying to charge a deep cycle set in addition to the standard starting battery.
Just a suggestion

Just trying to save the OP a few bucks - Again if he wants to toss it I would be happy to receive yet another nice little converter - always some use for more 12 Vdc sources around my electronics workshop. A few simple modififctions and all is good

Keep an eye on your battery voltage and water level get a good voltmeter you will be OK - fine

[IMDSailor]

Thanks guys, I just bought this new to me coach a couple of months back, so I'm not ready to start shoveling money into it just yet, heck haven't even camped in it yet. I'm just trying to get a handle on it's various bits and pieces. I didn't get all the manuals so between Google and here I'm trying to fill in the blanks, this is my first RV so there are many blanks.
I really do appreciate the input.
Stewart

[mgscott4]

I think alot of the problems some people are having with their WFCO charger (or any converter) may come from improper installation. My factory 06 Hurricane came with a 55 amp WFCO and was boiling out the batteries. But looking into it I found out what the real problem was. There was too much voltage drop between the charger and converter.

They installed it under the bed and 18 feet from the batteries and with # 8 wire. Once I relocated it close to the batteries (next Compartment within 3 feet) and connected it with # 2 AWG wire it works much better. It now sees the correct voltage it is putting out. I did have to relocate the dedicated 120 volt outlet to power the converter too. I think it has an internal temperature sensor, so now it is in an outside bay and "feels" the same temperature as the batteries.

I also put a 100 amp catastrophic fuse inline close to the batteries "just in case". I also ran # 2 wire to DC distribution box 18 feet away and fused it too.

[Ed-Sommers]

The major Battery companies suggest a bulk charge of around 14.8, and that level should be held for between 2 and 4 hours before dropping down to the 13.X level, if maximum performance is required from said batteries.

There is, however, those that say a 80% (in terms of voltage) charge is sufficient as long as the batteries never drop below a 50% (static) total charge, and that 14.4 is fine.

I am personally an advocate of the 14.8 (actually, twice that as I wire by batts in 24 volt configuration) level, and a charger is only used if forced to by weather making my 1200 watts on the RV's roof insufficient for the job, and then I use the 14.4 with a charger and letting the solar finish off.

When using the 14.8 level, an equalizing charge is, in my experience, not needed (normally). But with the 80% practice, it is.


Ed
Navy Ret.

[Shadowcatche]

It is a must that voltage be monitored. Our teardrop was wired by some one who did NOT know what they were doing. The AC common and DC negative were both "grounded" to the frame. It fried both the AGM battery and the Progressive Dynamics converter and I found out because the voltage monitor told me the converter was not coming down off of boost mode.