WF-8955 where is the other fast charge?

[horton333]

So its raining and I am trying to learn the new trailer and nothing I try seems to be able to pry anything more than 13.6 voltages out of this supposed 3 stage charger. Where's the14.4?! Even with drying as low as iamwilling to on the battery Max is 13.6. Seeing other posts it seems like I am not the only one. Is there any solution to this ( don't need to know about competitors products, thanks)

[RJsfishin]

The fact probably is, if a wifco was ever to go into 14v charging amps, it wouldn't do it for long. If they smoke loafing in 13v mode, what do you suppose they would do at 14v.
What the astonishing part is, they still make them, and dealers still sell them, and the dealers I talked to, play ignorant to the fact that they are junk.
What they need is a class action law suit, so people like my brother in law can recoop his $400 back from the shysters out there still selling this junk.

[RoyB]

I saw 14.4V only one time for about 5 seconds. This was with the WF8900 unit directed connected to the battery terminals with about 6-inches of cable leads.

I kept my WF8945 brand new converter as a back-up unit and got me a PD9260C. I needed more current capacity anyway with my adding of additional batteries... You will need to have around 20AMPs DC current capacity for each battery in your battery bank if you want to do a 50% charge state to a 90% charge in a quick three hour charge period. The PD0260C goes into 14.4VDC the first time you plug it in. You also have a remote control unit that you can force it into any of the three charging voltages 14.4-13.6-13.2...

If you have some time on your hands read up on previous posts of the WF 8900 series converter not going into boost charge mode... You are not alone by any means...

Roy Ken

[time2roll]

Getting to 13.2 during initial charging is commendable. Needs to be even lower.

If it jumped to 13.6 then the 13.2 may have just been float mode and the real voltage was the 13.4 or 13.5 as you saw in other tests.

My 8955 only worked a few times with #2 wire into four heavily discharged golf batteries. OTOH 20 seconds of microwave through the 1800w inverter would drop voltage below 12 (while charging) and it would then be in boost mode every time.

[BFL13]

Don't forget that 13.2 is 'as seen' at the converter, so if there is voltage drop on long thin wire from battery to converter, the battery may be under 13.2, but the converter will see higher than that.

So part of the deal is to have low resistance between battery and WFCO as well as the other business wrt charging rate and SOC.

[horton333]

To elaborate a bit more. I took the voltage, measured at the converter's connection to the bus bar, to below 12 volts, twice by draining the battery. Once I tried with only parisitic load plus battery and the other I kept about 20 ampres load from the lights plus battery when I switched a.c. back on. In both cases it would start at like 13.2 and then in a couple of minutes go to about 13.6 and sit there in both cases till I got bored. I had also tried some much less severe cases. Similar results except the starting voltage would be like 13.4 or 13.5, and then stop at around 13.6. This puppy does not seem to care what the battery is doing from what I can see.
I am not willing to mess with the configuration, I already have what works well from the old trailerfor fast charging, but I connect directly to the battery and that gets noring. Quickly.
If someone has a schematic that may help.

[BFL13]

smkettner wrote:
You need sufficient load or battery draw to have voltage AT THE CONVERTER sag below 13.2 volts.
Not an easy task actually.

Far better to get a PD9260 or 55a IOTA with IQ controller.

To elaborate on that 13.2 business:

when you first apply a charger to a battery, there is an initial voltage spike from 12.x to 13.x. If the charging rate is high (amps vs AH size of battery bank) the spike will go above 13.2, can even hit 14 or whatever.

With a given charging rate, the next variable is the battery's state of charge. If it is higher in 12.x voltage, it will be easier to spike it above 13.2, so the idea is to have the charging rate just right and the SOC low enough that the initial spike is under 13.2, after which the battery voltage slowly climbs under the recharge in the usual way.

It happens that with the WFCO (and early model years PowerMaxs before they fixed that in 2011/12 ISTR) you need to get battery to just under 50% SOC and not hit it with too many amps so the spike is under 13.2 and it will go to 14.4v.

The reason smk is always saying you should try a 35amp charger instead of a 55amp is to get that charging rate down so that at 50% SOC it will go into 14.4 and not spike over 13.2 like it does with a 55 amper. However that still leaves you with a 35 amp charge instead of a 55. If you want a 55 rate and you can't get more than 13.6, you do need a different charger (of which there are several choices)

OTOH, if you want to keep the 55amp WFCO, you could try it on four batteries instead of just two. That halves the charging rate, so you might get your 14.4. Just takes a long generator run time to do a 50-90 on four batts starting at only 55amps! 😞

(I like to use 140amps to recharge my four 6s. I don't have a WFCO! I have a 100amp PowerMax plus a 40 amp VEC1093DBD and run both together from my Honda 3000)

[time2roll]

You need sufficient load or battery draw to have voltage AT THE CONVERTER sag below 13.2 volts.
Not an easy task actually.

Far better to get a PD9260 or 55a IOTA with IQ controller.

[pianotuna]

You can attempt to remedy the situation by increasing the cable size from the wfco to the battery bank. Try #2. You can move the converter closer to the battery bank using thicker wire. Neither of these suggestions work all the time, or even most of the time.

You MIGHT be able to pop the box and twiddle some internal knobs, but don't do so unless you are fairly expert. You may let out the magic blue smoke. In which case you may want to change brands.