Battery Charging Question Using Charger w/ Shore Power

[camaraderie]

Originally Posted by Herk7769

So, dipping my toe in this water ....

The WFCO 8935 is a 35 amp 3 stage converter (meaning it will create 35 amps of DC current at maximum output).

http://www.americanrvcompany.com/ass...s/wf8900ss.pdf

http://www.americanrvcompany.com/ass...ges/wf8900.pdf

The converter will supply charging amperage to the battery based on its 3 stage charge profile. As long as there are no other 12 volt demands on the camper (lights, furnace, fans, etc.), the great majority of that current will be available to charge your batteries.

Will that converter charge a huge battery bank? Yes it will.

Will it fill it quicker than a WFCO 8955 (55 amps) or a WFCO 8975 (75 amps)? No, because more current will be available while in Bulk charge (stage 1 - Capacity below 50%)

Once the converter switches to stage 2 (Absorbtion - above 50%) the ability of the battery to accept current becomes the limiting factor determining how long it takes to charge the battery. Your WFCO 8935 can easily supply the 10 amps or so the battery needs in stage 2.

In "FLOAT" (stage 3 - 90% to 100%) - all converters are basically the same, providing 1-2 amps till 100%; then cycling on and off as needed to maintain 100%.

Charging "efficiency" is what folks talk about. The time it takes to go from zero to 100%. The bigger the converter, the faster you get to 50%.

The only caveat to this is that a battery will only accept 20-25% of capacity in current in bulk stage. A 100 amphour batt will not charge any faster on a 50amp charger than on 25 amp one. In the case at hand, with 2 golf carts of 220amphours@12v...the ideal size would be 55 amps. Anything more is overkill.

[Jonol]

You can cut the charging time almost in half if you are using a regular bench 15 Amps deep cycle charger on battery 1 and live the Wcfo charger from the TT charge the Battery 2 and it is posseble by using a Marine Switch that cost you $25.
You can also do a lot more with this switch.

See diagram!

[SidecarFlip]

Don't understand the adversity to the WFCO Inverter. Mine operates just fine. for a cheap oriental unit.

[Herk7769]

Originally Posted by camaraderie

The only caveat to this is that a battery will only accept 20-25% of capacity in current in bulk stage. A 100 amphour batt will not charge any faster on a 50amp charger than on 25 amp one. In the case at hand, with 2 golf carts of 220amphours@12v...the ideal size would be 55 amps. Anything more is overkill.

Exactly. Bank size (and usage while charging!) is key when looking at the capacity (in amps) of the converter.

[A32Deuce]

Mine worked good till it started boiling the batterys. Then I went to AGM and a 4 way converter from go power.

[johnbryanpeters]

My WFCO WF-8955PEC works just fine. If it barfs, I'll probably go with a Progressive. If it ain't broke, don't "fix" it.

[CaptnJohn]

For others thinking of doing the same--- electric slides are not to be operated without a battery. I'm not certain anything else has that stated but every camper I have owned with electric slides has that written somewhere.

[jonshonda]

Originally Posted by Jonol

You can cut the charging time almost in half if you are using a regular bench 15 Amps deep cycle charger on battery 1 and live the Wcfo charger from the TT charge the Battery 2 and it is posseble by using a Marine Switch that cost you $25.
You can also do a lot more with this switch.

See diagram!

I was under the impression it is best practice to charge both at the same time using the same charger, as it will equalize the "pack".

[Herk7769]

Originally Posted by jonshonda

I was under the impression it is best practice to charge both at the same time using the same charger, as it will equalize the "pack".

Jonol is not using his pair of batteries " as a bank", but as two individual batteries (individually selectable and chargeable. If using as a bank, only an on/off switch is needed to disconnect the bank.

When wired as a bank, the wiring would look more like this: