generator

[Tim]

Does anyone have an opinion about the best generator for battery charging while boondocking?  And should I use a 120V battery charger, or the "optional DC cables for battery charging" ?

[mike4947]

Well any genset less than 1KW will only have DC posts with a 4 amp output. Even the expensive EU1000i's and EU2000i's from Honda are limited to 8 amps from the DC connections.
So the easy fast way is to hook up an external charger to a genset. As for the size of the genset, Even a 500 watt continuous power model will power a 40 amp charger. 40 amps times 12 volts equals 480 watts.
My little 650 watt 30 year old Honda doesn't even break a sweat with my 25 amp smart charger.

[Tim]

Thanks again Mike,

I was thinking of the Honda 1000 inverter generator.  I have a Deltran Power Tender Plus 12v @ 6A.  It is described as a 4-step charger.  Do you think this would be ok for charging 2 Trojan T-105s?  Also, I guess I could just hook up from generator to pop up main 120v power cord as I think the WFCO converter/charger in my Fleetwood  is a decent charger.  Any other thoughts?

Tim

[tlhdoc]

Thanks again Mike,
 
 I think the WFCO converter/charger in my Fleetwood is a decent charger. Any other thoughts?
 

What trailer do you have?  A lot of people say the converter is not a good charger, that you should use a regular battery charger.

[Tim]

I have a 2004 Fleetwood Bayside.  It came with a WFCO 8700 series converter with 3-stage battery charger.

[mike4947]

Tim, you'd definitely be ahead using the genset to power the converter. IIRC there's about a maximum of 20 amps usable from the converter's 30 amp max output to go to battery charging. Now if you put on a bunch of 12 volt draws; Lights, etc you won't have that much available for recharging. BUT, it won't hurt to use the 4 stage occassionally at home just to make sure you aren't sulfating the battery over time. That's one of the reasons I bought the smart charger was for it's auto sulfation cycle.

[Tim]

Another question, if I were to replace my wfco converter with a Progressive Dynamics 9100 series w/ charge wizard (which many people suggest); is it possible to have a converter/charger with too high of amperage for my setup of dual trojan T-105's with back-up battery charging with a Honda EU1000i  generater. I quess what I am asking it would it make sense to replace converters and if so  which PD 9100 converter would be a good choice for optimal battery charging.

[mike4947]

Well, you don't "replace" a converter in a PU with a Progressive converter. You replace/bypass the transformer/reftifier section and 12 volt fusing. SInce your present converter also include the shore power hookup and the 120 volt breakers you still need part of the old converter.
Most RV's have a seperate 120 volt breaker panel and the PD converter just wires into a breaker mounted in that panel.
So it's either keep the old converter and add the PD or replace it with a breaker panel and the PD.
 
As for the charging amperage the rule of thumb is to take the capacity (20 hour rating) and divide by 10 for the effective maximum charging rate. Folks say you can use 20% rather than 10%, but prolonged charging at the 20% rate can and will shorten batty life over time.
Again that's why I chose the Schumacher 2/12/25 amp smart charger. The 12 amp setting works for most single batteries and the 25 amp rate is good for most dual batteries.

[jimgolden]

ok guys

I was on the same wave of thought as Tim, sorta. I have 24G deep cycle battery that I wanna charge out in the sticks...

how long would it take to charge it w/a generator If I plug straight into
my PU (05 Taos, same WFCO coverter)?

I can't really go wild increasing batt. size, as I have to keep my tongue weight down, and I dont wanna have even more crap (charger) too.

am I being naive here in thinking this is logical? I have 3 10 day+ trips
this summer and I don't plan on being anywhere near shore power @ anytime during them...

[Tim]

Mike,

So are you are saying that the WFCO unit is going to charge @20A and not @30A? And Trojan Battery is recommending a charger with an ouput of 10-13% of 20hr capacity (with dual T105's at 225amp-hr; 10-13% of 225 = 22-29 amps)  SO, while charging with the WFCO at 20A is a bit lower than the recommended 22-29 amps, it is still alot better than with my seperate Deltran charger at 6A, correct??  And is that also mean about 3 times faster than with the 6A Deltran??  AND, if I wanted to try to charge a bit more quickly I could get a Schumacher like you have and run it off the 1000w generater at 25A which would be right at the recommedation of Trojan battery??   Is this reasoning correct?  Thanks for all of your help and expertise as I try to understand all of this.

Tim

[mike4947]

Essentually correct, with the realization that as the battery(s) reach full charge (over 80%) they will accept less amperage.

As an example: a battery discharged to apx 50% will take as longer going from 80% to 100% than from 50% to 80%
 
JMHO, but I prefer using an external charger over any converter mainly because on the newer smart chargers they also include a percentage of charge reading and the charger knows when the battery is "full". With the converter you're never sure what's in the battery. LOL