Batteries Not Charging With Generator

[timkim]

Hello Fellow Forum Folks, Help......
We are living off the grid in our 1972 Airstream Tradewind, with no AC, just 2 deep cycle RV batteries hooked up parallel, they are the same and both are good. My wife and I don't have great electrical needs, all we use are 2 laptop computers and very occasional lights. We have a Magnatek 7445. I have been attempting to charge my batteries by running a Honda 2000 generator and plugging the trailer into it. The batteries are not charging. Is the 7445 supposed to be charging the batteries by plugging in a generator? Or am I assuming too much or maybe doing something wrong? Is the Magnatek 7445 maybe faulty? How can I check this thing out?
Thanks for your help!
Tim

[Mexray]

You'll need a digital DC voltmeter...

With the AC not plugged into the genny, check the voltage at the batteries - write it down...

Run the genny, plug the AS AC cord into the genny....

Check the DC voltage at the batteries again...write it down...has the voltage increased with the genny running? If so, you'll just have to give it time to recharge your batteries - it could take hours, depending on how low they are discharged...if your converter/charger is working, the DC voltage at your batteries should be a bit over 14 volts...

If the voltage test with the genny running didn't show and increase in the voltage, you'll have to work backwards from the batteries to find out why...

Check the voltage at both sides of the fuses that are in the battery circuit....is there a bad fuse?...dirty contact on a fuse?...

Check the DC output of your converter - is it producing DC voltage? if not, is the AC circuit breaker tripped in your AC circuit breaker box? if your voltmeter is a multi meter, you can use it (in the AC volts setting) also to check to see if you have 120 volts AC at the plug where the converter is plugged in, to insure you have AC voltage there...

these are some of the things to check...it's a process of elimination, so to speak...work back to the source...IE is you have DC voltage on the output side of the DC battery fuses, but no voltage at the batteries - then you have a wiring problem between those tow points, etc., etc...

good luck...

1. i would check to make sure the converter is powered
2. check the converter's DC output
3. check the fuse panel
4. check for increased voltage at the batteries...if good, then it just takes time, depending on the battery state of charge - if you ran down the batteries all the way, it could take as much as 6-8 hours to recharge them with a 45 amp converter/charger...


good luck

[timkim]

Thank You Mexray!!!
That's quite a list you put out here, and it is just what I need to get started on this problem.
I just bought an hydrometer today and tested the batteries an they were both in need of a charge. I ran the gen for about 3 hours the evening before and hadn't used any DC since then. So, I'm pretty sure the gen isn't charging the batteries. We have been running the laptops with the gen running so I know that we're getting AC from the gen. While running the gen the little inverter I have reads 13.5v and then when I plug the laptop into the inverter it brings it down to 13.2 then 13.1, then 13.0; it seems to be pulling the charge down pretty quickly in a relatively short time.

Anyway, I am just beginning to learn about how this old system works and your list gives me plenty to look into so I will get on it in the morning.
Again, Thank you for the lead.
Tim

[richinny]

if the batteries are a of the 'wet cell' variety and you can take the caps off, check to make sure the water level is above the plates inside. do not overfill the water as it will boil over when charging.

[AirsDream]

Did you ever get your 12v issues that you posted about back in May of '08 sorted out? It might be that something got hooked up wrong back when the PO put in the Magnatek ... you posted then about 12v difficulties.

So, a question: has your 12v always worked o.k. since then and this is a new phenomenon, or has it always been problematic? If the latter, seems to me that you need to totally review your entire 12v system for shorts, mis-hooked up wiring, etc. While it may take more than 2 or 3 hours to recharge your batteries from the genset, in that amount of time, it ought to bring it up to a reasonable state of charge, and it doesn't sound like that's happening. There are a good pair of articles on things 12 volt, starting here: The 12volt Side of Life (Part 1) ... good luck!

[timkim]

I found it! It was a loose connection tucked back in the compartment with the Magnatek. The wire that is needed to charge the batteries did not make good contact with the battery leads. I tightened them up and the batteries are charging as they should be.
Thank you all for your input.
Tim