Jump to content
Darryl&Rita

Magnum ME-2012 still struggling

Recommended Posts

After swapping out the AC board, the inverter/charger will randomly struggle. The owner asked me over this weekend to look at it. It's cycling between charging, and "DC Overload". The AC output cycles with the overload, causing chaos in the bus, microwave hums when connected to power, TV turns on and off, etc. I'm thinking the batteries are on their last gasp, as a 25 amp Wal-Mart battery charger for 15 minuets will bring the Magnum around. I suspect the cells aren't holding the depth of charge they should be, get pulled down, then the Magnum struggles to bring them back up. I can't find my toaster battery tester, but may go to Harbor Freight to get one yet.
Any other ideas?

Share this post


Link to post
Share on other sites
3 minutes ago, SWharton said:

Why don't you take the batteries to WMT and have them tested.

80 lb Trojan T-115 batteries x 4. Easier to buy a replacement tester. On top of the local WMT being the worst place I've ever been subjected to.

Share this post


Link to post
Share on other sites

Thought they were WMT batteries for some reason.

We have always had good service from WMT

Edited by SWharton

Share this post


Link to post
Share on other sites

 I think you are on right thoughts on the batteries having trouble. Which the magnum is getting confused as to what volts it may be seeing.

 

 I will suggest if it is possible to install a known good battery. Possibly without removing the other batteries. That may give a better answer to your guestion.

 Feel the batteries to see if they are warm on the outside. Eliminate any warm batteries. Then separate all the batteries, test each one for the proper voltage. Then just use a battery with the proper voltage.

  I carry some spare long cables in my work vehicle for this problem. Then I  can install another battery for a test.

 

 A least there is no snow on the ground,.    Vern

Share this post


Link to post
Share on other sites

Hey Vern, you keep mentioning the unmentionable. Even in mixed company, the four letter words keep coming.
The batteries are acting like they're running on surface charge only, with no depth to them. The only DC load on them is the house load, including the furnace. She ran the furnace the other night, with it coming on 3 or 4 times overnight. The next morning, the Magnum was in "DC Overload" lock-out, even though the battery voltage was 12.0v. After a quick application of the cheap external battery charger, the Magnum resumed it's Bulk charging duties, until the furnace cycled a couple times. I suspect these batteries have been abused in the past, as some minor bulging is showing on the ends. The owner doesn't remember when they were last replaced, as that was a "Blue" job, and he has passed.

Share this post


Link to post
Share on other sites

Darryl & Rita, FWIW just in case the batteries died (do you have a load tester handy) I recently replaced my Four Trojan T-105/s with two Renogy 12 Volt Size 4D AGM's giving me 416 total Amp Hours (20 Hr Rate)  comparable to the four Trojans 450 AH and so far love them. They were like $399 each on Renogys website but Walmart shipped them to a local store free for like $245 each.

John T    PS I just received my November Escapees Magazine late and to my total surprise there I am on Page 16 with my banjo in hand. 

Share this post


Link to post
Share on other sites

re: battery load testers. If memory serves me correctly, the load tester must have the capability (old ones were carbon pile) of at least half  battery total amperage capacity. One of the experts, please correct me it that is incorrect.

Share this post


Link to post
Share on other sites

To put this one to bed, after the owners returned from a cruise vacation, I killed all the power into the unit, pulled all the boards out and checked for more bad solder joints. This unit must have seen lots of use, in hot temps. Lots of suspicious solder joints, which were hit with a soldering iron to get good connections again. The boards should probably be replaced, as this isn't really a permanent solution, but rather, a method of troubleshooting. The charge side has been working flawlessly for the last week, in cool weather of Arizona. Owner to decide whether to send whole unit back for refurb ($850), or order the rest of the boards new.($2-250 per board, x 3)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

RVers Online University

campgroundviews.com

Our program provides accurate individual wheel weights for your RV, toad, and tow vehicle, and will help you trim the pounds if you need to.

Rv Share

Dish For My RV.

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.



×