Dead Auxiliary Batteries

jefe · Post by **jefe** » Tue May 06, 2014 9:07 pm

Forgive me if this is mundane, but we're first time RV'ers and brand new BF owners. We recently bought a 2005 26' RSB and drove it back to NC from Houston Tx. Everything worked well when we picked it up and during the trip; however, after leaving the rig unplugged overnight when we got home, we woke to find both auxiliary batteries dead. They charged well when plugged in but died again the next night, again, unplugged. The first night we did not switch off the knob next to the entry stairs marked "fully engaged at detents" but we did the second night. Is there something we need to do to "disconnect" the batteries before storage to prevent leak or is there something faulty with our electrical system? Thanks for any help!

jefe · Post by **jefe** » Tue May 06, 2014 9:32 pm

Sam Ryan wrote:A discharge of this nature may be caused by very low water in the batteries.

Thanks, I will check this. I should also note that although I did not purchase the batteries, they are dated 9/13 so I believe they should still be in good condition.

Edit: Kudos Sam, batteries were not bone dry but definitely low. Will refill when I can get some distilled water and update on results. Thanks!

whemme · Post by **whemme** » Tue May 06, 2014 9:49 pm

Jeff,

Sam is right about possible low water in your batteries. Also, it is possible to destroy new batteries in only 6 months if they have been low on water for some time or have been left in a totally discharged status for some time.

Your Born Free should have a Parallax 7345 Charger/Converter system in it. If your coach batteries are nearly fully discharged but otherwise in good condition, it will take the 7345 charger 72 hours to bring the batteries up to the 90% charge level either being plugged into shoreline power or running your generator for that long time. Driving your coach will recharge your batteries much faster using the engines alternator.

To see if your 7345 charger is working properly, when plugged in to shoreline power and using an accurate DC voltmeter across the battery's - and + terminals, you should see a charge voltage of +13.6 to +13.8 vdc. Next unplug from shoreline power and start the coach's engine. The charge voltage then should be higher in the range of +14.2 to 14.4 vdc. If both of these charge voltages check out OK, then if your coach batteries still won't hold a charge, barring some unknown serious drain on the batteries, I would suspect your almost new batteries may be toast.

bcope01 · Post by **bcope01** » Tue May 06, 2014 9:57 pm

You might want to search previous posts on this forum if you have the OEM Magnetek/Parallax converter/charger in your coach. They are reknown for overcharging the batteries and evaporating all the water out of them, resulting in ruined batteries that won't hold a charge (happened to me). Many of us have replaced that OEM converter/charger with a "smart" 3 or 4-stage converter/charger.

Bill

cmeadows · Post by **cmeadows** » Wed May 07, 2014 12:39 am

Jeff & Meg

As Bill Cope has already suggested, there is a worthy upgrade for your coach. Bill Hemme posted excellent information on the topic to save your batteries:

“Converting Parallax 7345 Charger/Converter to PD4655 system”
http://www.bornfreervclub.org/bulletin_ ... php?t=2482

This is a link to the product (available from many other sources):
Progressive Dynamics (PD4655V) 55 Amp Converter/Charger with Built-In Charge Wizard
http://www.amazon.com/Progressive-Dynam ... 002OR4242/

This was the first change I made to our coach after we purchased it used a couple years ago. I installed the kit including the new circuit board and gained 3 additional fused DC circuits. We leave our coach plugged-in during storage and this unit keeps the batteries charged while preventing overcharging.

al1florida · Post by **al1florida** » Wed May 07, 2014 6:12 am

"Low Water" in the battery, I believe, means that the plates are exposed to the air, not that the water is lower than normal.

As long as the plates were not exposed when you looked to see how much water was in the batteries that should not have been the cause.

If the previous owner left the coach unplugged for a long time, 3-6 months that could have totally drained the batteries.

The previous suggestions on diagnostics are right on the money.

jefe · Post by **jefe** » Wed May 07, 2014 6:28 pm

Just thought I'd post an update since all of you were so kind to reply and provide lots of great help. We're thrilled to be BF owners knowing such a wonderful community comes with the rig.

About half of the battery 'tanks' were quite empty leaving rods exposed to air. (It took an entire gallon of distilled water to fill both batteries) I did know about the need to 'water' a battery but at the time it occurred to me I didn't have anything to pry open the lids and when I saw the recent purchase date I dismissed that as a potential problem. What I didn't know was what the Bills Sam and Chuck pointed out about the converter. It is, in fact, a Magnetek/Parallex converter so I'll probably look into replacing this.

Batteries have started charging, I'll probably give them ~72hrs to fill up as some have recommended here to fully charge before testing their hold.

Thanks again!

whemme · Post by **whemme** » Wed May 07, 2014 9:11 pm

Jeff,

If it took a whole gallon of distilled water to bring the water level in each cell up to the slot in the bottom of the fill hole and if your batteries have been low by that amount for several months, quite likely the batteries have been damaged by this.

jefe · Post by **jefe** » Wed May 07, 2014 9:25 pm

whemme wrote:Jeff,

If it took a whole gallon of distilled water to bring the water level in each cell up to the slot in the bottom of the fill hole and if your batteries have been low by that amount for several months, quite likely the batteries have been damaged by this.

I'm a little worried about this. Only the tops of the plates were showing/exposed but they did take a lot of water. Time will tell I guess. I may see about possible warranty coverage.

Ray · Post by **Ray** » Wed May 07, 2014 9:57 pm

Dont tell them the water was low - no battery warranty will cover that

Rob · Post by **Rob** » Tue May 13, 2014 11:34 am

I just purchased 2 Trojan 6 volt T105's to replace my dead Interstate batteries.
Bill's excellent post here is good advice. After installation I plugged in to shore power thinking that the Parallax 7345 would bring them to charged in a day. Of course not. My question is will traveling about 200 miles with the alternator bring them up to close to the 90%?

Rob and Joan Beery
2003 24RB

shilohdad · Post by **shilohdad** » Tue May 13, 2014 1:11 pm

We bought new Interstate batteries in early April (batteries manufactured in February, so pretty new). Meter read 11.8 volts, so fairly discharged. Drove home about 30 miles - did not get much charge.

Plugged in for 8 hours, got to maybe 12.0 volts (we had not realized how slow the charge was on shore power). Exercised generator 2 hours, again not much change (still ignorant about slowness of charge).

Checked water levels - OK.

Decided to risk a long weekend. Drove about 500 miles round trip. Did not check voltage until we got back. We turned battery off about 1 hour after returning home. I decided to check voltage about 3 days later. It was 12.6 volts, which we believe is a full charge (if not, would someone please chime in). The meter we used is one you stick in one of the 12 volt outlets, so don't know how accurate that is.

So, 500 miles and about 10 hours of driving seems to be enough. Is 200 miles enough? Maybe.

whemme · Post by **whemme** » Tue May 13, 2014 5:26 pm

Joe & Rob,

You can read a post of mine titled Coach Battery Charge Level Determination in the section titled Technical Library to learn how to know what charge level your batteries are at. It takes 72 hours (3 days) for your Parallax 7345 Charger/Converter to bring discharged batteries up to the 90% level. If you install a Progressive Dynamics PD4655 replacement charger/converter, it will do the recharge job in only 3 hours.

I would estimate that driving your coach a distance of 150 miles would also accomplish the recharge job to the 90% level.

Rob · Post by **Rob** » Tue May 13, 2014 5:32 pm

Bill,
Thank you so much. You are always so helpful.

Rob and Joan Beery
2003 24RB

jefe · Post by **jefe** » Wed May 14, 2014 6:24 pm

Well I charged them for 3 days then left it unplugged for a couple nights and they're dead again. I didn't turn the "kill switch" near the steps on to disconnect but I still don't think it should have drained them that quickly with nothing in the coach on. I may need to see about new batteries. I'm also thinking about replacing the parallax with the progressive dynamics that was recommended. Is this something I can do myself? I've managed to change brake pads, a garbage disposal and various computer component repairs without much trouble. Is there a walk through anywhere? Thanks again for all the help.

I assume I need to fully charge the batteries again and get a voltage reading on them before giving up? Or can I assume that if they die that quickly, they're toast?