does converter charge truck batteries

I had the same question a while back and ended up solving it by adding some hardware. Here is a link to the discussion: Link

This is a late reply, but I thought it might help out those Tioga 31m owners, and maybe a few other Tioga models. On my 2008 Tioga 31, which is really a 2007, the Bi-directional Isolator Relay Delay is under the top step, next to the double set of house batteries. I learned that my BIRD works perfectly. My house and chassis batteries get charged at the same time, whether on shore power, on generator, or engine.

The unit I use to maintain my engine battery, plugged into one of my motorhome's 120 volt AC outlets when in storage with the unit's output cable plugged into a cab 12 volt receptacle, is this one:

http://batteryminders.com/details.php?prod=12117

My prime reason for using this maintainer is to make sure that the chassis battery does not suffer from low-voltage sulphation that results from the high intrinsic leakage discharge rate of liquid acid batteries that are sitting around not being topped up by the engine alternator. To counter this continual leakage discharge only takes a small amount of continual replacement current, and this little maintainer does that with it's small ~1.0 amp average output current driven by it's automatically varying voltage levels. This small amount of current will not result in enough voltage drop, along the output cabling the came with it or the cabling size in cab 12 volt receptacles, to in any way compromise what it's doing.

Using this unit, my engine battery has no reason to ever need heavy-current charging except immediately after an engine start - in which case the alternator does the heavy lifting - or unless I were to leave something turned ON in the chassis systems when in storage that I shouldn't have.

With a too-low engine battery the engine can always still be started by temporarily boosting the engine starting battery with the coach batteries. I have a switch for this in the cab and the after-market heavy continuous duty solenoid I installed connecting all these batteries temporarily together has silver alloy contacts so it will never fail from ambient corrosion or electrical erosion of it's contacts. This same solenoid is also automatically held engaged when the engine is up and running so that both the engine battery and coach batteries are connected all together in parallel so as to be topped up and kept topped up by the alternator when traveling.

If both battery systems should ever be flat enough to not start the engine or built-in Onan generator, we carry a small portable manually started generator that can always breath life into any of the batteries.

Note that when traveling I have both the AGM coach batteries and liquid acid engine battery all hooked together in direct parallel being charged by the 130 amp engine alternator. The two balanced-parallel connected Group 29 12 volt wheel-chair AGM coach batteries are over 7 years old and still acting like the day they were new. The non-stock big Ford engine liquid acid battery is at least 5 years old and turns over the V10 in a flash even on cold mornings. I very, very rarely add any water to it ... way less than annually.

I'm kindof at a loss as to why the BIRD would be needed. The little maintenance units like I'm using are way less expensive and seem to offer more flexibility in how one can continually optimize RV coach and engine battery maintenance ... given that one has a motorhome with it's alternator and electrical systems set up in a certain way. I don't think my Winnebago-built motorhome came stock set up in an unusual way ... not counting the special inter-connect solenoid I used to replace the one that came in it.

Interesting that you brought that up. I know that on here there are a lot of battery wizards, so they may have some answers about different types of batteries and how they are charged. I have heard that doing it the way you suggest is not as efficient because the wires from the outlets in the cab are not big enough to transfer enough voltage back to the battery.

I know a person that has the BIRD in his rig and has the reverse of yours, he has a AGM type Chassis battery and 2 wet cell 6 Volt Trojan Coach batteries,with the same Progressive Dynamics multi stage charger/converter that I have. He has kept it plugged in 24/7 when not in use for the last 5 years with no problem at all. His batteries are in top shape and ready to go at anytime.

A problem I see with how the BIRD works is this: What if your coach batteries are a different type than your chassis battery?

My coach batteries are a special AGM type ("wheel chair" batteries) that are both charged and floated just fine by the stock single voltage Parallax converter that came in the RV, whether on the road or in storage.

My chassis battery is a starting battery using classic wet liquid acid technology, so I keep a small multi-stage charger ... that in addition has a unique desulphating stage ... connected to the chassis battery 24/7 whenever the RV is in storage. This is very easy to do since I keep the RV plugged in all the time during storage. I just plug the small multi-stage charger into one of the RV's 120 volt AC outlets and then plug the long output cable that came with it into one of the cab's 12 volt receptacles. This then keeps the chassis battery well maintained because the cab's 12 volt receptacles are still "hot" when the ignition if off ... hence I'm in effect back-feeding the small charger's output into the engine battery to maintain it. The engine battery is Ford's best so it has a 100 month warranty and I hope to get 100 months of life, or longer, out of it.

I could not do this with a BIRD device (... as I understand how they operate).

Thanks for the explanation IAMICHABOD.

Sounds like the OP should wait a few minutes after plugging in to check the chassis battery voltage.

tenbear wrote:

The BIRD may not start charging the coach battery until the voltage drops below some predefined level, so if the voltage does not increase it may not be definitive. I don't have experience with a BIRD.

This true It operates by sensing the voltages on both batteries.
When either of these voltages exceeds 13.3 volts for
approximately 1 minute, which happens when either battery
is being charged, the control will close the isolator solenoid,
connecting the two batteries together, charging them both.
(Normal charging voltages are from approximately 13.8 to
14.4 volts.)
After the solenoid has been closed, the system continues to
sense the voltage. If the ignition switch is off and the battery
voltage drops below 12.8 volts for approximately 1 minute,
which might occur when the converter is heavily loaded,
the solenoid is opened to prevent the chassis battery from
being discharged by the coach loads. When the voltage goes
above 13.3 volts again for approximately 1 minute, the solenoid
closes again. Thus always keeping the Coach as well as Chassis battery charged. Regardless of the parasitic draws on the chassis battery that run it down while sitting unused.

Our 2004 Tioga had no BIRD device. I added a Trik-L-Start, it keeps starting battery up when rig is plugged into shore power. I had to route a long #14 guage wire from the Trik-L-Start device, in the house battery compartment, underneath the rig, zip tied along the frame and up through the right fender, then through a 15 amp circuit breaker and finally to the starting battery positive terminal. Our rig did not have the type of relay device to connect to as mentioned in the Trik-L-Start directions.

To see if your converter charges your coach battery, measure your coach battery voltage with the motorhome unplugged. Then plug in the motorhome and measure the coach battery again. If the battery voltage increases when the MH is plugged in, the battery is being charged.

The BIRD may not start charging the coach battery until the voltage drops below some predefined level, so if the voltage does not increase it may not be definitive. I don't have experience with a BIRD.

IAMICHABOD,

I have a 2008 Tioga, Class C. Would this motorhome also have the BIRD?

Thx.