Chassis Battery Recharging off the converter

[JavaJelly]

I was under the assumption that having my rig plugged in would keep my chassis batteries topped off.

However, I read an article in Motorhome Magazine that said unless you have a three stage converter then the batteries will not be charged correctly or completely.

My house batteries are charged in three stages, bulk, trickle (real name escapes me) and float charging but, wasn't sure if this crossed over into the chassis batteries.

I also noticed that now my coach has been sitting for a while that the voltage is sticking down aroun 12 vs. 13 - 13.8.

Finally, per the article, it said I needed to run the coach every month or so to keep them topped off. I know idling is not recommended for the powertrain so I wouldn't want to just start it to charge the batteries.

Anyone have any insight, or should I stop reading Motorhome Magazine.

[JavaJelly]

I was under the assumption that having my rig plugged in would keep my chassis batteries topped off.

However, I read an article in Motorhome Magazine that said unless you have a three stage converter then the batteries will not be charged correctly or completely.

My house batteries are charged in three stages, bulk, trickle (real name escapes me) and float charging but, wasn't sure if this crossed over into the chassis batteries.

I also noticed that now my coach has been sitting for a while that the voltage is sticking down aroun 12 vs. 13 - 13.8.

Finally, per the article, it said I needed to run the coach every month or so to keep them topped off. I know idling is not recommended for the powertrain so I wouldn't want to just start it to charge the batteries.

Anyone have any insight, or should I stop reading Motorhome Magazine.

[adj]

You probably have the same set-up I have; which is, the converter does not charge the chassis battery.

I keep an eye on my chassis battery voltage and when it reaches the 12V level, I put a charger on it to bring it back up to full charge.

I expect you will hear from other members about a "battery minder" set-up.

[edgray]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">wasn't sure if this crossed over into the chassis batteries. </div></BLOCKQUOTE>
JJ: your DSDP probably has an Intellitec Bi-Directional relay which, if present, serves to isolate the coach battys from the chassis battys (to prevent drawing down chassis batty while boondocking) but which ALLOWS the converter to charge the chassis when plugged in to shore, after charging the house battys to near full. Newmar installs them on "most" coaches.

That said, RVUpgrades sells a fool-proof way to insure your chassis battys are always ready. Go HERE to read all about them. ED

[Pusherman]

Don't know about Newmar, but Winnie began making a battery minder (Trik-L-Start) standard equipment beginning with the 2006 model year. It's intended to maintain the engine battery while plugged into AC. It's only a 5A charger.

Motorhome mag is correct relative to actually fully charging up the battery thru driving it.

Here's some info on Trik-L-Start.

[Kazoo Tom]

If your unit is not set up with the bi-directional relay, then Battery Minder or Trik-L-Start will do the trick for you. Both will keep your chassis battery up when you are plugged in, or when running the generator. I have installed a Trik-L-Start in mine and have been very pleased with the results.

[Petro]

I also use the Trik-L-Start and I have been very happy with it.

Don

[Jestme13]

I to have bought and installed the trik-l-start after FLCC told me to expect 2 to 3 wks before batteries go dead.

[hamdave]

My understanding is the converter does not normally charge the chassis batt. I installed a 20 amp fused circuit to allow me to do this through a spst switch. When I'm parked and on shore power, I simply close the switch. If there were a big difference in the batt's charges, it would be possible to 'pop' a fuse, but it seems to work just fine. I make sure the switch is 'open' when I start the engine. I have an 'aux' switch if I need to put the batt's in parallel to start engine. I have a 454 with TBI.

[Gary RVRoamer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">My understanding is the converter does not normally charge the chassis batt. </div></BLOCKQUOTE>
There is no "normal" to this question - it depends on the individual coach make & model and how the system was designed. Some provide for chassis battery charging and others do not.

To set the record straight, chassis battery charging does not require a three stage charger - just a battery isolation system that is smart enough to connect the chassis battery for charging when needed. The most commonly used smart isolator/relay is from Intellitec and their design requires at least 13.3V on the house batteries before it will connect the chassis batteries into the charging system. If the house batteries are in poor condition (or low on water) the charger may not be able to get the voltage high enough to allow the Intellitec relay to begin charging the chassis batteries. Other makes of battery controller may use a different charge level to make the decision, but it is probably close to that voltage.

You can always add jumper wires/cables to the chassis battery terminal while parked for extended periods, but be aware that this will also allow the chassis battery(s) to be discharged by the demand of the house 12V system if shore power goes off for some reason. For that reason it is best not to permanently wire a charging jumper.

[edgray]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The most commonly used smart isolator/relay is from Intellitec and their design requires at least 13.3V on the house batteries before it will connect the chassis batteries into the charging system. </div></BLOCKQUOTE>
Thank you, Gary. That is what I was trying to say. ED

[dieselclacker]

I have been using a $9.95 battery maintainer/trickle charger from Walmart for over three years. I added 110V plug to front compartment where it is located on motorhome, and ran wires directly to chassis battery. Have had no problems.

Dieselclacker

[hamdave]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You can always add jumper wires/cables to the chassis battery terminal while parked for extended periods, but be aware that this will also allow the chassis battery(s) to be discharged by the demand of the house 12V system if shore power goes off for some reason. For that reason it is best not to permanently wire a charging jumper. </div></BLOCKQUOTE>

I don't disagree with this and did not imply that I did. I simply have a method to switch in the chassis to the house charging system. My choice, my opinion.

[tom wilson]

my 1996 kountrystar has the bird that connects the house batteries to the chassis batteries when the motorhome is plugged into 120 volts. just look in the electrical compartment for bi-directional relay and follow the wires to a heavy relay with 2 battery cables connected to it. you can read the voltage of the house batteries and the chassis batteries. if the voltage is not the same when you are plugged in then you have a malfunction in the bird or the relay. my relay is white-rodgers continuous duty