MOD New Aire Chassis Battery Charger / Maintainer

[MarkMaxPayne]

New Aires with factory Lithium have quite the reputation on draining chassis batteries if parked for just a couple days without turning off the battery disconnects. I have also heard of and read reports of others who have them die even when connected to 50A shore power. Well after 3 months plugged into shore power at an RV "resort" while between sticks and bricks as we sell our home and buy a new one, my chassis batteries got drained to the point they wouldn't hold a charge anymore.

After replacing the chassis batteries with AGMs, I stopped by NAPA Auto and picked up a 12V/10A battery charger/maintainer. Like others, I mounted in the Spartan's chassis battery compartment and used a heavy duty AC power cord wrapped in split loom routed to the engine heater outlet in the engine compartment.

Now, as the vampire drain(s) hit it, this maintainer will keep the chassis batteries charged instead of relying on SilverLeaf to join/bridge them to the house batteries and the inverter/chargers. So far so good. Fingers crossed.

Thanks for the prior posts on this workaround to this frustrating issue.

Best,
-Mark

 

[MemoriesByTheMile]

We did this on our Renegade coach. One less item to worry about now.

 

[lostinfla]

I'm a little confused as to why this is happening. In almost 10 years now, our DS has never drained the chassis batteries while plugged in, which is 99% of the time when not driving. Our coach does not have Silverleaf, is that the issue?

 

[Joe Hogan]

In my opinion it sounds similar to our issue with a bad DIP/BIRD solenoid.
Or potential bad charging circuit

 

[Joe Hogan]

Newmar still seems unsure how to make the LiPo house battery option perform without some issue.

 

[Richpatty]

I have not seen this issue…my chassis batteries stay charged while on shore power using the LiBim.

Can you monitor the chassis batteries from one of the consoles in the RV? Can you see that it is declining over time?

 

[MarkMaxPayne]

Can you monitor the chassis batteries from one of the consoles in the RV? Can you see that it is declining over time?

Yes, with the new batteries installed on the SilerLeaf panel I was able to watch the chassis battery voltage drop over time in 0.1V increments even though plugged in to shore power. Each day, the charge was less... Once it dropped low enough the word "bridged" would light up on the SilverLeaf, they would charge, but they would not charge back up all the way before it unbridged them again. Basically a ramped down sawtooth until fully drained. I only watched this for 2 days on the new AGM batteries before my run to NAPA Auto Parts.

On my rig, and apparently some others as well, having a dedicated charger/maintainer while plugged into 120V shore power bypassed the SilverLeaf needing to try to join them to charge/maintain them. When the engine is running the alternator still charges them.

Best,
-Mark

 

[CaptainGizmo]

Food for thought…

My friend, who is a EXTREMELY technical high-end electronics engineer, had to battle a lot of issues after converting his house AGMs to Lithiums. Reason being, the Outback chargers couldn’t handle two entirely different battery chemistry’s charging profile.

As you know, Lithiums can have different voltages in addition to vastly different charging profiles. So, he had to do a lot with a Victron SmartShunt and, eventually, having a dual Victron inverter system was the way to go.

For our coach, I immediately separated my chassis and house charging by using separate external chargers. The house batteries are dual series banks so I had a nice pigtail quick-connect made that is pre-connected to the near and far terminals. Been great…and never have to rely upon the Merge switch.

 

[Richpatty]

Yes, with the new batteries installed on the SilerLeaf panel I was able to watch the chassis battery voltage drop over time in 0.1V increments even though plugged in to shore power. Each day, the charge was less... Once it dropped low enough the word "bridged" would light up on the SilverLeaf, they would charge, but they would not charge back up all the way before it unbridged them again. Basically a ramped down sawtooth until fully drained. I only watched this for 2 days on the new AGM batteries before my run to NAPA Auto Parts.

On my rig, and apparently some others as well, having a dedicated charger/maintainer while plugged into 120V shore power bypassed the SilverLeaf needing to try to join them to charge/maintain them. When the engine is running the alternator still charges them.

Best,
-Mark

Gotcha…I don’t have Silverleaf, but the precision circuits display…which is much more basic and easy to see. If I have an issue, it is with the LiBIM connecting the banks together and not letting go…which could overcharge the house batteries, which do not need such a high voltage.