Community Forums

AttilaKara72 · 11-19-2022, 03:37 PM

I keep my 1999 Monaco Windsor plugged into shore power all winter to keep the house batteries trickle chargered. I was wondering is there a way to connect the engine battery to keep it topped off also? Can I run some jumper wires from the house batteries to the engine battery.
Thanks in advance.

Jon_C · 11-19-2022, 05:58 PM

Yes you can jumper them together, as long as all are the same type, thats what most rv’s come with, a solenoid that ties both banks together when charging voltage detected.

This is something you can add fairly easily, just need to connect the positive as the negative side is already connected.

If you have lithium house youll have to use a separate charger for lead acid on the chassis bank.

Iceclimber · 11-19-2022, 07:12 PM

I recommend a VSR = voltage sensing relay. It senses charge voltage from either direction meaning your alternator or charger/inverter and it charges everything all the time. Those old solenoids, birds whatever they are called are outdated. The only caveat with my VSR is I no longer have the "battery boost" switch at the driver's seat. So, if I need to boost chassis with house batteries I have to walk back and push the button. If my chassis batteries are dead, I want my head in there any way to see what the deal is. Since installing, I have has zero issues with battery charging. I would not mess around with jumping cables, that is asking for a mistake.
https://www.amazon.com/gp/buyagain/r...NTTFLIn0%3D%0A

This particular one is likely not robust enough for the boost feature, meaning 140 amps can be easily be overrun by an engine start, but I still have inner peace.

YC1 · 11-20-2022, 05:58 AM

A jumper will do but as suggested, can be hazardous. One spark inside a battery compartment can end in disaster. The battery compartment should be well-ventilated before installing or removing a jumper.

As mentioned there are many inexpensive options for adding a device to work permanently. Yandina makes some neat tricks, amp-l-start is another that is often suggested here.

twinboat · 11-20-2022, 06:02 AM

Do you have a Lambert le-45 or similar in your battery control center ?

It's job is to maintain the chassis battery when the house batteries are charging.

153stars · 11-20-2022, 03:05 PM

Bad thing about jumped together if you drain one set drain both.
The Lambert maintainer mentioned has green heatsink and will cycle \click on and off, if chassis batts pull over 15amps to prevent overheating.
Several of us have installed Bluesea MLT-ACR it can replace boost solenoid, Lambert charger and diode isolator. Provides bidirectional charging, house from alternator and chassis off the charger. Down side is need to run a few extra wires to dash. Several threads pics and diagrams. Many do it after boost solenoid failed .

Snokid · 11-20-2022, 08:28 PM

when my b.i.r.d. relay module went bad I bought a small battery charger from walmart hooked it up to chassis batteries presto stayed charged till I got it fixed. But seems something went bad on my last trip the relays not working again!!! going to break out my small charger again till I have time to get to the relay again.... always something....

Randalpho · 11-21-2022, 11:05 AM

Can you read the voltage on the engine battery at rest? If it's above 12.6 then it's being charged with the house batteries.

Flyer15015 · 11-21-2022, 11:36 AM

OP,
Why not use 2 Battery Tender trickle chargers ?
When I park the coach in the barn for the winter, I just hit the salesman's switches and attach a tender to the coach and another to the chassis battery.
Come back 3 months later and all is fine.

Mike in Colorado

tc914-8 · 11-29-2022, 02:06 PM

Quote:

Originally Posted by Flyer15015

OP,
Why not use 2 Battery Tender trickle chargers ?
When I park the coach in the barn for the winter, I just hit the salesman's switches and attach a tender to the coach and another to the chassis battery.
Come back 3 months later and all is fine.

Mike in Colorado

I agree, I let my house batteries charge on the inverter/converter and I have a separate battery tender for my chassis batteries it’s been working fine for many years now.

8.3Oilbuner · 11-29-2022, 02:57 PM

Hi AttilaKara72; As Twinboat mentioned, do you have the Lampert Le45 battery maintainer? I have one in my 01 Windsor and it keeps the house and the chassis batteries charged. Also was equipped on my previous 2000 Windsor. Worked great!

botiemad · 11-30-2022, 06:18 AM

The best, and safest answer is to install a combiner. It will float both banks at the highest level of charge possible, and automatically disconnect either bank if a battery in that bank has a problem. Magnum makes a nice unit. The 3 wire install takes just a few minutes to accomplish.

lpsfu48 · 11-30-2022, 07:58 AM

Quote:

Originally Posted by AttilaKara72

I keep my 1999 Monaco Windsor plugged into shore power all winter to keep the house batteries trickle chargered. I was wondering is there a way to connect the engine battery to keep it topped off also? Can I run some jumper wires from the house batteries to the engine battery.
Thanks in advance.

Just a thought : I have two solar panels on my 2001 Monaco Diplomat. I also have eight house batteries in two packs in the rear two battery compartments along with the engine batteries. I charge the whole works with my solar panels without plugging in. I have a series of connecting wires that use the solar panels wiring coming down beside the fridge and travelling to the battery packs. I also use a switch to separate the rear 4 battery pack from the rest, so I can use the rear pack as a reserve. I have pictures of the works but have to dig for them. You can definitely benefit from this but if you are cramped for space and don’t want to use this method; You can definitely join in your engine batteries to take advantage of the charging process.