Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 11, 2025 ...

Chassis Battery charging while stored

October 04, 2018, 12:46:59 am

We have an occasion, to leave our coach for about 3 weeks. Thinking about a temporary way to charge the chassis battery's with my solar. Thinking about a # 10 with a 30a fuse from the hose side of the battery to the start battery. Or just temporarily move the chassis battery cable to the house stud on the isolator. The coach will be move about for repair then parked plugged in for 3 weeks or so.

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Re: Chassis Battery charging while stored

Reply #1 – October 04, 2018, 01:30:04 am

Why not just put a jumper between the house and chassis battery at the isolator as a temporary measure? You could fuse the jumper wire if you wanted to, but I would think a 10 amp fuse would be sufficient, especially if the house batteries are close to fully charged. Of course, if you will be starting it often while a jumper is in place, it would be kind of a pain to have to open the bed and disconnect it...
Don

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Reply #2 – October 04, 2018, 02:32:03 am

Or simply disconnect the negative cable to the chassis battery. It will easily hold charge well longer than three weeks.

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Reply #3 – October 04, 2018, 06:45:38 am

I agree disconnecting the negative would allow battery to not lose too much.
Another way is to get a Trip-L-Start Ultra TRIK-L-START Starting Battery Charger/Maintainer
or similar device, which would divert some charging to the starting batteries.
This would work if your solar panels produce enough.

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Reply #4 – October 04, 2018, 07:09:58 am

I agree with Eric on the Trip-L-Start. I installed the larger Amp-L-Start several weeks ago, my chassis battery has never been happier. Planning on putting temporary solar panels  to charge the house & start batteries when she goes back into storage.

Larry

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Reply #5 – October 04, 2018, 09:39:47 am

Thank for the replies. The coach will be at MOT for repairs then stored there for a couple of weeks plugged in. I would imagine I could get them to pull the ground cable, I doubt they will install any jumper.

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Reply #6 – October 04, 2018, 12:00:40 pm

Or,  have them install a ground disconnect.

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Reply #7 – October 04, 2018, 12:35:04 pm

I use solar to charge house, with redundant trim l starts to maintain chassis off the house bank Two because I have had one fail and ruin a set of chassis red tops Also has a battery minder 1500 on chassis bank that only is active when shore power preset I know. Overkill

Tim Fiedler
Gen-Pro.biz
630 240-9139

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Reply #8 – October 04, 2018, 01:08:54 pm

Any temp can be problematic.  Only sure way to stop killing $700 of red tops is to bite the  bullet and install an auto battery combiner.  Like all the new coaches have.

You already have the input from solar or shore power it seems,

I am too critical on batteries.  Once damaged from discharge I install new ones.  Better to buy the combiner IMO.

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Reply #9 – October 04, 2018, 02:06:44 pm

Bob

Are you suggesting the output of a trik  start or battery minder 1500 can damage redcaps from overcharging especially at higher ambient temps?

Batteyrminder is temp compensated, albeit unless a separate temp senser is in battery compartment it picks up the temp at the charger not the battery which can be some distance away. Just seems like output is so low and they both go into float when fully charged, hard to see how they could overcharge/over temp the red tops, but I am far less than an expert on this topic.

So far, has worked great for me

Tim Fiedler

Sure Start Soft Start - home of SureStart soft starters TCER Direct - home of Generac Approved Aluminum and Copper TCER Composite cable generator-gas-prod - home of X-Riser Gas Risers for PE installation Call me at 630 240-9139
Gen-Pro

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Reply #10 – October 04, 2018, 03:38:08 pm

My trickl charger failed internally.  Green light on.  No output.

The solar/ combiner is  bullet proof. 

I have had shore powers breakers open in strings because of am overload or a voltage surge before.

For sure the auto combiner and solar will work regardless.

all the new coaches come this way for a reason 

Even plugged in if someone opens the breaker in 3 weeks you will need new engine batteries.

How to lessen the variables is my goal.  We are preppers and being totally self contained in storage is needed.

The profile on the auto combiner keeps  banks basically at float continuously connected to a nominally 13.6 volt solar system

System lessens mistakes if left in auto.  Cannot forget, 

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Reply #11 – October 04, 2018, 04:46:44 pm

Hi Bruce. Hope all is well. Just jumper the house and chassis battery. No fuse required. Think of it as a boost switch that's always on, but without the power demand of the boost solenoid. Simple. If both batteries are of lead acid technology, the solar system would charge both and keep them at 100% SOC, where they belong.

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Reply #12 – October 04, 2018, 05:05:24 pm

Tim,

The fuse is to prevent the WIRE used for the jumper from overheating and causing a fire.  Were one battery to be deeply discharged and the other at a higher state of charge, you don't want amperage (and therefore heat) to turn that wire into a RESISTANCE HEATER.

Also, I have seen people use alligator clips on these.  OK while parked, but never leave them on while you are moving-- too easy for one end to "jump off" and contact body/chassis metal which will be a dead short.

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Reply #13 – October 04, 2018, 06:32:39 pm

I do intend to install an ACR that's a project for another day. I talked to James they will pull the ground cable.

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Reply #14 – October 04, 2018, 10:26:17 pm

Bruce- talk to James about a VSR ( Voltage Sensing Relay).  It will sense charing the house batteries and send some current to the chassis batteries to keep them up.  It automatically shuts off at certain prescribed levels which I don't remember now but James can explain it to you.  I had one put on at MOT. 

Good luck                   

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Reply #15 – October 04, 2018, 10:29:53 pm

Google Express
Mounted mine right above isolator, two short wires and a ground.

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Reply #16 – October 04, 2018, 11:34:38 pm

Not that it matters much, good, bad or otherwise my smart isolator??? Appears to sense engine start battery voltage and charge it first priority, then switches any 12 v output back to the house batteries. Plugged in or on the generator, engine start battery is ready to rock n roll via a four stage convertor/smart charger???. Maybe I am missing something that will leave me dead on the side of the road, as I'm not by any means an electrical guru. IRC that 150 amp Cole hersche unit was about $130.

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Reply #17 – October 05, 2018, 04:56:11 am

Jump the house and chassis batteries with a 2/00 cable. No melting of wires. Simple. No down side.
Upside: Your expensive engine batteries will get exercised and, if they are flooded, will get:

- Topped off
- Equalization:
If the battery remains in the 'Float' state for seven days, your solar charger should cycle to dissolve sulfate layers and avoid stratification of the battery

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Reply #18 – October 06, 2018, 12:06:14 pm

So temporary fix I have a #l gauge cable jump the 2 terminals on the isolator. Boost sw still works, not enough start load on the cable to matter?

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