1993 Safari Serengeti driving batteries going dead

[canucklehead]

My driving batteries to start the diesel engine are getting drained down when unit sits for a week or so. nothing obvious I can see. Maybe memory wire for radio stays hot but can't think of what else would cause this or draw on batts when not running. Newer batteries. I noticed a couple of RV solenoids/battery isolators. I believe they have 2 big posts and one small post in middle. Middle/small post should be ignition controlled so when coach running, the batteries can get charged but when ignition off, the isolator should kill power to battery so the coach doesn't drain it down. I have not checked these isolators. wondering if they are prone to fail and if anything else I should look for that might drain these.

[ocmikeb]

Not sure if they are the same but my 2002 Zanzibar was doing the same thing until I found out that the automatic entry step was draining the start batteries. There is current on the step all the time. I installed a 300 amp disconnect switch on the negative side of the batteries. Have not had a problem since.

[fourbrrl]

My 95 sahara would kill the chassis batteries while nothing attached to positive post ( like stair power) even with the main chassis switch off. The inverter would charge the house batteries when plugged to shore, but not the chassis batteries. Even if i left chassis switch on. With chassis on, the chassis batteries would go flat rapidly. I installed a smart battery isolator in place of the original isolator, moved the alternator charge wire to chassis battery, turned chassis master disconnect switch on, now the inverter charges house and chassis as needed when plugged to shore or driving with alternator charging. It automatically switches between the 2 separate battery sets based on voltage. amazo has a 140 amp smart isolator for 30-40 bucks..!!

[TDJohn]

Chassis batteries to have various drains on them, including the Allison computer, and other things already mentioned. If the chassis batteries discharge rapidly, it is possible that a switch like "heated mirrors" or basement lights was accidentally turned on. It is also possible, that after having new batteries installed, a wire that belonged on the house battery bank got accidentally placed on the chassis battery bank, causing the rapid drain on the batteries.

[canucklehead]

my friend I bought this from had installed a disconnect at chassis batts but it is a bit of a PITA to lift bed all the time with the dead bed lift struts and use a stick to prop open..wondering if stick will wiggle and bed slam down on head . I actually have a pair of Ford truck hood struts...maybe i should replace and wont seem as bad to just disconnect there.

fourbrrl, your fix sounds interesting but i do have long periods of park/no use so would chassis batts still be drawing down if no shore plugged in?

[chuckster]

The disco switch is good to have for long periods of park with not plugging in but, if like myself) you keep your coach plugged in but you do not want to have to start the engine occasionally, check out an AmplStart. It will bleed off just a tad of house batterie to the chassis batteries and only when needed at the amount of current needed. Works great for me where my coach stays plugged in my garage but i don't want to start the coach once or twice per month. Would work the same plugged into campground shore power for longer periods of time with no starting the engine to keep chassis battery maintained. There IS something to be said about an occasional engine starts to keep everything lubed for longer periods of time.

https://www.rvupgradestore.com/15-Amp-S ... -start.htm
Buy

https://www.youtube.com/watch?v=UhO206nrLoo
YouTube review

https://www.irv2.com/forums/f84/amp-l-s ... 05404.html
IRV2 forum chat

[fourbrrl]

my friend I bought this from had installed a disconnect at chassis batts but it is a bit of a PITA to lift bed all the time with the dead bed lift struts and use a stick to prop open..wondering if stick will wiggle and bed slam down on head . I actually have a pair of Ford truck hood struts...maybe i should replace and wont seem as bad to just disconnect there.

fourbrrl, your fix sounds interesting but i do have long periods of park/no use so would chassis batts still be drawing down if no shore plugged in?

The smart battery isolator will shut the discharged battery off ( I do not see how that is possible being that it just switches the charging between batteries based on sensed voltage). If parked I use an adapter for 50 amp service plug to 3 prong extension cord and leave it plugged to an outlet just for the inverter charger.
I am still working the few bugs out of mine in order to make it turn key and go.
I had been fighting chassis battery discharge for a while now, I even used a thermal imaging camera on the batteries, saw ZERO heat signatures. The chassis batteries are december 2022 replacements, test excellent. The smart isolator made sense once I wrapped my head around what it was doing. The later coaches have a massive relay thats circuit board controlled that does this.