Engine battery dead even when plugged in

Forum for both AC and DC electrical components. From engine alternator to dashboard, inverter to batteries, and everything electrical in-between.
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Engine battery dead even when plugged in

Post by chuckster »

Hi SFriends,

I went to start up the coach today and engine battery was dead and the CO2 sensor beeping away even though coach was plugged into the garage 50A. I was under the assumption that the electronics that kept the house batteries charged did the same to the engine battery. Not so?

I was able to use the switch on the dash to jump the house battery and engine battery to get the coach started. I’ll be checking water levels in all the batteries today. Wondering how I find my battery drain problem if the battery is in decent shape.

Chuck
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
05wingrider
Posts: 104
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Re: Engine battery dead even when plugged in

Post by 05wingrider »

Chuck,
I'm not totally certain about the newer rigs (mine's a 96), but our Engine Batteries aren't normally part of the Inverter/Charger circuits - it only does the House batteries. I put a trickle charger on my engine batteries for just that reason after running a power lead into my maintenance bay from one of my "non-inverter" circuits in my main panel. As far as your CO2 sensor goes, I'm not sure why it would be beeping unless it was wired into the engine battery circuit (which would kind of make sense in some regards because you always have a good battery there versus the house ones can be drawn down and then you wouldn't have that mode of protection). Perhaps someone with better knowledge of that circuit system will chime in. Also - be aware that the original sensors were only designed to last 10 years, so the beeping could be it's way of telling you that the lifespan on it has expired. I unhooked the original hard wired one in my rig and put 2 battery ones in instead because of the age factor.
Duane
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
ProCycle
Posts: 135
Joined: Sat Oct 03, 2020 1:28 pm

Re: Engine battery dead even when plugged in

Post by ProCycle »

The chassis batteries do not charge when plugged in.
I suggest getting one of these --> https://amsolar.com/rv-battery-accessories/98-trikl
It trickle charges the chassis batteries from the house batteries. As long as the house batteries are being kept up the chassis batteries will too.

I believe the CO sensor is typically run from the chassis batteries. It could certainly drain the batteries over an extended period.
Jeff
1997 Ivory Edition 3740 Cat 3126 Allison
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Re: Engine battery dead even when plugged in

Post by chuckster »

05wingrider wrote: Sat Feb 20, 2021 11:33 am Chuck,
I'm not totally certain about the newer rigs (mine's a 96), but our Engine Batteries aren't normally part of the Inverter/Charger circuits - it only does the House batteries. I put a trickle charger on my engine batteries for just that reason after running a power lead into my maintenance bay from one of my "non-inverter" circuits in my main panel. As far as your CO2 sensor goes, I'm not sure why it would be beeping unless it was wired into the engine battery circuit (which would kind of make sense in some regards because you always have a good battery there versus the house ones can be drawn down and then you wouldn't have that mode of protection). Perhaps someone with better knowledge of that circuit system will chime in. Also - be aware that the original sensors were only designed to last 10 years, so the beeping could be it's way of telling you that the lifespan on it has expired. I unhooked the original hard wired one in my rig and put 2 battery ones in instead because of the age factor.
Duane,

Makes sense I suppose that the inverter/charger and the chassis are not both charged from that system.
I have a newer CO2 sensor mounted on the ceiling of the bedroom. As soon as I hooked up a trickle charger to the chassis batteries the beeping stopped immediately. Probably a safety feature to let you know that power is too low for accuracy of the sensor...I don’t know. In any event the coach is now 20 this year so the CO2 sensor is likely only good for letting me know I have a low chassis battery. I guess if the coach is going to sit for a few months I either need to start it up and run down the road for a few miles and back or keep it on a marine trickle charger.

Regards,
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Re: Engine battery dead even when plugged in

Post by chuckster »

ProCycle wrote: Sat Feb 20, 2021 11:40 am The chassis batteries do not charge when plugged in.
I suggest getting one of these --> https://amsolar.com/rv-battery-accessories/98-trikl
It trickle charges the chassis batteries from the house batteries. As long as the house batteries are being kept up the chassis batteries will too.

I believe the CO sensor is typically run from the chassis batteries. It could certainly drain the batteries over an extended period.
Hi Jeff,

Thanks for the link!

Regards,
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Engine battery dead even when plugged in

Post by TDJohn »

chuckster wrote: Sat Feb 20, 2021 10:42 am Hi SFriends,

I went to start up the coach today and engine battery was dead and the CO2 sensor beeping away even though coach was plugged into the garage 50A. I was under the assumption that the electronics that kept the house batteries charged did the same to the engine battery. Not so?

I was able to use the switch on the dash to jump the house battery and engine battery to get the coach started. I’ll be checking water levels in all the batteries today. Wondering how I find my battery drain problem if the battery is in decent shape.

Chuck
Chuck,

Usually the newer Safaris like your vintage included an echo charger (google it to see what they look like). It would likely be located in the engine compartment or the battery compartment. Check the input and output fuses, one of them could be blown, negating the function of the echo charger.

BTW, if you plan to do a lot of boondocking in the future, echo chargers are not ideal for that purpose, as they suck of the chassis batteries. For the ones who do mostly boondocking, it is better to redirect the small original solar panels that are connected to the house batteries, over to the chassis batteries. Those original solar panel(s) will be more than enough to maintain the chassis batteries.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
chuckster
Posts: 286
Joined: Thu Aug 27, 2020 4:53 pm

Re: Engine battery dead even when plugged in

Post by chuckster »

Any good ways to find where a small battery-suck is originating from? If I take an ammeter should I be able to detect a small drain? Any other gizmos to help? Ways to isolate? Tips for isolating the chassis batteries from the house batteries?

Where does the rooftop solar panel come into? Directly to the house battery terminals or elsewhere?

Thanks,
Chuck & Mitzi
'01 Safari Zanzibar 3646 (side entry)
Cat 3126B / Allison MD3060
Magnum M-Series "Blue Max" chassis
2016 Jeep Grand Cherokee Overland toad
05wingrider
Posts: 104
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Re: Engine battery dead even when plugged in

Post by 05wingrider »

Chuck,
A couple of things come to mind when looking for small current draws - start with the known simple ones - are all your basement and utility lights off? Are your vent fans all off? Turn off the switch for your steps in case they are trying to cycle for whatever reason. Make a list and go through and turn every thing off - and double check your list after you've written it down and see if it follows logic.

I know there's a way to use a meter and jumper across a fuse to see what kind of load it's being subjected to, but at the moment draw a total blank on what to look for- hopefully someone with far more electrical background can chime in? Also, your house and chassis batteries should already be isolated (thus the isolator and reason behind it) - the only time they should be connected is when the alternator is providing power, or when the boost switch is engaged. One more thing to look for - check and see if any of your relays or solenoids feel warm after the rig has sat for a little while - a warm one would indicate current passing through it and could give you further direction in your search. (Also check your alternator the same way - see if it's warm from current after it's been off for a while) Small draws are a pain in the rear (we fought one for years with the wife's car only to discover after getting rid of it that the culprit was her instrument panel)

Regarding the solar, on my 96 there is a small box/block in the front end that my solar goes into, then from there it goes back to my batteries. It's got fuses for both sets of batteries, so a simple way to eliminate it is to pull the fuses and take it out of the circuit.
Duane
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Engine battery dead even when plugged in

Post by stuplich@ymail.com »

Chuck
My solar controller looks like this:
Image
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Engine battery dead even when plugged in

Post by TDJohn »

Chuck,

To add to what Duane mentioned, be aware that the Allison VIM and the CAT ECM are mild parasitic drains, and you might have even more of them from an improperly wired relay or a slew of other possible issues. As Duane described, you can set your meter to measure amps and test at the fuses to see how much, if any, each circuit draws. If you have a large drain, check your heated mirrors switch, sometimes it gets left on or accidentally turned on.

You two battery banks should be isolated. If they are not, your chassis batteries should not be discharging while plugged in, but while not while boondocking, both of your battery banks would be discharging equally, which could potentially leave you stranded. By you describing that your chassis battery bank is going flat and the house bank is not, it would seem like your two banks are correctly isolated.

As I mentioned earlier, you could redirect you solar panel to trickle charge your chassis battery bank instead of the house bank. If you are interested in doing that, PM me and I will guide you through the process.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
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