Chassis batteries not charging with engine alternator

[det944]

Took the 2006 Dynasty for a spin last night prior to my upcoming trip from Savannah to St Mary's GA. I noticed the batteries, (house and chassis) were not being charged by the alternator. I started the Genny and everything charge normally. I need to still check the alternator output at the post but it looks like it may need to be rebuilt. If I'm unable to source a new alternator or get it rebuilt, is it ok to use the Genny to charge the chassis and house batteries for my 2 hour trip to St Mary's and back? I am plugged into 30 amps at home and will have 50 amps at my camp site. Thanks, Dan

[Ivan K]

I drove like that about 400 miles when our alternator quit on a return trip. Our generator only charges house batteries and then a maintainer steals some current from them for the chassis and that would not have been enough so I had to jumper both banks together with a piece of wire i had available. You would likely have a different factory system so just make sure both banks get charged by the generator, be it through the big boy or a jumper.

[Cubflyer]

3 minutes ago, Ivan K said:

I had to jumper both banks together with a piece of wire i had available. You would likely have a different factory system so just make sure both banks get charged by the generator, be it through the big boy or a jumper.

As Ivan said, you need to be sure that both house and chassis batteries are being charged by the genny....  I have a BlueSea in place of my Big boy contactor (that joins the two battery banks together).   That allows me to run them isolated or automatically charging the lowest battery or combined (to do just what you are needing at this time).   I never run combined when driving with both the alternator and genny charging... (two sources of charge fighting to charge one combined set of batteries... bad)

Ken  

[Michael J]

I think your question is, is it ok to run generator while traveling.

I do it all the time especially on hot days and run my AC’s

[Wheelsnkeels]

I just resolved this issue today the battery isolator had failed if you move the alternator (center terminal) to the chassis terminal and it charges that is your problem. You can run it that way until replacement.

the alternator is available from AJ Electric on Amazon they also provide free troubleshooting support very nice people.

https://www.aj-elec.com/

Edited November 21, 2022 by Wheelsnkeels

[det944]

Thanks for all the feedback. When I checked alladin with the engine running after about 1/2 hour, chassis battery voltage was around 12.1 volts. After starting the Genny, it rose to about 13.8. If I understand the system correctly, I think the BIRD would have prevented the Genny from charging the chassis batteries if alternator charging was available. Unfortunately I cannot run the engine to take alternator output readings until I replace the ruptured coolant line to the turbo, see other post. Hopefully I'll get that done tonight.

Thanks! Dan

[det944]

Ok, so I replaced the ruptured turbo coolant line so I could do some voltage checks with the engine running. With no charging input, battery voltage was 12.8 vdc at the battery and positive lead on the alternator. When I started the engine, voltage dropped to 12.4 volts and slowly decayed. I removed and replaced the alternator thus afternoon and everything is normal. Chassis batteries are charging initially at 14.2 but within 5 minutes, decays to about 13.6 -13.8 vdc. I believe the alternator corrected the charging issues as both the Genny and shore power charging are Normal. Thanks for everyone's insight and feedback.