| [GMCnet] Hot start needs boost [message #305561] |
Thu, 18 August 2016 11:48 |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
Hi Paul,
No need to be afraid of a combiner. They simply combine two batteries when a charge current is present on either side and disconnect those two batteries when there is a small differential in battery voltage between them. So, no matter what the charging source (converter/charge or alternator) both batteries will stay fully charged. There are several brands to choose from. Yandina, Victron, and Blue Sea are three widely available brands and you will find these and others from our GMC vendors, from many sources on line or from any marine supply store. Costs vary from around $50 to over $100. They are generally very reliable but I have had two of the Yandina brand combiners fail in one or the other of our two coaches. I have never seen or heard of a failure with the more robust (and a bit more expensive) units from the upper end brands like Blue Sea (made in Bellingham, WA). Most have a light to tell you when they are combined, but the Victron I have has no such light.
In our 1978 Royale we have a single group 31 marine start/deep cycle chassis battery and four 230ah deep cycle wet cell six volt house batteries wired series/parallel. A Blue Sea combiner sits between these two banks. In our 1977 Clasco there is a single AGM start battery up front, a 200ah 4d AGM by the generator that handles all the inverter loads and a 100ah group 31 marine start/deep cycle AGM under the bed that handles all the house 12vdc loads (mainly LED lights) and which is used to start the generator. That splitting of the house batteries closely matches how we live in the coach with about two thirds of our dry camping electrical needs coming from the inverter to power small draw 120vac appliances, the microwave, TV, satellite antenna and all the recharging of pads, pods, phones, laptops, cameras, etc., and one third of our dry camping electrical needs coming from running the LED lights, furnace, propane refer, etc. A Victron combiner sits between the chassis AGM start battery and the group 31 AGM house battery and a Yandina combiner (I carry a spare) sits between the 4D and the group 31 house battery banks. In both coaches, all battery banks stay fully charged whether we are plugged into shore power, running the generator or going down the road with the engine driven alternator doing the work.
As I reported earlier we encountered an electrical gremlin while on the 8,600 mile Alaska jaunt earlier this summer that somehow caused our chassis start battery to go dead over night while dry camping. I could not find the cause at the time. Once we got home I found hidden under a panel under the center section of the rear lounge in the Royale three ground circuits had been connected to a single wire going to the aluminum house framework by Coachman Industries. That connection had come loose meaning those three circuits had to find an alternate path to ground. I have no idea how that could result in the loss of the chassis start battery over night while dry camping, but it somehow did.
I tell this story as a way of recommending you go far beyond “just” the obvious connections others have outlined while trying to trouble shoot why your chassis batteries seem to have such a short service life. While a pain to do, I suggest you investigate all your house ground leads to make sure they are all sound and resistance free — and I recommend you change out that diode isolator for a quality combiner to make sure both battery banks receive a full charge from all sources. Hope this helps.
Jerry
Jerry & Sharon Work
Kerby, OR
glwork@mac.com
http://jerrywork.com
78 Royale with most everything done to modernize a GMC mechanically
77/94 Clasco bone stock (except for FiTech EFI) and looks like it just left the Clasco facility
Both drive equally as well.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
