14 Kw Kohler generator starter battery

Bonei

I have a 14Kw Kohler generator that I use in an off-grid situation.I use it as back up power for my battery bank when the solar panels can,t  keep up to the demand or when I have a heavy demand like a welder. My problem is the starter battery keeps draining. When we leave the cabin the inverter is turned off and there is no draw ( that I can discern). Everything  has worked well until the last 2 months then I started having problems with the starter batteries ( I have two that are located in the workshop beside the Gen., I ran heavy welding cables to the gen) I have a quality stand alone battery charger that tops up the batteries while the inverter is turned on. It seems to me it is the gen itself that is draining the batteries. I am miles in the boonies so it is not so easy to get a tech there. Does anyone have an idea what may be the problem 

Marc Kurth

How old is the starting battery? It is common for starting batteries to dramatically increase their self discharge rate as they age.
I would use a clamp on ammeter to look for power drain on the genset. Or, pull a battery lead next time you leave and see if the batteries are still up to par when you return.

There are probably many decent low cost meters out there, but I have been using two of these here in my shop for 8 or 9 years. They are certainly accurate enough for trouble shooting.
http://www.sears.com/craftsman-digital-clamp-on-ammeter/p-03482369000P?sid=IDx01192011x000001&gclid=CJzNidXvmdECFQ6oaQodCC0OcA&gclsrc=aw.ds
 

Estragon

How cold is the workshop?
How old are the batteries?
Are the batteries identical?
Flooded or AGM?
How long did the batteries go from last charge?
Does the generator start and run okay when boost started?

Are you able to test for current in the wiring from batteries to generator? If the generator is meant for standby, there could be control circuits monitoring ac for startup, transfer switch, timer for gen exercise, etc, but sounds like a new problem. I'm not familiar with this generator. Is there an offgrid mode setting that could have defaulted to standby mode?

BB.

A typical solution is simply to set up a small solar panel and charge controller to keep the battery charged.

If the genset is the only charging source--A genset backing up a solar power system does not run often enough to keep the starting battery well charged.

Some gensets have a bit of draw to run the electronics.

And depending on the battery type you pick (flooded cell, generally need 24 hours of charging at least once per month; AGM need 24 hours of charging once every 6 months minimum)--You can play a little bit between a solar charger vs just letting the system sit for 6 months by picking the battery type.

-Bill

mike95490

Many generators have none or minuscule charging circuits. Both of mine have none, so I use a Genius G3500 floater to keep the shared battery charged.   Common generators have a 5 or 10 a charger, which is fine when it runs for 12 hours.

Once the generator battery is charged, the smart chargers consume little power

Bonei

It is cold here! 0 degree F at night, my batteries are 9 mos old and identical flooded deep cycle type. shop is unheated.
They get charged fully each time we are at cabin which is almost every weekend.It takes only a couple days for them to discharge when not being used. I pulled a lead last time there so after we get back from Maui which will be in three weeks, I will see what state the batteries are! Thanks for the help . Happy New Years!

Estragon

At 0F FLA batteries will have substantially reduced capacity. They also should self discharge very slowly, so something does sound wrong. Good that you lifted a lead when leaving as when discharged the batteries can freeze.

My island-a-day calendar happens to be on Maui today. Looks lovely. Apparently parts of the island get 17" of rain per year and others get 300"! Have fun.

mike95490

If you have a 12V battery system and solar, why not use the solar to keep the generator battery topped off, using a conventional automotive battery isolator - wired so the generator battery is considered the "house" battery.

Bonei

I have a 24 volt system but where i am located (B.C.) is not like AZ. I have many trees that block the sun especially around my shop so a secondary solar charging system would not be viable I have had to put the 4 panel solar array (1000 w) down by the lake, a good 250' from the shop. I have my Absolyte 2 volt AGM batteries (12) and inverter in my cellar under the cabin which never gets below freezing and never above 60*.  In winter I get about 3 hours of direct sun. In summer l get enough sun that the generator is basically not used from April until Oct. After reading some comments here, I have come to the conclusion the generator must at fault or some wiring related to it. so it looks like I will have to become a self taught expert on this generator and system. After Maui though !
Happy New Years! 

oil pan 4

On my 7kw I use a 100 amp breaker to disconnect the battery when not in use.
On my 17.5kw generator, I might need a slightly larger breaker.
This helps to keep the battery from draining.