Star Cool drains house battery while driving

ralph62 · 07-01-2009, 02:49 PM

Why does my Star Cool a/c draw down the house battery while I'm driving?
Also how long do the average starter batteries last?

yvrr · 07-01-2009, 07:41 PM

There are a couple of options with the Starcool A/C...we have the one which allows A/C only when driving. I assumed that it was driven by the engine battery and therefore should not have any impact on the house battery. The other option also provides A/C when hooked to shore power. Is that what you have? Either way, it doesn't seem that there should be a draw on the house battery. I wonder if your starter battery or alternator is a problem (and not providing enough power for the A/C) and that problem is draining the house battery through the separator....but I'm getting beyond my knowledge.

As far as the starter battery, if it never goes dead (headlights left on, etc.), it should last a long time. We replaced our starter battery last year or so (at around 6-7 years old) even though it tested out fine....just being cautious...

**daveb** · 07-02-2009, 01:44 PM

Ralph that seems to be common with the Starcool. Is your rig a diesel? I've talked with several owners that have had the same problem. But it all depends on what else you have on in the van such as headlights, stereo equipment...etc. The problem is the alternator just can't supply enough to run everything all at once and the engine itself takes a big chunk. I was finding that if my solar was shaded while driving I lost about an amp from the house battery system (not starting batteries). Ford check the alternator and claimed it was OK. I installed a 200 amp alternator and now I get no less than +5 amp to the house batteries with everything on including the Starcool. But you could have other problems going on also. If you have a diesel and one of the starting batteries is failing, it will cause a host of problems and the vehicle will still start. I had one fail within 2 years. After a long drive see if one or both of the batteries are unusually hot. A bad battery can rob some of the amps the alternator puts out.
Dave B

Skywagon · 07-02-2009, 06:23 PM

Also, when you're figuring alternator output, I believe that when an alternator gets hot, ie: in a diesel engine compartment, it's probably only putting out about half, or a little better, of what it's "rated" capacity is. We had this problem on a boat once. The alternator was running all the time full tilt and never filling up the battery bank. The batteries never filled up and let the alternator kick off. A 200 Amp alternator is probably a really good thing to have, esp. with Star-cool.
Bill

ralph62 · 07-05-2009, 09:19 AM

How much to put a 200amp alternator on the Ford350 Diesel? Also did you have to upgrade your isolator and any wiring?

**daveb** · 07-05-2009, 05:53 PM

You're probably talking around three to four hundred depending who does it. If I remember correctly the alternator was about 250 bucks but don't quote me. I didn't have to do anything else except switch the alternator. Ford does not make a 200A alternator so an aftermarket unit will have to be purchased. The one I bought is made by MCI but their web site is worthless for my use. Anyway the part number on the box is 88 1-2173-200. But just make sure that's your problem before jumping into this. I had a very small loss from my house battery and I never killed it. What would happen is after a long ride while running the Starcool at night, when I pulled into camp I noticed my battery was not fully charged. During day I had no problems. There is the possibility of you having more than one problem. Check your batteries, connections, and then do an amp check. Make sure all the connections at the separator are clean and tight. Someone on this site had a cable that was compromised so it's best to make sure. The way I looked at it was I could use all the extra charging capabilities anyhow.

Dave B

ralph62 · 07-06-2009, 08:16 PM

Will check. I saw a price of approx.$250 for the alternator too.
Thanks. We'll see what we can find.

ralph62 · 07-14-2009, 11:06 AM

Went to SMB Austin and they found a wire from the alternator to the separator that was bad. We think this was the problem. We'll keep you posted.

Scalf77 · 07-14-2009, 01:49 PM

I hope it works out and that was it. For clarification do you know what made it a "Bad" wire.

Greg

ralph62 · 09-03-2009, 06:53 PM

Quote:

Originally Posted by Scalf77

I hope it works out and that was it. For clarification do you know what made it a "Bad" wire.

Greg

I will have to find out. I'm still having problems with charging with Starcool fan on and Refrigerator.
Even with sunny days and driving 70mph it seems to lose charge.