Auxiliary Battery

[Maine]

I am trying to gain a better understanding of the auxiliary battery system in my van and its capabilities. Please understand I am a bit challenged in this area. Here is the set up: The battery is an Interstate SLA 1161 Max charge 13.2 A. I purchased it new this year This seems to run most applications: interior lights, radio, faucet etc. There is a 1200 W Coleman inverter also. One of the biggest uses of the auxiliary system is to run the portable fridge/freezer that I use to replace the original refrigerator which has been removed. It is a Norcold 30 that I bought used, it has both AC and DC capabilities. I run it on DC plugged into a cigarette lighter socket mounted in back of the driver’s seat just below the inverter. The label on the fridge reads Voltage 12/24V CD Current DC 12V 4.5 A freezing capacity DC 24V 2.5 A refrigerator amount. I set the temperature at 42 degrees F.

On a recent 10-day trip I ran the Norcold while driving most of the time and when camped but turned it off at bedtime and turned it back on in the morning. What I noticed was the battery charge light indicator located on the cabinet never got in the green even after driving for several hours with the fridge shut off. I tried this a few times to see if I could get the light in the green. Most of the time it was yellow and occasionally red. I should mention the weather during the trip was very hot during the day often in the 90’s.

When I arrived home I pulled the battery an put it on the charger and it would only reach 11.8.

So my questions are:

What can I expect out of the auxiliary system? A friend who has a truck camper says his system can run for about three days.
When fully charged should the battery read moiré than 11.8?
Would a solar charging system help?
When driving should the charging from the engine outpace the needs of the fridge?
How accurate is the charge light on the cabinet?
Can I damage the battery if I run it down too low?

Thanks
Maine

[crazyvwvanman]

It sounds like the aux battery may already be shot. It isn't a large capacity battery to begin with at 44 amphours. It sounds like you have some charging problem with it. The 3 leds on the Westy panel are usually reasonable indicators of what is going on. But the green should be on when the engine is running if the dash warning light has turned off.

Without more info about your aux charging setup it will be hard to figure much more out.


Mark

[Maine]

Ok what do you need and where should I look?

[jimf909]

A fully charged battery will read about 12.7 volts.

A fridge is a fairly heavy load for a 44ah battery. Many folks running fridges have 100 - 200 ah of battery (I have 150).

Solar is very helpful (essential?) in keeping a battery charged while running a fridge while not running the engine. I run 150 watts of solar to keep the batteries charged while running a fridge and Propex. I’d like to go to 200 watts for more solar capture when conditions are not ideal.
_________________
- Jim

[noahk]

If you can't charge past 11.8, the battery is definitely toast. Fully charged it should read around 12.7. The fridge probably killed your battery. It sounds like you have the gowesty aux system, which isn't really intended for that much load. A 44ah battery gives you 22ah usable before its being damaged; at 4.5 amps for the fridge, you'll kill the battery in 5 hours, not including whatever other loads you may be using (especially if you're using the inverter). GoWesty also repurposes the stock relay and wiring, which is convenient, but doesn't pass a lot of current, so it takes a long time for the battery to recharge.

Solar will definitely help; anything really that will keep the battery charged. Ultimately though if you want to run a dc fridge you should probably look into a beefier battery and a better combiner such as a blue sea or yandina.

[Maine]

I believe the 4.5 amps is for freezing which I do not set that low the fridge draws 2.5 amps.
Can I get a more powerful battery that fits in that space?

[davevickery]

[Ahwahnee]

[crazyvwvanman]

The led should be on green when the engine is running no matter which battery is otherwise connected to them.

There has been modification, but we don't know exactly what.

If I cared enough to put in a toggle switch I would certainly care enough to put in a cheap voltmeter too, and switch that with the toggle rather than rely on only 3 leds across the wide charge state.

There are newer dual USB charger ports with integral voltmeter that would work great for this.


Mark

[E1]

As others said, a charged battery will hold 12.7 volts. Take it to any parts store and have them load test it, one of our batteries showed 12.7 once and I thought it fine... but under load testing that 1100aH battery had NINE instead of 1100. Yes, 9.

I finally bought a fabulous compact load tester at NAPA, after asking twenty parts stores for a compact one I finally stumbled into one on sale for $60, about $100 off normal price.

I also think a 1200-watt inverter may be dragging the battery down. It takes power, too, ours is an 1100 but we only need that for a blender and we have two 100aH batteries and solar. If I knew the bare minimum for the blender I'd replace it, for most common things I think 400 watts would be plenty -- though a bit of conjecture there that the more electrically-inclined can better answer.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[Gnarlodious]

[Ahwahnee]

I use a deep-cycle (trolling) battery (24DC-6) from Wal*Mart with 75 amp hours. About 70 bucks but lasts for many years though I don't have as heavy a demand on it as that fridge.

[Maine]

Could you give me a name of the battery I need?

[Maine]

I think it is the SLA 0190

[davevickery]

[E1]

[Maine]

This is the set up of my auxiliary battery. As noahk said it looks like the GoWesty aux system to me although to be truthful I'm not real sure what I am looking at.

[davevickery]

[Gnarlodious]

[E1]