I would just turn on lights until I got to around 20 amps. You can get 100 watt 
12 volt bulbs at West < 
https://www.westmarine.com/buy/ancor--standard-screw-base-bulbs--P009_276_006_521?recordNum=3>.
 2 or 3 of those would do.
For a temporary setup, a standard cheap halogen car headlight is usually about 
55 watts on low and 60/65 on high. Two of those running high and low beam would 
work. You do not have to be exactly at 20 amps, 15 or 25 will do. What you do 
need to do is set a timer to go down and turn them off at the 50% point and you 
need to be able to measure the amps to get this right. This is NOT going to be 
exact, but it should roughly tell you if you are near the stock capacity.
Here is something to watch: I bought a new gel in January and it seemed to go 
dead very fast. I returned it and the shop tested it with good results. Back to 
the boat and it sucked again.
??????
The temp sensor circuit on my charger had died and it was getting summer charge 
settings. I got a new battery charger that could properly sense battery temps 
and the battery was fine once it was charged appropriately for cold weather.

Joe
Coquina



From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Ron Ricci 
via CnC-List
Sent: Tuesday, February 07, 2017 11:55
To: cnc-list@cnc-list.com
Cc: Ron Ricci <rvri...@gmail.com>
Subject: Re: Stus-List Battery test

Dave,

If you used a resistor, you’d need 0.6 ohms at least 240 watts.  Probably not 
practical.  You could put a load on your batteries by turning on most of your 
lights, cabin fans and other loads.

Ron

From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of David Knecht 
via CnC-List
Sent: Tuesday, February 7, 2017 11:32 AM
To: CnC CnC discussion list
Cc: David Knecht
Subject: Re: Stus-List Battery test

I have been following this discussion and would like to do this for my 
batteries.  Can you suggest what would be an easy/appropriate ~20A load 
generating device?  Dave

Aries
1990 C&C 34+
New London, CT

[cid:image001.png@01D28138.02844420]

On Feb 7, 2017, at 10:15 AM, Della Barba, Joe via CnC-List 
<cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> wrote:

Easy cheap way.
If you have accurate volt and amp meters,  a 20 amp (or near enough) load 
applied for enough time to drain the batteries 50%*. You should see 12.2 for 
wet cells and 12.3 or so for gel/agm.
Light loads like 1-5 amps and heavy loads like 50-100 amps both will be 
inaccurate because of Peukert’s law. This law deals with the fact that  a 100 
AH battery can supply 100 amps for 1 hour or 1 amp for 100 hours in theory, but 
in practice 1 amp will last longer than 100 hours and 100 amps won’t make the 
full hour. 20 amps is a good value for these tests.

* (AH capacity of batteries/load in amps) /2 = time in hours for 50% discharge

_______________________________________________

This list is supported by the generous donations of our members. If you wish to 
make a contribution to offset our costs, please go to:  
https://www.paypal.me/stumurray

All Contributions are greatly appreciated!

Reply via email to