|
| Author |
Message |
rayyy
Member
|
# Posted: 19 Jan 2015 05:14pm
Reply
My question to you battery experts,Can I test a marine deep cycle battery on one of those load test gagets used on car batteries?Some of my batteries are getting pretty old and I need to test them for my battery bank?
|
|
MtnDon
Member
|
# Posted: 19 Jan 2015 06:23pm - Edited by: MtnDon
Reply
In a word, no. The commonplace auto battery testers just check to see if the battery can produce sufficient power for a short duration cranking. They can not determine the actual capacity of the battery, which is what you probably want to know and compare battery to battery. See below though....
You can get something of an idea by applying a load to each battery individually, for the same length of time. Then clock the time for the volts to recover to an arbitrary value. Write down. Perform the same test for each battery. That can help to determine if any battery is significantly less healthy than the others. For a load a carbon pile battery tester could be used. Or be creative. 600 to 1000 watts would likely be good.
|
|
MtnDon
Member
|
# Posted: 19 Jan 2015 06:29pm - Edited by: MtnDon
Reply
This one works
http://www.cadex.com/en/subscriptions
and last time I found a price it cost as much as all 12 of our gc-2 batteries.
|
|
groingo
Member
|
# Posted: 20 Jan 2015 05:14pm - Edited by: groingo
Reply
I was going to have mine tested earlier and the place that did it was a golf car service center and they ran it over a 24 hour period.
|
|
bobrok
Member
|
# Posted: 12 Jun 2018 05:24pm
Reply
If I can revive this thread, I need to check only one deep cycle battery, that is, the one I use to power my Surflo demand pump for water to the cabin. Does turning the water tap on and off occassionally (dishes, shower) qualify as a short duration?
Does turning on the water qualify as a load test?
|
|
darz5150
Member
|
# Posted: 12 Jun 2018 09:54pm
Reply
Quoting: bobrok Does turning on the water qualify as a load test?
Our system also flushes the toilet. Soooo I would assume that would be a load test. And also the size of the load directly affects the duration!
But I haven't harmed the batteries. Going 7 years so far on 2 batteries.☺
|
|
ICC
Member
|
# Posted: 12 Jun 2018 10:39pm
Reply
Quoting: bobrok Does turning the water tap on and off occassionally (dishes, shower) qualify as a short duration?
I would think, Yes.
Quoting: bobrok Does turning on the water qualify as a load test?
Not in the normal sense of load testing a battery.
A battery load test is a lot like the stress test a person may be given on a treadmill where the person is forced to exert themselves. A light load like a small pump won't prove much just like a slow walk on the treadmill won't prove much about the lungs or heart. A person walking does not put much stress on a heart and lung system, unless the person is already in bad shape. Ditto a battery.
A load equivalent to about one half the rated amp-hours of the battery would need to be applied for about 15 seconds. The voltage drop is measured. The test is similar to what would be done on a vehicle battery. If the off grid system only was one or two batteries you could probably get a good idea using a vehicle battery tester. If the system uses many batteries in a bank, then each battery tested separately should give a decent idea of battery condition.
If you have one of those watt-hour meters you could rig up a test bed using a known load, like a pump or lights, or whatever, and measuring how much energy (watt-hours) is pulled out of the battery over an extended period. If the battery had a rating of 200 amp hours and you had a 10 amp load then you should be able to run the load for about 200/10=20 hours before the volts drop to 10.5. Assuming a 12 volt nominal battery starting at full charge.
A hydrometer will provide lots of health info if the battery is a wet cell with removable caps.
|
|
bobrok
Member
|
# Posted: 13 Jun 2018 12:18pm
Reply
Thank you for this information. I did test with a hydrometer and the reading, although equal across all cells, was about 1225 which indicates fair/recharge. The battery had been on a charger/maintainer and was showing fully charged before testing.
It's five years old and spends most of it's time on the charger, only being used for 1-2 week durations when we haul it to camp.
My guess is that it's close to the end of it's life cycle.
However, if all we do is run the water pump with it I would think I could stretch it out until it just won't take a charge any longer.
Thoughts?
|
|
|
ICC
Member
|
# Posted: 13 Jun 2018 12:58pm
Reply
Most people run their car battery until it won't start the car one day. For some purposes, the battery is changed on a timetable or certain test criteria, like the cells not coming up to a high enough level. (Fire engines, and mission-critical equipment) Do the same, when it won't hold a charge long enough to get what you consider a reasonable operational time for the water pump. Unless having a long shower becomes the mission-critical reason to buy a new battery.
|
|
bobrok
Member
|
# Posted: 13 Jun 2018 02:23pm
Reply
Can't argue with that reasoning!
TY
|
|
NorthRick
Member
|
# Posted: 13 Jun 2018 03:40pm
Reply
Quoting: bobrok My guess is that it's close to the end of it's life cycle. However, if all we do is run the water pump with it I would think I could stretch it out until it just won't take a charge any longer.Thoughts?
|
|
NorthRick
Member
|
# Posted: 13 Jun 2018 03:49pm
Reply
As long it is still doing what you need it to do, it's a good battery. The only real risk of using it until it is completely dead is that it might happen in the middle of needing that water. If you have an alternate way of getting water or can easily run and buy a new battery then I would run it out.
|
|
|
