View Full Version : Which battery load tester to buy?
drbrand
07-26-2009, 10:50 AM
Which tester should I buy to mainly test my deep cycle batteries? I looking at a variable 0-500 amp carbon pile load tester and a 100amp resistor type tester. The 2 testers can be seen at the links below.
http://www.amazon.com/500-Carbon-Pile-Load-Tester/dp/B001RAZPQG/ref=sr_1_7?ie=UTF8&s=automotive&qid=1248626436&sr=1-7
http://www.amazon.com/Actron-CP7612-Battery-Load-Tester/dp/B0009XQUJI/ref=sr_1_1?ie=UTF8&s=automotive&qid=1248626748&sr=1-1
mendota
07-27-2009, 08:35 AM
Neither is capable of measuring the capacity of deep cycle batteries. Both are meant to assess the starting current available, not the capacity.
You will burn them up if you tried to run them continuously.
drbrand
07-27-2009, 07:23 PM
Everywhere I read, they talk about load testing deep cycle batteries. I know a load test should be around 10 seconds, not continuously. Are you saying you should not load test a deep cycle?
Neither is capable of measuring the capacity of deep cycle batteries. Both are meant to assess the starting current available, not the capacity.
You will burn them up if you tried to run them continuously.
mendota
07-28-2009, 12:34 PM
Load testing a deep cycle battery is OK, but it doesn't really tell you what you want to know.
Which I assume is "how long will they run my troll motor?" rather than "will it start my engine?"
(Unless you just want to verify the battery is not complete junk - load testing will reveal that OK)
The only proven way to actually assess capacity is to discharge the battery at a given current and count the amp-hours til it reaches 10.5V. You can then compare the amp-hour result you get to the rated amp-hours, and also estimate run time if you know the amp draw of your electric.
I know of no low-cost equipment to do this. Worse, I believe MK stopped publishing maximum amp draw, so you would have to measure that yourself as well.
It's much easier to just make a point of running the TM long & hard at some point early in the season to assess the condition of the batteries, and to do reasonable maintenance and storage practices with them the rest of the year.
The resistive load tester (Actron)will do the job. They are most useful in testing a battery under load which will expose weak cells and the overall condition of the battery. I find them very useful and when combined with a good bulb type hydrometer give you a great overall assessment of a battery. The price is good too, if you have a Fleet Farm in your area they have a similar unit for the same money.
perchjerker
07-30-2009, 03:35 PM
I would go with the carbon pile as you can adjust the load.
Good point perchjerker, for the extra $20 it is a good/great deal.
perchjerker
07-31-2009, 11:52 AM
heck yea, you can use that tester for all kinds of batteries.
I have the other one, (have had it since about 1982 when I started my career as a mechanic) carbon piles back then were $300 or so.
The one I have is fine, but you have to interpet the results and it takes some knowledge to use correctly