Load testers?

[chris63]

Where (and which one)does a guy get a quality load tester for 7,9&12 amp gel cells from.I see those small led indicator lights that come with a lot of the depth finders,however I would prefer one that I can actually preform a load test on the batteries themselves.c63

[Hafnutz]

I use a digital VOM. Switch it to the voltmeter part and take a reading. I was told by Marcum customer service that their units will function normally down to about 11.9 volts. I usually charge it until it gets into the 12.9-13 volt range. You can buy a small VOM at any electronic or hardware type store. They start at about $10.

[PerchJerker]

I do the same thing, I use a digital multi-meter. It's not a load tester, it measures voltage with no load on the battery.

[fishwater]

Run a 12volt (60watt) automotive bulb in series with the DMM while testing voltage. That will give you a better indication of the charge quality.

[chris63]

Voltage is good and fine.I want to know what my reserve capacity is in my various batteries.(amp reserve not voltage.)You can read 12.9 v and be at .5 amp reserve.I want a load tester not a voltage meter.(DMM)digital multimeter.Thanks for any/all suggestions.c63

[fishwater]

The only way to know how much reserve capacity is to drain a battery by drawing a prescribed amount of current until dead. You can buy battery testers that place an internal load (some resistance, ie. a light bulb) on the cell while tested and are calibrated to represent the total potential of the battery from that short reading, but most are designed for batteries that output 200-1000amps. I'm not even sure if you can buy one of these pre-made load testers for smaller capacity gel cels? And if you did this is really just a slightly less crude approximation than slapping a DMM on it.

I'd suggest hooking up a light bulb, or some other resistance and then testing your voltage. Far better method of determining the charge on a battery than testing without any load. If you really want to know the load potential or quality of a 12volt gel cell more accurately than this for all loads, you would need to measure the internal resistance of each individual cell in the 12volt battery and cross reference this with your drain (capacity) test and make a nice graph.

[chris63]

Thanks fish you've given me food for thought.I did locate a load tester designed just for gel cells (2 to 200 amps).Thanks again for all replies!c63

[Whoaru99]

Does the cost of a load tester really outweigh buying a new $20 battery every few years?

[chris63]

I get used batteries for free and some of them are bad.So in answer to your question,yes it is well worth the investment to tell if your batteries are holding a full charge or not.I run as many as 6 gel cells depending on what/which/equipment or place (perm/Porty)I'm/were going to be fishing.C63