You can purchase a decent battery tester, ("Schumacher BT-100 100 amp Battery Load Tester" : "Test load, battery condition, starter motor draw and complete charging system diagnosis") on Amazon for $35.
A battery monitor is a different piece of equipment than a cheap carbon pile load tester. A carbon pile load tester really tells you little to nothing about a deep cycling house bank. Heck a carbon pile load tester tells you little to nothing about most starting batteries other than confirming they are dead, which the ignition switch on your car can also do..
Only you can decide if it's worth spending another $225 (and you have to rearrange the wiring to make it work) for the MarineBeam tester.
A good battery monitor can easily pay for itself. Today I installed $2085.00 worth of batteries on a 40' sailboat. The $320.00 Smart Gauge battery monitor was a no brainier for the owner of this vessel after plunking down nearly $2100.00 just on batteries alone. He had an older Ample Power monitor that no longer worked and was removed. After the 25+ year old Ample Power meter dies he had gone back to using battery voltage as his way of monitoring SOC. As a result of doing this incorrectly, and no longer knowing how his charging system was working, he destroyed his last bank in just 3 years...
A
battery monitor is not a
battery tester. A battery monitors job is to tell you the SOC of the battery so you can maximize cycle life and attain full healthy charges. Some monitors can also tell you how many amp hours you've used or replaced and can even keep tabs on your charge system performance.
The two main types of battery "testers" are;
Impedance Testers are quite good at giving you a good look at your batteries cranking ability if you started with a baseline. They are horrible at predicting Ah capacity.
Carbon Pile testers simply apply a load 50A, 100A, 500A etc. and you watch the voltage sag and adjust for battery temp. They really are pretty useless for deep cycling house banks.
There are two main types of battery monitors:
- Ampere Hour / Coulomb Counters
Amp Hour / Coulomb Counters give a lot of information, amps, voltage, Ah's, SOC, time to go, remaining capacity etc. but require copious amounts of programming and owner level set up to work properly. They also lose sync with the battery over time and need continual re-calibration.
SOC Monitors simply track the state of charge of the battery and learn the battery to remain accurate as the battery ages. No programming is required and they get more accurate the longer they remain connected. These are the most simple battery monitors to use.
As for this battery monitor it seems like a step in a good direction but a 100A max shunt is not going to be very useful on a boat with a windlass, thruster or one that needs to start a diesel motor. Most other battery monitors utilize a 500A shunt. My other caution would be that I have seen no test data on Jeff's new battery monitors. I know they are supposedly "similar" to the Smart Gauge in concept but an actual major battery manufacturer tested the Smart Gauge and it passed with flying colors. We can't yet say the same for the Jeff's units.
I buy a lot from Jeff, LED's, wind generators etc. but have yet to try one of his battery monitors. When I do try one it will be the
BMPro as that one has some very good feature / benefits..
