I have some FleaBay special meters. I get a hit rate of about 75% good and 25% trash, but they are cheap enough that I don't mind. Do keep in mind some of them will NOT work with a shunt on the positive side without an isolated power supply and some won't work with the shunt on positive or negative if the meter power is supplied from the same system. I got power supply isolators for about $6 for this reason. Biggest PITA was mounting the meters. Joe Coquina
From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Dreuge via CnC-List Sent: Thursday, August 30, 2018 9:12 AM To: cnc-list@cnc-list.com Cc: Dreuge Subject: [EXTERNAL] Re: Stus-List Solar and batteries I was surprised at how well these $15-$20 meters work. I first installed one with a shunt about 2 yrs ago as a test to measure the power output for my house bank. I installed a second meter for measuring the charging input using the same shunt. Using the same shunt wired in reverse make installing the second meter trivial. There are no real cost savings regarding 2, 1, or 0 shunts as a meter with the shunt only cost about $2 more. Two nice features for using a shunt: safely handles larger current loads, and if a meter ever fails, normal battery operation continues. These meters display energy properly as Watt*hrs rather than the convenient (but improper) Amp*hrs, so you have divide by the voltage to get the Ah. I include the link to the meter I purchased below because the Amazon description shows several a nice installation schematics including separate solar, inverter, and input/output bank. I basically have meters #2 & #3 wired as shown on the solar wiring instructions (image 4) except that my engine ground (i.e. starter) is connected directly to the battery negative and not after the shunt. https://www.amazon.com/gp/product/B013PKYILS/ref=ox_sc_act_title_1?smid=A1T3LOAKNUUM9N&psc=1 - Paul E. 1981 C&C Landfall 38 S/V Johanna Rose Fort Walton Beach, FL http://svjohannarose.blogspot.com/ On Aug 29, 2018, at 10:25 PM, cnc-list-requ...@cnc-list.com<mailto:cnc-list-requ...@cnc-list.com> wrote: Date: Wed, 29 Aug 2018 22:24:47 -0400 From: Josh Muckley <muckl...@gmail.com<mailto:muckl...@gmail.com>> To: cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com> Subject: Re: Stus-List Solar and batteries Message-ID: <CA+zaCRCCBZTTh5_b-iOpMt=iiT0y0=pahusri-b+ns--snf...@mail.gmail.com<mailto:CA+zaCRCCBZTTh5_b-iOpMt=iiT0y0=pahusri-b+ns--snf...@mail.gmail.com>> Content-Type: text/plain; charset="utf-8" All lead acid batteries exhibit what I believe is called a surface charge immediately after charge. When doing any battery condition testing it is important to "burn off" the surface charge OR allow the batteries to rest for about 24 hours. At max charge rate (bulk charge stage) you will see voltage clime until it reaches as high as 14.6 or 14.7, particularly when on the engine or shore power charger (maybe not on a 50w solar panel.) Once the bulk is complete (80% charged) the voltage will hold at 14.7ish through the absorption stage and the max current will taper off until about 2amps. Once 2 amps is reached the charger changes to float stage which is usually ~13.3v. Assuming your charging system is large enough to fully make up for the usage, 13.3v is where you should normally find your batteries while on charge. After sundown 13.3v will decay to 12.7v. I have one of these on my solar charge system. It makes seeing and understanding what is going on much easier. This particular model is nice since no external shunt is required. You could even get two and then monitor the loads and the charges. https://www.amazon.com/dp/B017FSED9I/ref=cm_sw_r_cp_apa_Yp1HBbFG41PCM Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD
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