FULLY AUTOMATIC BATTERY GUARD FLOAT CHARGER with precise voltage and current regulation. These units ARE NOT Trickle Chargers. Doesn't drain your battery if the 110VAC EDISON source should fail or gets turned off. Has LED ON indicator as reminder. It has Reverse Polarity, Over-temp, and also has short-circuit protection. The BATTERY GUARD float charger is precisely regulated at a stable 13.5-13.8VDC maximum float voltage and WILL NOT overcharge or damage AGM or GEL CELL batteries. However, flooded lead acid batteries still need to be checked for proper water level, as long as the service caps can be removed to do so! The BATTERY GUARD will constantly monitor the battery self-discharge current needs and automatically regulates the float current from a required design spec as low as 2ma to a maximum of 525-650ma at initial FLOAT CHARGE STARTUP depending on the battery (to be float charged) state of discharge. It will charge all types of 12VDC batts including FLOODED LEAD ACID, AGM, GEL CELL, and others for either home, car, motorcycle, RV, or marine applications. Just plug it in and forget it's there! Footnote here: I also have recently modified one BATTERY GUARD to keep my 14.4vdc Black & Decker cordless drill battery pack properly maintained while it's not being used. The standard battery charger that comes with the cordless drill tends to overcharge it if left on too long. It works GREAT!! Continuing: Flooded lead acid batts should be properly topped off with distilled water prior to hooking up to the BATTERY GUARD. If intending to leave car/auto/marine type FLOODED LEAD ACID battery types on the BATTERY GUARD, or a FULL-ON HIGH RATE AUTOMATIC HOME/AUTO TYPE CHARGER, for years at a time, I would suggest adding a cell hydrogen-to-water converter to each cell to recover water loss. Usually you only have to add these in 'battery bank systems', or multiple battery groups where multiple batteries are being charged from solar photovoltaic or other recharging sources, and where they are being used purely for inverter backup power. I would also recommend first fully charging any/the intended battery, to be stored or FLOAT MAINT CHARGED, with a home/auto FULLY AUTOMATIC TYPE CHARGER similar to say a SCHUMACHER model# SE-520MA, or their newer SC-1200A FULLY AUTOMATIC SPEED CHARGE computerized switching type model. The WALMART model # is WM-1200A and cost is roughly $42 + tax. These are my personal choices, which I use to charge all my AGM type 12-volt batts that I use in my under-h2o diving equipment and AGM type batts I use for all my computer UPS units as well. They work flawless and to perfect battery specs I might add. I also use both as well on all my other car/motorcycle type flooded lead acid batts because they are a FULLY AUTOMATIC selectable type charger for under $50. WALMART, SEARS, and others sell them as well. You can email me if you need more specs or answers to any related ??'s regarding batteries or chargers, as I have an extensive background in ELECTRONICS REPAIR, as well as battery technology and design work using all types of batteries, as well as chargers for same. THIS FLOAT CHARGER IS ONLY INTENDED TO CHARGE ONE 12-VOLT BATTERY OFF OF ONE CHARGER. PERIOD! WILL NOT CHARGE ANY 6VDC BATTERIES!! It is solely designed however to provide just enough output to keep your home, boat, car, motorcycle, solar, and RV 12vdc batteries fresh during extended periods of non-use. Again, charging one battery at a time per BATTERY GUARD that is! It CANNOT and SHOULD NOT be used to try and maintain or recharge multiple, or parallel, 12-volt battery arrays. It is designed for and meant to maintain ONE battery at a time and only ONE battery! BATTERY GUARD float charger has a precisely regulated 13.5-13.8 volts DC maximum output voltage, and has an initial maximum startup output current of 525-650ma, that drops to a perfectly regulated 2-3ma maintenance float current, which replaces the internal self-discharge current of any FLOODED LEAD ACID, AGM, GEL CELL, or other similar type battery rated at 12VDC and 5-185Ah. I've done extensive testing/monitoring using these chargers on AGM type batts and the results were very, very impressive. GREAT performance for a charger costing only ~ $25.90 shipped, and that I would compare with others out there costing $35 or more in auto and marine stores. I've sold countless numbers of these float chargers to date and have NOT had a single one fail yet! So I guess they speak for themselves! I myself personally run 2 BATTERY GUARDS 24/7 on my 2 DACOR underwater dive scooter YUASA 24ah 12vdc batteries that are going on almost 9 years old now, and they still carry a great charge that gets me 1 hour or more underwater scooter time!! The scooter motor current draw is approx 20 amps FULL ON under tow load too! I keep telling myself it's time to replace them with NEW batts, but with the proper care it's not impossible to get 10+ years use from a good quality AGM type battery. You just can't beat this BATTERY GUARD price and quality as compared to some other supposed AUTOMATIC FLOAT CHARGERS costing twice as much!! BATTERY GUARD price of $25.90 is FIRM and shipping cost including the new MAY 2007 USPS postal increase for CA (NOT including delivery confirmation & INSURANCE) is included and is via USPS REGULAR GROUND PARCEL POST, unless otherwise agreed upon by seller, and is included in the price to anywhere in the USA. Leave your exact ZIP CODE for exact shipping cost quote based on quantity ordered and their total weight. Payment is by USPS MONEY ORDER or cash if local sale. Prepaid C.O.D. shipping will be considered on a one-4-one basis, with the buyer paying for any extra charges. If more then one unit is purchased together, then the shipping cost may be less. Email me your interests or concerns. Copyright 2000 by ST ENTERPRISES. All rights reserved. All photos and text are sole property of ST ENTERPRISES inclusive and may not be used without their permission. This ad has had 155,004 displays and 6,679 readers