Harness the power of the sun!
This Battery Tender product by Deltran is a 5-watt solar panel with built-in smart charging controller. This panel provides 100% portable battery charging and maintenance. Perfect when you lack traditional power access. Battery Tender solar panels are the only panels available with a built-in charge controller to prevent overcharging!
- Amazingly simple DIY installation
- 13.25" X 16" X 0.875"
- 3 lbs
- Built-in 3-step microcontroller for precise charging
- 12 V Nominal Voltage 270 mAmps
- Temperature Compensation Sensor
- Reverse polarity protected
- Sparkproof, waterproof: Excellent option for outdoor installations
- 5 Year Factory Direct Warranty (covers manufacturer defects only, not breakage)
I installed it on my garden fencer before I left on vacation for a month and it is working fine when I got back. It kept my battery charged.
Newer chargers have polarity guards ( will not charged unless connected to correct posts on battery ).
When connected to a battery, the charger "reads" the current from battery. If connected backwards it will not charge. Connect correctly, it will charge. With a completely dead battery ( no current flowing ), is impossible for any charger with polarity guard to detect ( read ) the polarity and, it is not going to charge. If battery is completely dead and you are using charger with detector, using another charged battery ( it can be a 9 volt or another car battery ), temporarily, connect good battery ( polarity correct, same as using jumper cables ), Connect charger, turn charger on, it will detect the polarity from the good battery and will now start charging. Leave temp connected to dead battery for maybe 15 seconds, then Disconnect the temp battery. Charger should now be charging dead battery. If not, chances are that battery is dead dead dead, take to local auto parts store, ask if they can charge it. Most will as, if it won't hope to sell you one. BUT >>> hard to beat Battery Mart Prices . Any way ... These Tenders have Polarity Guards ... Completely dead batteries have no current, thus charger does not work. This is a really low wattage charger, meant to slowly trickle charge and maintain charge on battery, not to quick charge a battery from dead. Is an excellent product when used as intended.
We have 2 at the boss's farm that look like they were in WWII. One has a bunch of cracks on the glass, but keeps on working.
There are several reviews on here that are incorrect! I'm a retired EE.
If you try to measure voltage out without a 'certain' level of battery charge, you will NOT see any output.
I don't know 'exactly' what that lower level is, but today, I tried this test on both solar panels:
Three 12V sealed batteries.
Both panels put out voltage on the 12.5V and 10V batteries, but zero output on the 0V (discharged) one.
This is exactly what the other reviewers were seeing. So, DO NOT connect this panel to a dead battery, it has to have SOME life in it! It will NOT overcharge! I watched it 'question' the 2 good batteries and stop/start accordingly.....
this battery tender is used for my riding mower, it's keeping battery fully charged and have had no problems except for having to extend lead wires.
The instruction manual should be more detailed as to the nature of Charging batteries - it is not obvious to all and everyone. That would avoid disappointments with the performance of the product
I too tried to verify the voltage output on the unit and got nothing from a voltmeter. I was concerned after leaving this charger on a battery for several months to find the battery was dead when I went to start the four wheeler. I tried to verify the voltage while hooked up to the battery and then after disconnected. I got zero voltage while un-hooked and it read ~6 Volts while hooked up. But her
Tested this with a digital meter -- no voltage & no amperage readings in bright sun. Batterymart referred me to Battery Tender for repair / replacement, but I haven't gotten a response from them in a week.