WirthCo Battery Doctor 20092 Dual Battery Isolator, 125/150 Amp, 12 Volt, Electronic Parallel Charging with Manual Override, IP62 Water Resistant, 4 x 4 x 2 Inch

Works perfectly! Safty first, when we started this solar build with a bank of 4 12v AGM batteries to power 2 separate 12vdc to 120vac inverters (1- 2500w and a 10,000w), I purchased a few of these isolation. That way I can charge the start up battery and keep it off of the circuit when I want, ensuring the vehicles ability to start won't be compromised should the solar bank be used up. I even put a bypass temporary contact switch in line on the starter battery to give the starter circuit a boost if needed. Overall, great product!

If you’re running a second battery, I’d highly recommend getting this. You want to hear it, here it goes. This is a smart battery isolator, charger, and jump starter all rolled into 1 palm-sized device. When installed correctly, you can run power into your secondary battery without affecting the main starting battery. The device stays on for less than a minute between shutting off your vehicle and running parallel with your main battery. So there will be a small parasitic draw for balancing both batteries during that minute. This compact device has 3 connection points, main battery, secondary battery, and pre-wired ground. I highly recommend using a fused 4 gauge or higher cable from the main battery with the fuse or breaker fuse closer to the main battery, and a fused same gauge or lower wire out to your accessories from your secondary battery. Following the instructions I realized it wasn’t charging my secondary battery and wondered why. I later found that my main battery was faulting and after charging it for 8 hours didn’t hold a charge past 64%. With that said, it will only charge your secondary battery IF your main battery is charged past 13.4V. Once I got my main battery sorted (new one), everything was working as it should be. FYI, if either your main or secondary battery loses connection, the isolator will shut off by default. I tried to run the isolator in override mode to swap out the main battery without losing power, but found out that it simply shuts itself off. It’s a good thing. I also found out that this thing has a built in voltage spike regulator, similar to a power conditioner. But I wouldn’t consider it to be a conditioner either. Before this, I had an 80A Stinger battery isolator/relay between the main and secondary battery. I also had a 150A fuse breaker between the secondary to my rear fuse box for my accessories that kept tripping only during vehicle startup without any accessories ON. Battery to battery was fine over 80A relay, but the surge of power introduced by the alternator kept tripping my 150A breaker. After installing this, I had my 250W light bar ON running out of the secondary battery without tripping the breaker during startup. So in short, it can detect power spikes and send the correct signals. I highly recommend this if you’re into the whole secondary battery and trying to stay within budget. What’s $53 compared to potentially burning your entire electrical system (undercharging or overcharging) or getting stuck in a remote place without jumper cables. Hopefully this helps you think about what this thing is actually doing and what you’re protecting. I have a truck with a V8 5.0L engine and a stock 150A alternator, and the 125A/150A works for me. V6 and smaller motors with smaller applications can easily use 75A/100A system.

I've been using this for over a year now. My primary battery is an Odyssey Extreme which is the starting battery, and I have a smaller Braille AGM that runs the winch, emergency lighting, and siren/PA. This reliably charges the secondary while preventing unwanted discharge from the primary. It only charges once the main is fully charged just like it should. The override also works well and is easy to use, so the secondary can charge the primary like a jumpstarter if needed.

I am a amateur radio operator (Ham radio) and I have 2 batteries and this device works great .This is my second one i buy first one .Someone else needed more than and they stolen it from my vehicle. It clicks back in forth plus has a button to where both batteries can be used to jump start you car .Not sure how it works but if you someone with more than one battery it works ..it will charge #2 when car is running and when it shuts off it automatically shuts down the #2 battery so you can have a back up ☆☆☆☆☆

No Luck so far making this device operate. I have a 1971 VW Bus and wanted a aux battery for accessories without draining the starter battery. Installation was easy and followed very easily. I have a 7 month old starter battery. Once I hooked in a ground wire from the aux battery to the frame the red blinking light turned solid red as stated in the instructions. I start the vehicle and the blue charging light never came on. Thought, well I will drive around and see what happens. I found out that my starter battery kept draining while the aux batter remained charged...but still no blue light.Basically it has killed my (fairly new) starter battery and I got it replaced - did find out on numerous occasions that the jumpstart feature works GREAT!!! New starter battery in, same thing exactly as written above. Back to square one. Called tech support, "Tim" was very helpful and said it may be that the circuit board is defective and to return it. I did and waiting on a replacement. I hope it works, but the new starter battery has probably suffered some damage from being discharged frequently. Tech support also mentioned that the unit will not work on a positive grounded vehicle and suggested that may be my issue. No, the VW Bus has a negative ground system....but people who may have a European car that has a positive ground system, this will not work. I will update once I get the replacement, but just don't think it is going to work but hoping for the best. The instructions said it goes into charging mode when the starter battery is above 13.4v....well, that is probably the problem as even the starter battery read 12.8 volts BRAND NEW. Not too sure how to get it up to 13.4? Really disappointed this did not work for me so far and caused a lot of troubles along the way. Looks like many people had a good experience. ****UPDATE**** Batteries, mostly the starter battery was low. Decided to put it on a charger while still in the vehicle. Next morning to my surprise the blue LED light was on! Turns out it is working properly, I was just not getting the proper voltage due to a pre-existing alternator condition. Got the alternator wiring corrected and this product works as described and like a champ!

Extremely easy install. Works as advertised. Very happy with this purchase, so far. UPDATE: I've adjusted the 5-star rating to a 3-star rating. Well, the honeymoon is over. LOL. The unit has been installed for a week and it's already acting fritzy. It was really great while it worked, but now long after I have shut the engine off, the blue light continues to burn. I tried pushing the reset button. It didn't work. I had to disconnect the entire unit to get the blue light to go off. When I reconnect it, the red light burns solid, as it should. I turn on the engine, the blue light clicks on. I shut the engine off...the blue light stays on. I've come back hours later to find it still burning. The only way to get it to turn off is to disconnect it. It's seems to be a defective unit. I'll probably be sending it back, unless there is some insight that WirthCo can share with me. The aux battery IS an agm battery, so that might have something to do with it. If this is normal behavior for the isolator when connected to an agm, my apologies. I will correct my rating back to 5-stars. UPDATE FOR THE UPDATE: The blue light will stay on when the AGM battery is completely full, which mine often is, since I wired it to a solar panel,too. When the AGM is slightly depleted, the blue light shuts off about a minute after I shut the ignition off. This is apparently very normal.

I want to start off with the fact that in todays time nothing last forever. That being said I have read reviews were others battery Doctor failed shortly after or months later. I have been using this Battery Dr for almost 10 years here in the south with heat and humidity being tough. I have only used the self jump start feature once as a test. I am running 2 red top optimas on my truck one for cranking and the other for my car stereo amp with intentions of running other aftermarket items that I Just haven't gotten around to. I dont have much else to add other than that so far it has not failed me in the few months under 10 years of operation.

Aux battery voltage is 12.5, main battery is 12.9 with engine off. With engine on the main battery is showing 13.6 across the terminals. Dealer advises that this is normal charging voltage for a Toyota Tundra. The blue light on the Battery Doctor starts flashing when I start the truck indicating over charging. The aux battery voltage stays at 12.5 until I press the override button when the blue light goes out and the voltage across the aux jumps to 13.1 After a few seconds (maybe 5) like this the blue light starts flashing again and the voltage across the aux battery drops back to 12.5. Aux battery is fused at 20 amps and the fuse does not blow. I am outside of the return period. The WirthCo site does not have any tech support email. I think this product does not work as advertised. Very disappointed, can't recommend this product. Update: I emailed [email protected] and asked for tech support. I received an email reply and the technician has been very helpful but the problem has not been solved. I have been asked to package up the unit and return it to Wirthco as a warranty return. We will see what happens.... Update (9/11/19) - I shipped the unit back to wirthco at my expense. They examined the unit, determined that it was not functioning properly and are shipping a replacement at their expense. Wirthco believes that the unit was working properly when shipped but failed due to the use of improper gauge wire between the isolator and the aux battery. While I have my doubts about the root cause I have no other substantiated suggestions as to why the unit failed. I purchased this unit in late 2018 and Wirthco is replacing it in Sept 2019 so they are certainly supporting their product. Although this has been a trial I have been very happy with the support I received from Wirthco. Upgrading my rating from 1 to 3 based on the extensive technical support provided. I will update again once I have installed the replacement unit. Update 7/17/20 - Tried to use the unit for the first time this year and the blue light is flashing again and there is no charge at the battery. This product worked for about 3 weeks last fall but does not work now. I tried different batteries with no luck. Blue light continues to flash. Installation was in a 2011 Tundra. Going back to hooking into the 12 volt supply to my 7 pin trailer connector. Sorry I purchased this. Would not recommend this product.

يتركب بين البطاريتين نفس عازل السنيدي ورفيق الدرب وبسعر افضل. يفصل بين البطاريتين اول ماينزل مستوى البطارية الأساسية وفيه ازرار لشحن البطارة الأساسية من الإضافية له خمسة أشهر راكب على السيارة والحمد لله بدون ملاحظات

Good product and useful

My previous battery isolator failed. When I looked at replacing it the same make/model I had was only $30 so was definitely cheap & nasty. I bought this WirthCo item based on other reviews. Installation instructions were dead easy. Item worked first go & hasn't missed a beat. Similar devices were much more expensive so this was good value for money.

I previously used a cole hersee on my last truck.it worked great but required external switches and led. This unit is smaller, cheaper and required no extra switch or light. Seems to work great and is electronic vs solenoid so time will tell Very pleased so far 2020 chev. suburban, install required 2 x 150 Amp breakers plus 30 Amp breaker hard wired to trailer feed. The second battery in the truck powers and recharges my trailer battery and allows effectively endless use as every time we drive the truck it recharges the battery and then we can reconnect to the trailer using extension cable the ability to boost the truck is a nice bonus which saved me on my last truck as the battery aged but this one is still young and the battery isn't dying yet update.. year later 8 camping trips 50,000 kilometers more on the truck and this unit is working great very very pleased

Just purchased a solar system for the caravan and this product was highly recommended to compliment and stop battery drainage. The product is as explained and is of good quality .