Battery Isolator, 100A, Black

this is a new method to maintain 2 batteries in a boat or RV, but keeping them isolated. It works well, requiring very little in the way of installation. (couple screws, couple wires, etc). If you are old school and know about the larger diode charging blocks (typically 2" x2" x 5" with large cooling fins) this is will do a similar function, but in a different way. This has a circuit to monitor the voltage, and when the main battery is charged enough, it will open up the charging to the aux battery (think boat starting and trolling motor). so as the first one charges up, the second will then begin charging. I contacted to the company to get their insight if would work correctly with an "A/B/Both" battery switch and they assured me that it would work (always turning on the battery to A, unless you have an issue, then you can use B or Both without worrying about the battery doctor having problems. the product does pull about 30mA when the boat is not running, and the way I have wired it, this happens even if my A/B switch is off. 30 mA will take a long time to drain a 100Amp Hour battery, but it is something to know for long term storage. I also added a trickle charger at the same time and this will actually allow the trickle charger to charge the main battery first, and then open up to charge my aux battery second. never wanting to be caught without a battery on the lake, this is an important component for my boat.

Update 2023: when my FLA bank died I replaced it with 150Ah of LiFePO4. I assumed I'd need a DC-DC. But I fired it up with the VSR in place and it works fine. Over the last ~20 runs, the average state of charge before start was 72%, bank voltage 13.20v. Charge acceptance after start was 0.183C (27.39A). See note below about using a switch to deactivate the VSR when desired. ------ I've had the isolator installed for [three years] and it has worked great, no problems. I would like to bring up a few points: * folks often say that this voltage-sensing relay connects the Aux battery when the starter battery is "fully charged"; that's not really what happens. Per the manual and my observation it makes the connection when the starter battery is >= 13.4v. Lead-acid chemistry batteries take hours to get "fully charged" (100% state of charge). In practice this means you'll start the vehicle and a few seconds later the relay will 'click' and you are connected. I don't know but I suspect this stepping-up in load is easier on the alternator. * if you are charging the aux battery[s] from another source while the batteries are connected (engine running, or recently turned off) any 13.4v+ charging voltage will be seen on the starter side and the relay will not disconnect. This may or may not be what you want. See below. * you can put a switch on the slim ground wire to deactivate the isolator. This might be useful if you want to do something like equalize the house batteries without feeding that voltage back to the vehicle. [I installed a High Voltage Disconnect (a few bucks here on Amazon) to disconnect the Doctor when solar raises the house side above 14.1v.] [I read a report about one of the connectors getting overheated - I suspect that person had a loose connection that overheated and melted the plastic. Remember to check your connections when you maintain the battery bank!]

as described I attached the unit to sheet metal with velcro, then black wire to ground and finally first power from fused auto to main terminal and then power from aux terminal to second battery positive terminal. all in all, 5-10 minutes including making custom cables. When ground wire first attached, nothing happened, then when attaching power from car, I got a flashing red light, now with second battery terminal hooked up, I got solid red. start engine and after 5-10 second delay you see a bright blue light, just as described. You can make your own relay set up, however both batteries will be in parallel, to start car, with this unit only starter battery is used. Now if starter battery dead just push a button which activates relay, and both batteries now in parallel to start your car. there is a model 20092 which is rated at 125-150 amps instead of 75-100 amps, which had I known about I would have spent the extra $20 or so on. Needless to say it worked perfect and extremely easy to install. With this unit you can throw away your booster cables as they will no longer be needed.

Easy install on my Kawasaki mule 600. I use it to have a separate battery to run sound system, neon lights, ect. I ran these accessories all day and night, starting the mule with no problems to charge second battery. I previously purchased an old school isolater, but couldn't figure out what wire was the charging wire coming out of the little grey box. This battery doctor solves/cut out that problem.

Using for auxiliary battery in the overlander. Keeps the battery charging. Still working 6 months in. Detects voltage from your alternator and connects 2 batteries together.

I like the product with some instillation issues. I have two of these units in my boat. One for auxiliary, one for trolling motor battery's. Both battery's are charged from the engines alternator. This setup had worked for several years till this spring, one failed do to water penetration. Although the installation is simple the instructions need to include critical assembly of wiring of battery cables. Some of this information was told to me from Tim from there tech support team witch I found better then most support you get now days. If you notice the plastic around the base of the post crack or you can see the o rings that are supposed to seal the post, you can assume the unit is no longer water resistant. I reinstalled my units in a industrial waterproof box (x stream overkill). A Tupperware box would probably work. 1. The flat washers (included) needs to be put on post terminals first. Under the battery cables. 2. The size of the terminal hole on your battery cables must be as close fit as possible to the post. If it is to large (as in my case) the flat washer will bend causing the plastic case to fracture around the post, allowing moisture to penetrate the otherwise well made enclosure. 3. Do not over tighten post nuts. As you tighten the nuts observe the lock washer (included), once it is fully compressed cation must be taken to not go much further.

Seems like a great product . I installed this and first thing on start up it had a flashing red light. look though the instruction and this code indicates its wired wrong. Well i triple check all my wiring and could not find any problems . So i let that lay aside and started the rig and got the voltage up to where it should of cut in and start charging, but that was a no go to. So i called their tech support and they were great,, however this Produit will not work with a lithium ion battery they said. otherwise really like how it installed.

No problems with this isolator, it's easy to install. Hard to review something which does exactly what is says it will do and does it without fuss or bother. Good product, good price.

Hasta el momento a funcionado bien, es de buena calidad.

Compact and waterproof design. I especially like the over ride/boost function. Any body want some old booster cables?

شكرا

خاص بعزل البطاريه جيدفي العمل

Works as described and was super easy to install. If the red light is flashing you just have to put a ground from the auxillary battery.