battery maintainer

[incoming]

Hello gents,
It has been a while since I have been on the site. I've appreciated all the help and good advice I have gotten from you. My plans were to pull the engine in the MUTT in order to get the the access panel for the four wheel drive shifter rod and fork but haven't had time to yet. Hunting season keeps me in the woods. I do have a question that you can help me with at this point however. Is it possible to hook up a 12 volt battery maintainer without unhooking the batteries in the jeep, and still maintain a charge on both batteries? Any advice would be appreciated. Will keep the site posted on the engine pull when I get to it. Thanks as always!

[wolfeman738]

Try a Battery MINDer Model 244CEC1 24volt. Northertool or check on line for one. They have other 24 volt models. I use one on my M151A1 at the jumper connector in the front. The jumper connector comes if you have hot water heater. I used brass charger push in connectors (neg.- pos.+ that were made for another charger I had. This way you don't have to get in the battery box to hookup cables. Just remember to remove before driving off. The Battery MINDer charger works well with 2HN batteries on my jeep. Hope this helps.

[rickf]

What Wolfeman said is the best way to do it. You can charge them in the vehicle but you will either have to do one at a time with them fully hooked up or you will have to disconnect the cables to set them up to charge both at once on 12 volts. A lot of work if you ask me when there are 24 volt maintainers out there fairly cheap. Get a slave connector and hook into that if your mutt has a slave plug.

[Horst]

To your original question. Yes, absolutely you can use two 12V battery maintainers, one on each battery. I am using CTEK chargers, one per battery to keep the batteries up over long storage periods with both batteries in place and hooked up to the 151. In fact I have installed a short harness and a waterproof connector permanently on each battery and running it under the battery cover. I have to disagree with Rick here, no need to charge each battery on his own, no need to unhook anything.

Now if your 151 has a slave connector, I agree with everything else said, connecting a 24V charger is the way to go. (My 151 has no heater and as such no connector).

[Bart1015]

I also use a 24 volt Battery tender. I mounted it on the celling of my garage and extended the charging cable. I cut off the clamp ends and hard wired it into a slave plug for the cowl of the truck. I also have a hook on a beam next to the tender. When I unplug the truck, I reach up and hang the plug from the hook so its out of the way.

I did drive off once with it still plugged in. Fortunately, I had maintained the battery tenders' factory type plug between the tender and the slave plug and it simply unplugged itself.

Brett

[rickf]

Horst, He said "A" maintainer as in singular. Yes, you can use two chargers without unhooking anything but to answer the question as asked I went with no. I have done the same thing when my batteries went down and hook two chargers up, one to each battery and never disconnected any cables.

[incoming]

Once again, you guys have come through with some great options. I have a slave receptacle on my MUTT so it sounds like getting a 24 volt maintainer is the way to go. Sounds like I will need a 24 volt military issue jumper cable to hardwire the maintainers to and plug that into the receptacle. I'm wondering if the leads on the jumper cables are labeled or color coded so I will know which wires from the maintainer to hardwire into. Am I on the right track now?
Thanks again, you guys are great!

[Fil Bonica]

Slave cable connectors are expensive and some times hard to find.
Bought mine at Findley last year for just that purpose.
Another way would be to use a slave cable nato to two pin adaptor and solder wires to it
If you are VERY Careful you could use two proper sized bolts and insert them in to the connector.
The connector on the cowl is marked Plus and Minus so you shouldnt have a problem identifying.
Just some thoughts.

Fil Bonica

[incoming]

Phil,
Found a two pin slave cable on Ebay for a hundred bucks, in great shape. I'll probably buy that and hardwire it into with a 24 volt maintainer. Thanks for the info.

[kmam]

Another option: I pulled the guts out of my slave connector (a previous owner had cut the cables off about four inches from the connector) and fitted an Anderson power pole in there. Cheaper than $100 and makes it compatible with other electrical equipment I use.

Howard

[Fil Bonica]

A nato adaptor r connextor alone should be less than forty bucks.
Better than ruining a slave cable.

Failing that connect the maintainer directly to the 24 volt point in te battery box with an Anderesen power Pole connector.

Another solution.

Fil Bonica

[rickf]

OR, Use the connector that comes with the Battery Tender. Zero dollars. Hook to batteries through the hole for the radio connector in the tool box.

[pvtwinger]

I used to use a 24 volt Batter Tender to maintain both batteries. But, after a winter when I tried to start it I had low voltage. Although the charger was green indicating that it was in "maintain" mode one of the batteries was not taking a charge, and even though everything appeared OK, the one battery was basically dead.

To prevent this from happening again I got 2 brand new batteries and a 2-port 12 volt Battery Tender. It came with alligator clips and eye terminals. I attached the eye terminals to the batteries and ran the wires through a hole in the battery box. You can connect one set of cables to each battery as long as you connect the (-) negative cable to the (-) negative battery post, not a chassis ground. Doing so isolates each battery's ground.

Using the included cables with the quick-disconnects I can connect the charger without removing the battery box lid. Now I charge each battery separately with 12 volts but with the 2-port Battery Tender. It works great and I can see the status of each battery.

Here is the 2-port Battery Tender. The price is high here but it the manufacturer site. You can get them cheaper elsewhere on the Internet (such as Amazon).

http://products.batterytender.com/Charg ... phere.html

Here is a photo of my setup.

[rickf]

I know it is a battery tender but I do not see anything there about being a maintainer, I see charger. There is a difference. What that one is saying is a constant 1.25 amp charging current. If that is true then you will cook the batteries. You need something in the 1 amp range for topping off the charge but it then needs to drop to a milliamp float charge to maintain the battery.

And charging with a 24 volt charger has a downside and that is what you saw, you can have one battery fail and the charger will at that point overcharge the other battery. There is no substitute for actually physically checking the batteries occasionally during the off season.

[pvtwinger]

I know it is a battery tender but I do not see anything there about being a maintainer, I see charger. There is a difference. What that one is saying is a constant 1.25 amp charging current. If that is true then you will cook the batteries. You need something in the 1 amp range for topping off the charge but it then needs to drop to a milliamp float charge to maintain the battery.

This is directly from the website I referenced in my post:

"The 2 Bank Battery Tender® Charging Station is two encased 1.25 amp battery chargers designed to fully charge a battery and maintain it at proper storage voltage without the damaging effects caused by trickle chargers. This charger will operate anywhere in the world."

I've used these Battery Tenders for years and never had a cooked battery or any other issue with them. I have 6 of them and use them on lead-acid and AGM auto and motorcycle batteries, and all their lights are glowing a nice green in my garage now.