Deltran Battery Tenders

[jos51700]

What I'm using (except it's a 12V)

Note that these are phased out, now they use some proprietary shape 'thing'.

I have had one of these Deltran Battery Tenders for almost twenty years, and just received a couple more from eBlagh. I was topping off a couple cars in the driveway today, and I noticed that the batteries were only hitting about 12.5V and the red light on the Tender never went green. Back in the day these used to leave a battery absolutely charged, but not cooked......juuuuuuuust right. I figured my memory was faulty and my batteries not far behind.
I grabbed my third tender and put it on a spare in the garage, and it was green within an hour....13.2 Volts. This battery has never seen a charger, has sat on the floor in the unheated garage for almost two years, and is only used with jumper cables to start my riding mower. This thing should've been on life support.

I've got this third tender on one of the other vehicles I charged earlier today with one of the suspect units, but I'm curious if any of you have used these and had similar issues. A friend of mine used one on his Buell motorcycle religiously that he bought in '06, and that battery just went south last year; that's a 16 year run. Thoughts? Is there a bad component in these tenders that I could diagnose/replace? They're build just like an old wall wart for your electronics. I've heard the new ones (like almost everything else) suck.

 

[Hellrats]

I have one of those and yes... it sucks. It will show the battery is charged but I will not start the car.

 

[jos51700]

I have one of those and yes... it sucks. It will show the battery is charged but I will not start the car.

That can be true of most battery chargers that don't have a lot of electronic hoopla, depending on the state of the battery.

I went out the truck last night and it was at 12.55V, BUT the lights were noticeably brighter when I opened the door and the diesel pickup started right up even though it's been 3 months since I touched it (other than putting the battery tender on for several hours yesterday. Given how warm the tender was, I'm going to venture that using a tender designed for Motorcycle and lawnmower batteries is probably is bit small when used on truck batteries (per the nifty instruction sheet I downloaded).

I also ordered one of these desulfators that was recently discussed in Mopar Action magazine. It was such a casual mention (in a tech article that was pretty low-key), that I almost missed it. I will post results when it comes in. Sadly: Only available from Chyna........

I'm still curious to see how it operates with only two wires.

 

[Princess Valiant]

Black and decker makes one that just works. I have had mine since 2015 and it's the best and most reliable battery tender / charger I've ever had. They still make them and I bought an additional one last summer and it's as consistent and reliable as the first one I bought in 2015.

Kept the lawn mower battery ready to go, all winter long and does it all

black and decker battery tender - Google Search

 

[Hellrats]

Thank you Princess Valiant I will for sure look into that one.

 

[Jeff Seighman]

I have used the Optima 400 maintainer for years it desulfates the battery too.