Nathan J.

I need to get a battery tender for my car, as I am usually going a few weeks between taking it out for a spin. Any suggestions on brands and models that work well for you would be appreciated?

Thanks

Nathan

thomasmryan

I use a Schumacher 8/2 charger overnight once a month. it cycles between 8 and 2 amps every 120 seconds.

Ohio Performance

rggale

Big fan of the Sears DieHard battery maintainers. The basic one is like $20 and works just fine, but they also have an upgraded one with a digital display that tells you the battery voltage and % charged. It's a 6/12V unit so if you have toys of both varieties, you're in good shape.

chudson

This question may be akin to asking what tire is best, but I'm very happy with Deltran Battery Tender Plus. I have had one fail, but it was old and I'm not unhappy considering that I own well over a dozen and the majority of them stay plugged in 24/7. I could have sent in under the 10 year warranty, but it's a prorated deal and for the cost of a replacement it wasn't worth the hassle.

rggale

This.

They're all "good", but they are an electrical device. They fail, sometimes catastrophically (hopefully not!). I bet most of these are actually made in the same factory and just private labeled.

chudson

I once used these also and the old ones were practically indestructible, but when left on 24/7, the constant 120 second cycle tends to evaporate the acid from the battery. The "float" type of charger eliminates me having to constantly top up batteries and I don't have to remember which charger to connect or disconnect next or how long it's been there.

Possibly. There are some visual differences in the brands but all mine area made in China. Go figure...

Jfrahm

The $6 (with coupon) Harbor Freight one works fine for me, I did melt one once when I connected it to a totally dead battery by mistake but they may have fused it since then, that was many years ago.

Antigravity

My business is lithium batteries and contrary to what some have said there is a quality difference in the products you can buy. That does not mean that certain products will not work, but there is an absolute difference in the charging algorithm also called the charging curve, and some of the cheaper brands tend to not understand to stop cycling the battery at the end of the charge which reduces the lifespan of the battery. So if you want a top-quality charger stick with Optimate or CTEK. I really don't suggest any electrical product from Harbor Freight, it is really that cheap. Those Chargers way over cycle the battery and don't have the proper logic system to monitor the battery.

thomasmryan

Jfrahm

The HF trickle chargers (maintainers) do not appear to stress batteries, they do not really cycle the battery that I have seen. They do not AFAIK do an equalization charge but instead just keep a very low current charge that gets batteries into that surface charge zone. My shop battery was made in the year two-thousand and is the OEM battery from one of my Audis and it's been on the shelf when not getting used for something else since 2007, maintained with HF trickle chargers, and it's in great shape.

I have a couple smart chargers and some clever solar stuff for stuff out in the sheds and I suppose the smarter systems are better for the battery however I can say that as long as you don't hook one to a dead battery the HF maintainers have been 100% and no battery I actually maintained with one has failed. The battery I bought in 2007 to replace the 2000 is still in service as a backup I carry in my car for long trips. The HF maintainer does not boil the batteries. They do not do the equalization charge but that's OK IMO for a car that gets used, that equalization is for a battery that never sees an alternator hit it with a lot of charge voltage and current after startup.

Out back where I have no electricity I set up solar systems using $20 3W aluminum framed outdoor solar panels (straight from China, $20) and solar charge controllers similar to what HF includes with their 100 watt system, $6 again from China. These clever systems do a smart charge cycle and then maintain batteries. They also have a handy USB port I can use to keep a flashlight or work light charged up. Anyway these setups work very well as smart battery maintainers if you've got some sun and want the smart battery charge curve. Very nice for the lawn tractor and motorcycle hibernating through the winter, and inexpensive. You can get the SAE connectors off ebay also, inline fuses, etc. HF sells a cheap solar connection kit that is worth buying however I like fuses and those need to be added if you do too. No big deal, get a bag of inline fuses off Ebay when you buy the other stuff. The controllers I use have a display and you can see the voltage on them, and sometimes catch them in the act of doing the equalization. Kinda cool.

I can provide more detail if you like.
-Joel.

Paul Waterloo

I use the CTEK ones....and now have the latest and greatest, they have never let me down.

KevinGross

I use one from Porsche. Probably not the least expensive option, but it works and if it blows up my car, they have deep pockets.

Nathan J.

I ended up buying the CTEK MXS 5.0. Thanks to everyone for sharing opinions on this topic.

Nathan