103 of 112 people found the following review helpful
Great if you know it's not a bulk charger,
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This review is from: Deltran Battery Tender (021-0128) 1.25 Amp Battery Charger (Automotive)
I bought one, for my own use and spent much time reading Deltran's website, and the finally the info that came with the Deltran unit.
Over all, Works well, made well (vented metal case). I've been testing it on a 55ah AGM.
I have a lot of background in battery chargers. Based on my review of the unit I bought, I wanted to maybe offer some general practical help for those that can't find all the info they need for guidance before they but such a product.
The price at Amazon makes it worth it, but not list at the OEM's site. The OEM list price is pricey for the Battery Tender Plus, the Battery Tender Jr is about 1/2 (based on the OEM price), and can take care of much of the same duties.
While I've read all I could from their site, all their advertising pre-sale doesn't warn that it may not charge a large cell that has been properly discharged. Once I bought my Battery Tender Plus, I found liteature comes with the charger that warns you of this..
I figured as much and bought it as a compliment to my smart bulk chargers that aren't good maintainers. The reason.......
If the power is interrupted on any of my bulk chargers, they don't come back to the correct profile, just the profile for 2amp charge for a wet cell general. Not the AGM profile.
The Deltran being a dedicated maintainer doesn't suffer from this problem.
If the power was to be cycled, it would just go through it's profile again. And since it's such low current, no harm.
These Tenders are Great for when the bulk charger is taken care else where on the larger RV, boat, or secondary car battery. Your primary car battery is charged by the alternator, and when you store the car you need to take care of the self discharge issue and any parasitic loads that will discharge your car's battery while in storage... the Battery Tender Plus is great for that.
As well as the Battery Tender Jr, if you have very little or no parasitic loads.
(if your parasitic loads are too great, you may need to disconnect the battery from the vehicle for storage - if the parasitic drain/loads comes close to the tender's rating, it wont do it's job and your battery wont be a happy battery)
I've been testing the Battery Tender Plus on my optima AGM, and on maintenance float, the battery is only pulling a .01a at 13.2vdc. Just right. The profile was just about perfect, per optima's spec and other AGM's spec, and perfect for wet cells (normal car batteries).
If you have larger parasitic loads, the Battery Tender Plus (1.25a) will be a better choice. But if you pull your battery lead of have little or no parasitic loads, the Battery Tender Jr will work well and save you money over the Battery Tender Plus.
(Again, remember if your parasitic loads are too great, you may need to disconnect the battery from the vehicle for storage - if the parasitic drain/loads comes close to the tender's rating, it wont do it's job and your battery wont be a happy battery)
For a motorcycle battery, the Battery Tender Plus is probably the end all charger.
But for the larger batteries, neither Tender will serve as a bulk charger. To protect your battery investment, get a good smart bulk charger (not the cheapo dumb bulk chargers) with the right profiles, and use the Deltan Battery Tender Plus or Battery Tender Jr for storage.
After the testing I've done (monitored and recorded voltage, current, and temps to see what the profiles are of the chargers), for my storage use, I could have gotten away with the Battery Tender Jr @.75a, for my storage "tender" of a single 55ah optima agm battery.
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Initial post: Jan 31, 2012 6:49:36 PM PST
I just read through the Battery Tender info on their site and the Plus models are indicated for AGM batteries, according to them, because the absorption stage of charging is longer for that type of battery, and the Plus models have that charging algorithm, whereas the non-Plus models (like the Tender Jr) do not. Apparently using the wrong charging algorithm on an AGM can shorten its life by a factor of up to 4. Just repeating what I read there...
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