Battery Maintainer for 3 Amp Spree Battery??

SanJoseMichael · Post by **SanJoseMichael** » Wed May 20, 2009 1:02 pm

I recently picked up a Duracell 2-Amp Battery Maintainer (made by Xantrex), and the literature notes, "Note: Three-Stage Charging. Multistage charging ensures batteries receive optimum charging, but with minimal wear and tear, regulatingthe voltage and current delivered to the batteries in three automatic stages:

Bulk: Replaces 70-80% of the battery├óÔé¼Ôäós state of charge at the fastest possible rate.

Absorption: Replenishes the remaining 20-30% of charge, bringing the battery to a full charge at a slow, safe rate.

Float: Voltage is reduced and held constant in order to prevent damage and keep batteries at a full charge.

And, the spec sheet says "Internal battery size (recommended) 6 - 50 Ah"

My 1985 Honda Spree NQ50 has a 3-Amp battery... under the recommended 6 amp on the spec range. Question: Can connect this maintainer and just leave it plugged in?

I don't ride often but want the scooter to start when I do.

mousewheels · Post by **mousewheels** » Wed May 20, 2009 2:28 pm

There's not a lot of detail for the charging states at the mfg website

http://www.duracellpower.com/documents/ ... harger.pdf

I believe the 6A limit is being driven by the 2A output in the fast 'bulk' charge mode. For smaller batteries that is higher current than some battery manufactures recommend.

My guess is if you have a standard lead acid battery (wet cell) it's going to be ok, especially since you state mostly it would be idle. That would place the charger in the 'float' mode, where the 2A charging current would not be a factor.

SanJoseMichael · Post by **SanJoseMichael** » Wed May 20, 2009 2:40 pm

Yes, it's a standard lead-acid battery. Given the puny size of the battery at 3 amps can anyone recommend "plug-it-in-and-forget-about-it" charger?

And, any opinions on a 12 volt solar maintainer? Supposed to put out 125 mA (http://sunforceproducts.com/english/details.asp?id=65O?

mousewheels · Post by **mousewheels** » Wed May 20, 2009 2:58 pm

Battery Tender jr would do the job and gets good reviews.

http://batterytender.com/default.php?cP ... 7d51bf6530

On the dirt cheap side, I've been using a Harbor Freight Float charger for a couple years on a Spree sized battery. Its about $10, but often on sale for $5-$8.
http://www.harborfreight.com/cpi/ctaf/d ... mber=42292

Scooterspal · Post by **Scooterspal** » Wed May 20, 2009 4:02 pm

SanJoseMichael wrote: And, any opinions on a 12 volt solar maintainer? Supposed to put out 125 mA (http://sunforceproducts.com/english/details.asp?id=65O?

I used a solar maintainer for years and years on the dashboard of my 1990 VW Vanagon bus when it was parked where I worked. Kept my battery topped off nicely in the winter. Still have them both... but I broke down and bought a new battery a few years ago.

Any small 100ma 12volt DC wall wart will work to keep your Spree battery topped off. Just make sure you have the correct amount of distilled water in there and check it every so often.

SanJoseMichael · Post by **SanJoseMichael** » Wed May 20, 2009 5:39 pm

Thanks to all for great info. Can't go wrong with the low-output Harbor Freight unit at that price!

I may have a 12v 100ma wall wart in my box o' stuff, but that's a pretty low rating, can't think of what kind of device it might have powered. We'll have look anyway.

And, since I do have a 12V solar maintainer that I got for $20 or less that never did work with my son's Saturn... as I'd figured out that when the car is parked, keys removed, no voltage from/to the cigarette lighter. Since I do live in San Jose, sunny northern California, sun is something we gotta lotta. I'll nail it to the roof, get some connectors, ring terminals, etc, and see how it goes.

Thanks again.

mousewheels · Post by **mousewheels** » Wed May 20, 2009 6:02 pm

A bare wall wart would be better used on a a connect and remove cycle. They are typically unregulated. Solar charger is also likely to be unregulated.

Float chargers have
a) A regulated output set appropriate for long term battery connection.
b) Temperature compensation, to match the need for a higher voltage at low temperature, and to protect the battery from overcharge at high temperatures. The low cost Harbor Freight model does have temperature compensation, will update with a graph tonight.

Edit - added graph of HF Float Charger Vout vs Temperature showing temperature compensation.

Both features will help extend the life of your battery.

Edit - Added note --> 'This info is from a commercial battery vendor'
Unregulated Transformer-Based Chargers

These are the absolute cheapest chargers around. They consist of a wall mount transformer and a diode. The transformer is designed to deliver 13 to 14 volts over a reasonable current range. The biggest problem with this approach is that when the current tapers off, the voltage raises to 15, 16, 17, even 18 volts. At these high voltages electrolysis of the water in the battery starts in. These must not be left to trickle or float charge a battery, they must be disconnected when the battery is fully charged.

SanJoseMichael · Post by **SanJoseMichael** » Wed May 20, 2009 10:02 pm

mousewheels -

Thanks for well though out and well written feedback and info.

Okay, if we discount the solar panel + diode idea, and the brainless wall wart, and I stick to my Duracell/Xantrex (and assuming we are past the "Bulk" stage) then perhaps the 2A Duacell/Xantres is fit for purpose? I do note that I am now in "Float" where the green LED is constant and the red LED ("Charging") flashes perhaps once per two or three seconds. The presence of LEDs seems to indicate a certain amount of IQ in the unit.

I do acknowlege that the Battery Tender Jr at .75A is probably the best maintainer for a 3 to 4 amp battery, I also see that it costs about equal to two new batteries!

SJM

mousewheels · Post by **mousewheels** » Wed May 20, 2009 10:31 pm

SJM,
Yeah I think the Duracell charger you have is much better than a wall wart as well as unregulated solar (provided you have AC..) and in your usage will probably work just fine.

Back to first reply...

My guess is if you have a standard lead acid battery (wet cell) it's going to be ok, especially since you state mostly it would be idle. That would place the charger in the 'float' mode, where the 2A charging current would not be a factor.

BTW - Don't know what happened with the Battery Tender Jr price. I thought it was under $30 from online sources. Maybe shipping is jacking it up?