andrewsfm

iTrader: (3)

So everyone says, get a second battery.
What do you guys think about using one of these as a second battery?

UB12350 (U1) - Universal 12V 35AH SLA Battery

They're used in power packs to jump start dead cars, so they have to have some power to them.

Small enough to strategically place right in the back by the amp.
Downsides? Anyone try this?

John__Taylor

iTrader: (3)

Poked around some, but did not see any CCA specs on it? I have a couple of those power pack things, biggest is 500a, I can tell you that mine take a long, long time to die if you are running a moderate 12v tool off them.

I dont know if batts can be designed this way, but my concern is it may be a type of batt designed to "dump its charge" quickly in one or two shots (for example to boost a car), with pretty minimal reserve.

Cheers

andrewsfm

iTrader: (3)

I found the CCA rating for another smaller battery...

http://www.apexbattery.com/ultra-tec...batteries.html

The chemistry is close to what you'd find in a car battery, except it uses a gel instead of liquid acid. I don't think they're designed specifically to dump a load of power though.

I'm just wondering if they would help in a car audio environment, as a second battery/capacitor-type device.

JohnVroom

http://www.apexbattery.com/ultra-tec...batteries.html
1- it is a toy... (5 pounds) it has no real value for car audio
2- do not buy it for automotive use it can not take the temperature extrems, but it would be an OK jump start batt (110 CCA is kind of small)
3- t does not say it is a gel (which would indicte a deep cycle battery) or AGM sust sealed
4- the first one is ok for a jump start battery

andrewsfm

iTrader: (3)

I was only referring to the last link to the smaller battery for it's listing of a CCA value. The spade terminals on top of that smaller battery would be useless in a car audio setup.

I don't think weight has much to do with the equation. Lithium ion batteries are pretty light, and can pack more punch than Nickel Metal Hydride batteries, in a cell phone for example. Capacitors don't weigh a whole lot either.

As for the temperature extremes, they are used in car booster packs, which are stored inside of a vehicle. The freezing cold is the most likely time you'll need a boost too.

The link page also says below the specs "The state-of-the-art lead-acid battery is the valve-regulated type (sometimes called "sealed" or maintenance-free), which fixes the acid electrolyte in a gel or in an absorptive fiberglass mat." It is not a liquid battery.

Let's discuss this some more...

JohnVroom

um... this isn't about lithium batteries or NiMH or NiCAD... this is about lead acid batteries, and the constituents that make power are sulfuric acid H2SO4 and lead (Pb) the more material the more power (the geometry of the design matters too i.e. spiral cell etc.) so more lead and acid=more power as well as more weight. Capacitors are not even worthy of discussion as a power source (since they don't produce power) they merely hold charge. Lithium isnt affordable and would not like the automotive environment under the hood and is currently too damn dangerous (but it would be superior to the lead acid from a weight and size point of view).

a lead acid batteries performance is determined by the amount of chemical energy available to do work, as a battery gets cold (and Canada does cold) its ability to perform chemical reactions decreases thus it's CCA goes down (some manuf. rate for cold and hot CCA). so the booster battery will have the same issue as the main battery BUT there isn't a dome light draining the booster battery

I didn't say it was liquid nor AGM nor gel since they didn't say... all they said was sealed and that is a blank check (and it still could be liquid BTW since we are reading ad-copy)

and let me finish with "it is a toy, it has no real value and it is not appropriate for automotive use" (sound familiar)

I actually read and understand your posts... buy a real second battery that can perform as desired (preferably one identical to the primary battery in the vehicle) and a wet cell would only cost maybe $60

andrewsfm

iTrader: (3)

After more research, I think I am looking for an AGM battery specifically.
Like this one...
Sealed-AGM-Gel-Golf-Cart-Battery-12-Volt-35-Amp-Hour

Rigidly mounted plates to withstand extensive shock and vibration. (Comes in handy when mounted near the subs.)

Since all the electrolyte (acid) is contained in the glass mats, they cannot spill, even if broken. (Acid leaking in the trunk would be BAD.)

Since there is no liquid to freeze and expand, they are practically immune from freezing damage. (Always a bonus.)

Even under severe overcharge conditions, hydrogen emission is below the 4% specified for aircraft and enclosed spaces. (Can't say the same for flooded batteries where you have to worry about sparks around them.)

They can occasionally be discharged much much deeper than conventional deep cycles without major damage. (Flooded batteries shouldn't be discharged more than 50%.)

Now with all of this in mind, I'm looking to basically use one of these smaller batteries to supplement, not replace my existing car battery.

godzilla1978

what about the charging resistance of these other batteries? Since their not really made to be in the car how would you charge them, and if you can what damage/problems will it cause to the alternator. The golf cart and booster pack batteries charge differently(voltage, amps, charge time) that could cause problems as well

andrewsfm

iTrader: (3)

Hmm... Well I did find this...

For flooded wet batteries, internal resistance can be as high as 26%, which is the charging current lost to gassing, or breaking up of water.

Gel acid batteries are better at only approximately 16% internal resistance and require only roughly 116% of rated capacity to be fully charged.

AGM technology has the lowest internal resistance of any battery manufactured with resistances as low as only 5%.

"Due to their very low internal resistance AGM batteries will fully charge at a lower voltage, and accept a much larger charge current, so when charging from a standard car/truck alternator these batteries will all but fully charge in about 3 hours." (Quote didn't specify what size battery they are referring to. It was taken from a wind power generating site.)

They also said on one webpage that BMW uses AGM batteries as the primary batteries in their high end cars in Europe.

I wonder how all of that translates into what you were referring to.

godzilla1978

it's pretty much what i was getting at. I think the stress that those other types of batteries will out way the benefits. It's more expensive to do a gel battery now but in the future it could save you lots n lots of money