Same chargers?

I don't see different advice there. Please explain.

remove my-wife to reply :-)

| Hobby Lobby | AST109 Astro Flight 109 Lithium Charger for up to 9 Cells | Connects to a 12 Volt automobile battery and charges up to 9 Lithium | Polymer cells. | | Tower Hobbies | COMMENTS: IMPORTANT! Never use an automobile battery charger as a | power source, it could damage your charger. | | The above advice was given by two different suppliers. You can check | out their web sites. | | Could anyone explain the differing advice for using the same specified | charger?

Like the other poster, I don't see any differing advice.

One says you can charge it off a car battery. The other says not to charge it off a car battery *charger*.

A car battery charger often gives too much voltage for this charger, and without a car battery to `even it out', it can cause damage.

IIRC many automotive chargers put out something like 14.2 volts, which probably will fry the hobby charger. However, most automotive 12volt batteries that are not near the end of their economic life show around 13 volts when freshly charged. I would not use a hobby charger on a battery while I was charging it. Red probably has better info, but I try to be somewhat conservative with my choices.

one says can use automobile BATTERY, the other says CHARGER...;-)

I suspect it has more to do with AC filtering and inductance loading than supply voltage. Constant current chargers vary the charge voltage to maintain constant charging current. As the battery peaks, or at low charge rates, the charging voltage is lower. The higher the supply voltage, the more power it has to shunt and dissipate. It seems unlikely the small difference in voltage between a car battery charger and a car battery is enough to make or break whatever it is they're worried about. But then, I could be just passing gas. Heed the manufacturer's warnings. Read the specs and instructions to find out what was really meant.

Most automotive battery chargers provide a pulsed output. Some electronics, like computers and the like, don't like this type of voltage. Dr.1 Driver "There's a Hun in the sun!"

I would not use a hobby charger on a battery while I was charging it. Doug, I'm confused with this statement. Please explain. Do you mean you'd not use a "charger for a car battery " to charge a Li Poly battery? Not meaning to be a wise guy.

Now that I've re-read the advises carefully I do notice not to charge it off a car battery "CHARGER". I had read it as not to charge it off a car battery, missing the "charger" part. Sorry for being such a dupe.

So it's all right to use a car battery as a power source for the Astro 109 charger when or if I get one. I couldn't find one anywhere. Now if anybody would tell me where one may be purchased now, I would appreciate it.

Thanks, Wan

He means he doesn't see CONTRADICTING advice there. "uses an automotive BATTERY" vs. "never use an automotive CHARGER."

Reread it carefully. The advice is not differing, and does not conflict.

You can use a car BATTERY to power the charger.

You CAN'T use a car battery CHARGER to power the charger.

| > IIRC many automotive chargers put out something like 14.2 volts, which | > probably will fry the hobby charger. However, most automotive 12volt | > batteries that are not near the end of their economic life show around 13 | > volts when freshly charged. I would not use a hobby charger on a battery | > while I was charging it. Red probably has better info, but I try to be | > somewhat conservative with my choices. | | I would not use a hobby charger on a battery while I was | charging it. Doug, I'm confused with this statement. Please | explain. Do you mean you'd not use a "charger for a car battery " to | charge a Li Poly battery? Not meaning to be a wise guy.

It's not my statement. No wonder you're confused :)

Car battery chargers can work via a number of different methods. Some might be fine to use to power your charger, others might not. I wouldn't risk it.

It is ok to power your R/C charger from your car battery. It's usually ok to even use your car battery while your car battery is being charged or even if your car is running (and therefore charging the battery) though I seem to recall one charger somewhere (old, long gone, probably for that reason) that wouldn't work like that.

| So it's all right to use a car battery as a power source for the | Astro 109 charger when or if I get one. I couldn't find one anywhere. | Now if anybody would tell me where one may be purchased now, I would | appreciate it.

Personally, I'd suggest a Great Planes Triton charger instead if this is to be your first charger. Similar price, similar specs (but only 5 amps instead of 8), but it can also do NiCd, NiMH and Pb batteries. If you want the Triton, get it from Be sure to use an appropriate coupon code!

Don't get me wrong. Astroflight puts out good stuff, but the Triton really does kick ass for the price.

I ran my 1089 of a car charger with a car battery attached for some time. It works OK.

Best bet is Cosel 13.8V CB style supply

Why are you asking these eejits here?

has all the answers to your questions, and more.

I ran my 1089 of a car charger with a car battery attached for some time. It works OK.

this was not the orig>

Hey Six_O'Clock_High You hit the nail right on the head. The Auto charger will fry the hobby charger. Also the warning isn't that clear, some boneheads use a auto charger as a transformer to convert house current to the 12 vdc but the charger dc voltage is too high for the hobby charger.

Doug, Yes I was confused. As many posters have pointed out, I should have read more carefully. I bought my first Li Poly battery late last fall and have much to learn about Li Polies and their chargers.

The reason I want an Astroflight 109 is that I was told since it could input 8 amps for charging and I need 5 amps in order to charge faster than the ~2 hours (3S3P Li Polies) with the Triton (Max 2.5 amps, best I could get by the menus dial) that I have now.

I know the Triton took ~2 hours for a 3S3P, but is the information given me correct for the Astroflight 109?

Thanks, Wan

This first charger uses a 12V power source and will probably run off any decent 12VDC supply.

Home battery chargers do not produce a well regulated 12VDC supply. It may measure around 12 volts but it's far from pure DC. Consider it dirty DC.

Get the charger you desire but ensure the power supply (assuming 12VDC) is clean DC. Best source for that is a charged automotive battery or a modified computer power supply (computers require clean supplies).

It's less to do with voltage and more to do with how steady/clean the current is. Battery chargers are notorious for ripply/noisy outputs that

*approximate* true DC.

| Doug, Yes I was confused. As many posters have pointed out, I should | have read more carefully. I bought my first Li Poly battery late last | fall and have much to learn about Li Polies and their chargers.

Well, with regard to how they are powered, their chargers are not very different from NiCd/NiMH chargers ...

| The reason I want an Astroflight 109 is that I was told since it could | input 8 amps for charging and I need 5 amps in order to charge faster | than the ~2 hours (3S3P Li Polies) with the Triton (Max 2.5 amps, best | I could get by the menus dial) that I have now.

Didn't realize (never noticed, my biggest pack is 2200 mA) the Triton wouldn't do 5 amps on LiPoly. Wonder why ... must just be a software thing, trying to be `safer'. Certainly, the hardware is capable of it, because it does it with NiCd.

Since you already have a Triton, I guess it makes sense to get a specialized charger if that's what you need.

| I know the Triton took ~2 hours for a 3S3P, but is the information | given me correct for the Astroflight 109?

Don't know. You could call them and ask. (310) 821-6242. I have an Astroflight 110D, and it charges at 5 amps, even when charging a single cell glow starter battery, where my Triton throttles itself back to 1.9 amps or so (because it's putting out a lot of heat when you do that.) (Granted, the 110D does get pretty warm when doing this, which is understandable as it must be making about 50 watts of heat.)

Nonetheless I tried my Astro on a 90% screwed truck battery with a permanent charger attached to it. It worked as long as the packs didn't demand more current then the charger could deliver. Ther was just enough batteryness left in the truck battery to hold voltage between rectifier peaks I reckon :-) On its own the battery self discharged in a couple of hours off load, or in a couple of minutes with the charger.

Not the way to go permanently - I bought an ex CB PSU on Ebay - but its certainly a way to go in an emergency.

But without the battery nothing got damaged, it just didn't work at all

- rectified DC with no smoothing. I didn't have a smoothing capacitor to try...

Both my chargers - AStro 109 and a RipMax Pro Peak - were pants on just the charger. Neither got damaged - it was really cheap nasty DIY motor store charger.

Not recommending it, merely reporting some actual facts.

Doug, By "specialized" does this mean the Astroflight 109 charger would only charge Li Polies? I could live with that. Thanks for the phone number; (310) 821-6242.

I will call them and ask.

Wan