Battery types for model subs

[corsaire]

I'd have to look up what the "% charge" equivalent is, but the number I've learned to use is 3.8V / cell for storage. As for "how long" before you call it storage, like everything it's a sliding scale. Think of LiPo's like an elastic band; when you leave them stretched all the time they will start to lose their "spring". The better you treat your batteries the longer they'll serve you so fill 'em up when you need them then bleed them back down when you're done. You don't need to be fanatic about it, I put my batts on charge the night before I run so they're ready to go for the morning. If I don't use a battery on a run day I try to discharge it back to storage the same day, but it doesn't always happen.

This is what I've started doing too, besides I ordered a Lipo safety bag, it was cheap for 6 bucks, I should get it today. The bag contains the fire inside the bag, in any case, you just see smoke and that's it.

[bob_eissler]

Rcgroups.com has some good threads about the proper care of lipos and what to look for in a good charger. I am using the new batteries more and have ruined a couple because of a cheap charger. This would be a good subject for a seminar at Carmel if we do them anymore.

[corsaire]

Changing the type of battery a bit....I have a Power Sonic Gel Cell 12V - 5amp, my question to you battery majors - I have a Graupner SPEED 500E 7.2V (came with Dave's subdriver), A Viper Marine Speed controller (supports 12V and up)- Can I use it in my Rc system? I'm planning to use it just as a test battery in dry-dock, not on board, for that I have the Lipo. Tx

[JWLaRue]

Some of my original r/c subs were powered by a Powersonic gel cell battery. They work just fine. In fact, most of us simply placed them in the wet area with little-to-no attempt to waterproof any of the connections. (If you don't you will get galvanic corrosion, but everything still works.)

So other than the already mentioned concern about possibly running too much current through the 7.2-volt motor, use it. Other than a different battery chemistry, it'll essentially be the same as using your LiPo.

Also, how many amp-hours is the gel cell? It may help us to gauge how long your setup should run.

-Jeff

[salmon]

Power Sonic Gel Cell 12V - 5amp

Jeff, would that be the 5amp he mentions here?

[corsaire]

Some of my original r/c subs were powered by a Powersonic gel cell battery. They work just fine. In fact, most of us simply placed them in the wet area with little-to-no attempt to waterproof any of the connections. (If you don't you will get galvanic corrosion, but everything still works.)

So other than the already mentioned concern about possibly running too much current through the 7.2-volt motor, use it. Other than a different battery chemistry, it'll essentially be the same as using your LiPo.

Also, how many amp-hours is the gel cell? It may help us to gauge how long your setup should run.

-Jeff

Yes, 5.0 amp /hr. I already had this gel cell for many years now, but I don't intend to use on board like I said, since it would throw my surface and submerged trim off big time. The idea is to just use it
in dry-dock so I don't spend the Lipo's power in pre-running tests outside the pond or if I just want to do quick rc system tests/adjustments at home.

[corsaire]

I got me also last night this tester for 10 bucks at Sears. I'm using the battery 9V setting (pic) to test batteries - Is this correct or should I use a different setting for more accuracy?
Also, what the proper range would be for a fully charge Lipo 11.1V - 5500mah (3S)?
My Gel Cell 12V - 5 amp/hr rated fully charged at 13.14 on the battery 9V setting in the multimeter, is this correct? Thanks.

[JWLaRue]

Jeff, would that be the 5amp he mentions here?

Hmmmm.....missed the "5amp" when I read it.

[JWLaRue]

I got me also last night this tester for 10 bucks at Sears. I'm using the battery 9V setting (pic) to test batteries - Is this correct or should I use a different setting for more accuracy?
Also, what the proper range would be for a fully charge Lipo 11.1V - 5500mah (3S)?
My Gel Cell 12V - 5 amp/hr rated fully charged at 13.14 on the battery 9V setting in the multimeter, is this correct? Thanks.
[ATTACH=CONFIG]387[/ATTACH]

If I understand correctly, you will want to set the meter setting to be a higher voltage than what you will be testing. What's the next setting higher than that 9-volt setting?

-Jeff

[corsaire]

If you look closely at the pic where the arrow points out at - it only gives you two settings: 9V and 1.5V BATTERY (BAT) setting. I suspect I could also use other settings on it.
Not sure.

[Ralph --- SSBN 598]

I just checked this multimeter specs.

It has only two settings for VDC.
1.5V and 9V.
The meter is made to test individual cells of 1.5v and 9v batteries.

I looked at other meters on the sears site.

http://www.sears.com/tools-electricians-tools-multi-meters/b-1219254101

These meters go up to 600VDC.
Model # 82146 $17.99
Model # 82007 $19.96

When I posted the meter links above, I should have looked at the specs on the meters.
I would have realized that the $9.99 one would not work for you 12v gel cell.
That meter would be fine for 9v of less batteries.
Can you return the meter and upgrade to the next meter up?

Sorry, I gave incorrect information for your needs.

[Ralph --- SSBN 598]

Some thing to consider.
Multimeter.
A multimeter is something you don't miss unless you have one.
I bought my little Radio Shack meter in 1971.
I use it quite a bit.
I use it enough that it sits on the counter in the kitchen most of the time, right next to my camera.
Or it's in the draw next to the front door.

Cars, models, house wiring and other electrical projects.
A multimeter can be your best friend chasing down wiring problems.

[JWLaRue]

I tried looking at the photo on my iPad...but it didn't allow me to enlarge the photo. Now that I'm my PC, I see what it says. I would have used the Vdc side of the dial. I think I see a 20-volt setting?

-Jeff

[KevinMC]

I tried looking at the photo on my iPad...but it didn't allow me to enlarge the photo. Now that I'm my PC, I see what it says. I would have used the Vdc side of the dial. I think I see a 20-volt setting?

-Jef

Agree - Use 20VDC setting for 12V gel cell and 3S LiPo alike. Volts are volts, I'm not sure what's "special" about the battery test setting on this meter.

[Ralph --- SSBN 598]

Looking a the specs on the SEARS site, I think the 20 is in the DC amp section.
The specs only show two setting for testing batteries on this meter.
1.5v and 9v. DC