Parallel batteries discussion - Page 2 - RC-Monster Forums

MetalMan · 12.15.2005, 09:32 PM

As far as I know, there isn't an expiration date for the 5%. Or at least I hope not, since I have 3 of these "gifts" :L:.

You know, I can't seem to think of any other application that uses parallel batteries either. Usually with things outside of RC, if you need a higher capacity battery, then you get a larger one. In RC, though, that isn't always feasable (especially with 8000mah batteries!).

BrianG · 12.15.2005, 09:49 PM

Quote:

Originally posted by MetalMan
...Usually with things outside of RC, if you need a higher capacity battery, then you get a larger one. In RC, though, that isn't always feasable (especially with 8000mah batteries!).

Exactly, which is why I started thinking about this in the first place.

So, do you get a 5% after every 50 posts, or is it something like %5 after 50, another 5% after 250, 500, and so on? I'll probably never get that high as I don't have that much information to impart, but I'm just curious. :)

Sylvester · 12.15.2005, 10:17 PM

Well, you get 5% on your first 50, than i think its another 5% at 100, than another 5% at 200 or 250, i dont remember, and after that you get 500 post and you get another 5%, and you cant post till 500 posts and add up all the %, only 5% off each order max. ;)

jhautz · 08.05.2006, 09:20 PM

I know this is old.... Do they still do the 50 post discount?

BrianG · 08.05.2006, 09:53 PM

I'm not sure about the 50 post milestone, but it appears there aren't ones for the 100, 200/250, or 500. I got an email and a PM from the site when I hit 50.

squeeforever · 08.05.2006, 10:12 PM

Just wait till you hit 2,500 :D.

go4gold · 08.05.2006, 10:39 PM

BrianG, you don't have to find a dump truck. The dodge trucks with a cummins have 2 12v batteries.You're looking way to deep into this imo.Theses things are supposed to be fun.

JThiessen · 08.06.2006, 12:31 AM

Quote:

The dodge trucks with a cummins have 2 12v batteries.You're looking way to deep into this imo.Theses things are supposed to be fun.

Yeah, I've got two sitting out in my 06 right now that I wont need until I get the dang thing running again. Aint the trucks fault - trying to install power module(s) and new digital guage/module controller system. Some electrons somewhere arent going where they are supposed to be! :035:

BrianG · 08.06.2006, 12:40 AM

Quote:

Originally Posted by go4gold

BrianG, you don't have to find a dump truck. The dodge trucks with a cummins have 2 12v batteries.You're looking way to deep into this imo.Theses things are supposed to be fun.

You know, when I first read your post, I thought: "What the heck is he talking about??" I had to re-read the whole thread. Notice the dates on the posts? jhautz just dug up this old thread probably from a search about post count and the coupons you get. :dft012:

At any rate, this things are fun (for me). Discussions like this can stimulate thought and just might help someone else with a similar question. I guess it's just a little more "geekiness" coming through. :)

BTW: I am almost positive that even those trucks use high current diodes to isolate each other and prevent cross charging. Hi-power autosound systems use them (isolators) when running multiple batteries as well.

coolhandcountry · 08.06.2006, 08:29 AM

There is no diodes on them brian. It is a straight wire from one battery to the other. Same thing on a tractor trailer with more batts. I have seen up to 4 batts in series. I not sure what you mean by cross charge. If a battery is 12.6volts and the other is 12.4 volts you start the car or truck it will draw more from the higher volt system. After the vehicle is running it charges the lowest one first and then brings both up equally. If you want a pic I can get one off brother in laws dodge :D

BrianG · 08.06.2006, 03:26 PM

For car/truck batteries, the cells would have to be exactly the same voltage. Otherwise current would flow from the higher voltage battery to the other. This "charging" current would only be limited by the gauge of the wire and the battery capacity.

CHC, you say there is a wire between them. Do you mean in a series chain? Is it a 24/36v starting system?

coolhandcountry · 08.06.2006, 06:52 PM

They are wired in parrallel form. Not series. I have seen some truck with 4 patts wired 2 parralel each but when trying to start it they are 24 volts to starter. I not sure how they do that.

08.07.2006, 05:54 PM

Most vehicles have an isolator on 2 battery systems... one or both generally powers the starter, but then, there's one battery for the lights or accessories, and the computer.

I know that the Ford diesels will not run properly with less than 14V average voltage...

As for getting a high voltage starter setup... You need a few relays and/or solenoids, and problem solved...

I know for towing a trailer, my dad had a continuous duty starter solenoid (85 amp maximum current) so the truck's alternator would charge the trailer, but as soon as the key was shut off, the trailer was effectively disconnected from the trucks electrical system without unplugging it.

Those relays work great for high power lighting too...

natrix · 10.25.2006, 11:08 AM

I know it's a little old, but I wanted to drag this one up. When connecting batteries in parrallel, is it still safe to assume that both packs must be within .05 volts of each other? And when charging the packs, can you just use the same harness used to parrallel them and charge at 1C?

MetalMan · 10.25.2006, 04:37 PM

Quote:

Originally Posted by natrix

I know it's a little old, but I wanted to drag this one up. When connecting batteries in parrallel, is it still safe to assume that both packs must be within .05 volts of each other? And when charging the packs, can you just use the same harness used to parrallel them and charge at 1C?

0.05v difference is okay for paralleling packs.
You can charge them in parallel, but if you're not using balancers, then it would be a good idea to check the cells' voltages.