I assume the cells came with some kind of plastic covering on them. Most times the cells come heat shrinked. If that's the case you don't need to add any more heat shrink to the cells. I have seen the sells come with only a cardboard wrap. We pulled the cardboard off and put some heat shrink on each cell. The cardboard would have fallen off when wet and shorted out the cells. I put heat shrink around the pack when the 5 cells are soldered together so they stay together.
You're right, the cells already have plastic protecting them, so I just need to use the heat shrink to hold them together? Also, the Mtroniks ESC says that it can interfere with the reception if it is too close to the RX. Has anybody had this be a problem? I wanted to put it in the same drybox as the receiver and other electronics.
Yes the heat shrink just holds them together. If it's the Mtronics Viper Marine ESC I have seen others use it wants to be in the water channeling. I don't use them, but have heard they like to be wet to help disapate the heat. If it's that type plan for it outside of the box.
Tabs you get from tower hobbies. They are under the rc car stuff. I use a 100 watt soldering iron with a 1/4" tip. You need a big tip to hold the heat. Like Bob said heat kills batteries. Also when I build mypacks I CA them before I put the shrink wrap over the cells.
I found a site that carries the heat shrink tubing (radical RC), but the sizes don't go large enough! Has anybody tried making a stick battery? It would be skinny enough for the tubing and actually fit in my ship better, but I'm not sure how to solder them together end-on. My batteries already have tabs, but they might actually get in the way soldering them end on...
OK I found better heat shrink. Is it better to wire the entire power system to both batteries, or have one for the pump and one for propulsion?
It's a risk either way. If you wire both batteries together, both batteries will get drained equally, and you will get the maximum running time out of your batteries. On the other hand, once those batteries run out, both your pumps and propulsion will die at the same time. If you wire one battery to pumps and the other to propulsion, it's a different story. Since you're not draining each battery equally, it is entirely likely that one battery will run out before the other. In exchange, however, you're isolating the systems so that only one fails. If your pumps fail, you've still got propulsion to bring you to shore. If propulsion fails, you've still got your pump to keep you afloat until help comes. Personally, I run my boat with the batteries wired separately. I don't have any main power switch; it's on when I plug in the batteries. Since I have one ESC for propulsion and one ESC for pumps, it's just easier for me. The way I figure, together or separate shouldn't matter as long as you're carrying enough batteries in the first place. If you're running out of power, then carry more batteries.
I've tried both ways of doing this. Bismarck was on seperate batteries because my motor originally was on 12v and my pump on 6v. In Yamato I use 4 batteries but in pairs dedicated to each system. So I had 2 for the motors and 2 for the pump. It worked well that way. Then I saw Chris Osborne's Musashi setup and he just banked all 4 together and seeing how that Monster performed I did the same and been running it that way since. Roma uses just 3 and I banked all 3 with no issue there. I have had one sometimes 2 batteres disconnect but still was able to power in and operate pump and motors. Both systems work well. It depends on your ship and your battling circumstances and your preferences.
I personally like the "all or nothing" approach to batteries. The idea of being dead in the water, knowing there is power on board for the pumps that I can't use for drive is just a non-starter for me. If I went dead in the water like that, I'd sooner shut the pump off and just let it sink then try to survive the vultures coming in and pounding me. Honestly, that damage is simply more patching I have to do, and frankly, patching damage isn't the most interesting part of the hobby. Also, if I can still move, there is a good chance they wont be able to ADD to my damage. So basically, if I run out of juice, no manuever and no pump means I will sink quickly and take less damage doing it. That's a major plus to me.
I have to agree with this. Having all your power in one system gives you more flexability. Some battles you might spend the whole time running around the pond chasing people or whatever and not have to pump much, some you might get in the thick of it from the get go and spend the rest of the battle trying to sit still and pump as much as you can. If you have seperate batteries for different systems you just dont have that sort of ability to react to the situation that you might otherwise have. Sure if that system fails then you sink but thats pretty good incentive to build a system that doesn't fail, relability is one of the most important aspects of any good warship. Also if either your pump or propulsion stop working you stand a pretty good chance of sinking anyway so its not that big of a drawback. The only exceptions I would make would be if you're running different systems at different voltages.
In terms of reliability I favor all in one power as opposed to seperate. I never had power issues for any system this way since I coverted to this method. When I had sperate systems I found either one system or the other would run low on battery power. If I lost drive that's fine but if I was heavliy damaged then I need more pump endurance power to maintain full stream. If the pump battery was weak I couldn't tap into the drive batteries to stay afloat. Bismarck sank like this against Houston. One hole in the bow on Bismack and the pump batteries died on me before the pump got going. They were old anyway but that was embararrasing say to least. Point is if I had tied in the drive batteries the pump would have saved me.
That sounds good. Is there any drop in power to the drive motors when I switch on my pump? That could make calibrating the speed hard...
There can be a drop in speed if the pump is working (i.e. pumping water). A pump motor can draw a lot of amps (Dependant upon the pump motor type). Mine can draw enough to heat up number 12 wire under full load. Such a draw will lower the voltage of the main battery supply. However, you generally will not have much water in the boat during speed trials and an unloaded pump will draw less than an amp. Marty
I run my system all banked together also. I have seen a lot of 7.5 pump batteries fail after a work out. If I was running two different voltages I would still use the main system to pump the voltage (series parallel). Something is better than nothing....
It seems like it would be a pain to make less speed when the pump in working, particularly in combat... Does it slow down with an ESC, too?
when the pump is working most of the time you wont be going full soeed becouse you have damage and the faster you go the more water will rush in . so its like stop and pump go stop and pump go and so on most of the time
yes, the slow down is due to the drop of the voltage at the battery when it is drawing a lot of current. note the difference in voltage at the battery when anything is running vs. when nothing is. The difference is due to the internal resistance of the battery. Marty
Do most people install Deans connectors to their batteries? My charger uses the big white type, so I would have to change its connector.
