Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[uboatbuilder]

Hi, any ideas on battery packs for the revell type 7. the dive unit is only two inches wide. ive tried to get in contact with subtech UK but they wont answer my emails. has anybody got a contact number for  subtech uk  please

[dazz]

hi,here is subtechs web site,i have just bought something,dazz
http://www.rcmodelsubs.com/acatalog/index.html

[colin-stevens]

no problem for me, very prompt reply. keep trying

[Mankster]

Lipos are your best bet where space is at a premium. A 2 cell 7.4v pack should do with Dave's WTC's.

[BobF]

Hi Mankster,

I would not recommend Lipos in any area where there is water about. Your sub could end up destroyed after it blows up. NAVIGA the world governing body has baned their use in model boats.

Bob

                  PLEASE IGNORE THIS POSTING, I NOW BELIEVE THE INFORMATION TO BE INCORRECT

[Mankster]

Hi Mankster,

I would not recommend Lipos in any area where there is water about. Your sub could end up destroyed after it blows up. NAVIGA the world governing body has baned their use in model boats.

Bob

I wonder why they banned them? The only known danger with Lipo's is when you charge them wrongly or in severe impact (like when an RC plane with lipo in its nose meets the ground!). Lipo are like any other battery an can be run completely wet. You want to waterproof one of the terminals (to prevent risk deep discharge). In fact one of the safe ways of completely discarging a Lipo (say prioir to disposal, fully discharging will ruin its ability to accept a full charge) is immersing it salt water. My digital camera is waterproof to about to 3 meters and has a Lipo battery, and I hold that up against my face when snorkling (Olympus wopuld be in big trouble if their batteries exploded!). Plenty of people run their Lipo in small submarines completely wet, but in the case of the Dave Welch WTC, there should  space for them.

[colin-stevens]

oy gawd, something else to woorrrrry aboot.
stupid hobby

[BobF]

Hi Mankster,

I have no personal knowledge of Lipo batteries because they are banned. The club was told they expload when wet so  their use was banned. NAVIGA must think there is a problem to have banned them. Interesting that you say this is not the case. I know they are used in aeroplanes to great effect. I am in no way doubting what you say about them, so it's all a bit strange. Even so, I will stick with the nicads in my Revell type 7 Sub.

Bob

PS I did see a Hydro expload after a rapid charge of a Nim pack and then an immediate run afterwards.
Also as most of us know, Nims can go bang if charged and used in a non vented area such as a sub.

[BobF]

Hi again mankster,

Just been having a think etc re above topic. It may be that I have rembered the reason incorrectly as to what the problem with Lipo was, and why they were banned. I've just done a search about the subject, and it revealed problems with the charging of them. Although I can't now find it, I'm sure there was an article about only charging them out doors.

Bob

[colin-stevens]

asked about this in my local shop. the answer was that they love water and air. they go up like a magnesium flare. they only way to put them out is to bury them in sand to cut off the oxygen. he has seen a couple cook of, normally after a mid air collision. unlikely in a sub or boat, but to me it aint worth the risk.

[Mankster]

Yes they have specific charging requirements and you must use a dedicated lipo charger and not charge at a max of 1c. Also  pulling more current than the C rating will cause them to over heat. I fly electric planes and Heli's and have never seen a Lipo fire in 4 years. Like any electrical fire, water won't put in out (won't make it worse either), submerging in water will put in out instantly and so will dumping sand over them.  But they pack big punch for their size, and lithium batteries are now found in everthing from mobile phones to Playstations. If you are disposing of a Lipo battery you can fisrt discharge in by submerging in salt water for a few days and then bin it with normal rubbish, something you cant do with Nicad and NiMH.