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[waverunner]

The battery packs the model shop supplied with my boat are Overlander 3800 9.6v sticks which give me about 10 - 12 minutes run time. I see Overlander do 5000mAh sticks which should up the run time by perhaps 3 minutes but I'd like longer if possible. I've trawled the net but can't find anyone offering more than 5000mAh. Does anybody know if larger capacity are available?

Many thanks
Jim

[DickyD]

http://www.component-shop.co.uk

http://www.component-shop.co.uk/html/body_large_packs.html

9.6V 5000MaH NiMH largest I could find I'm afraid.

[waverunner]

Thanks for the link and that's a really good price too. The equivalent Overlanders are considerably more (but they also look remarkably similar so I could swop them without SWMBO noticing  ).

Does anyone have experience of their products? Difficult to resist at that price.

[Netleyned]

Good gear
Fast service
Cheapest postage around

No Connection just one of many satisfied customers

Ned

[DickyD]

Loads of the guys on here use them Jim.

Their service is excellent and their prices are cheap.

Delivery is quite often next day and their P&P is cheap.

They now have a phone number which is not on their web site for some reason.

0845 1309967

[waverunner]

Ordered and delivered exactly as promised and in time for the weekend.

Thanks for the heads up

[john s 2]

I have found that despite the makers claims. The capacity of the cells is often less than stated. This applies
more to the higher capacity batteries. Discharge rates if high can result in less capacity than expected. John.

[HS93 (RIP)]

if you want GOOD  batteries and are prepared to pay try   http://demonpowerproducts.co.uk/index.php?cPath=46  I have been buying of him for 35 years but they are not cheap

peter

[essex2visuvesi]

if you want GOOD  batteries and are prepared to pay try   http://demonpowerproducts.co.uk/index.php?cPath=46  I have been buying of him for 35 years but they are not cheap

peter

Bloody hell is he still going? Used to buy my RC car stuff from him back in 80...*Cough*

[HS93 (RIP)]

yes Nick is still going and if you bought of him in the 80s you will prob have bought one of his amazing speed controllers and he sold more batteries than the rest combined, prob because he was the importers, nice bloke, did you ever race against his wife?

[essex2visuvesi]

No that I remember.... but then it was a good few years ago.  I used to race an Associated RC10 and later a Schumacher Cat. My dad would take us to his shop every few months for supplies.  It was quite a drive as we lived in Essex back then but he was so much better and cheaper than our local one.
What was the name of the speed controller? demon speed controllers ring a distant bell

[HS93 (RIP)]

yep Demon speed ctr, I still have a few and a brand new cat I raced 12th scale so even drove a demon car at one time.

[hmsantrim]

 Hi Wave runner.
                        this lot do 10amps in a D cell if you could squeeze then into  yer boat but only 5amps in a c cell.

http://www.vapextech.co.uk/acatalog/High_Power_Consumer_Batteries.html


                                    cheers frank

[waverunner]

I have found that despite the makers claims. The capacity of the cells is often less than stated. This applies
more to the higher capacity batteries. Discharge rates if high can result in less capacity than expected. John.

Funny you should say that as I ran the boat yesterday with both the 3800s and then the 5000s and didn't notice much difference in run times. Probably didn't help that the batteries were very cold so roll on the warmer weather.

[waverunner]

Hi Wave runner.
                        this lot do 10amps in a D cell if you could squeeze then into  yer boat but only 5amps in a c cell.

http://www.vapextech.co.uk/acatalog/High_Power_Consumer_Batteries.html


                                    cheers frank

Thanks Frank for the link. I'll have a measure up and see what I think 

[waverunner]

Didn't have much time yesterday evening but gave the boat a run on one of the 5000 packs. Run time seemed reasonable but it was almost as if the voltage dropped after a few minutes.

One question on these battery packs. After running them in the boat should you let them rest/cool down before recharging or doesn't it matter?

[grasshopper]

If you want more performance - I think the Ni-mH cell has had it's day, Go Li-po with brushless motors
Despite all the dissenters, they are proving their worth in terms of power and light weight over all other sources of energy for model use - almost including the internal combustion engine..

And before you say it - Buying the proper charging equipment to match these cells is not that expensive either - my £90 do-all charger has been superseded by a better product for less money!

Any interested parties might do well browsing through HobbyKing's website - but make sure you via their German warehouse..
http://www.hobbyking.com/hobbyking/store/index.rc

[waverunner]

  for the suggestion but I know nothing about Lipos and in fact have been put off by a few people I know.

If I was to go that route it seems a lot of work and expense changing batteries, charger, motor (which I presume will have to be water cooled?) all for a few minutes additional run time. If I wanted to up the performance then yes I guess I will have to go that way.

[tigertiger]

I think I read somewhere that bigger amp batts heat up more, and this is where a big chunk of the 'extra' energy goes.
But I might be misremembering.

Moving from a C to a D may upset the trim/balance on fast boats, due to extra weight.

[grasshopper]

There's no necessity to upgrade motors to begin with...the power to weight ratio of Li-po's just means you can pack a lot more energy into the same boat or benefit from the lower weight.

There's no 'black art' involved here, just common sense - Li-po's can be a real boost in performance and the price is becoming less of an issue. It's got to be worth investigating before discounting it, I'd heard all the 'horror' stories and was equally sceptical but have now fully embraced the new technology.

As regards your option of moving up to a 'D' size cell - just check if you decide to go that route that the cells you are thinking of buying are capable of high discharge rates, not all cells are designed for some of the serious abuse we modellers give them.  Sub 'c' cells are often designed for high cyclic use where other sizes are not.

[waverunner]

I'm not sure D cells are an option due to the extra weight and size.

Lipo's seem to go from 7.4v with the next option being 11.1v. I'm running 9.6v at the moment with a Speed 600 motor that I understand is maximum either 9.6v or 10v. Looks like the Lipo will require a motor change. Given that I've just bought another couple of 9.6v C packs I'll stick with them until I've had my moneys worth and then look at switching to Lipo.

  for the help.

[grasshopper]

The motor voltages are a recommendation and bearing in mind that some batteries under load drop a couple of volts you're probably not running at the recommended motor limit for very long. If you were to run it at a higher input voltage with the present motors then going down one size on the props will allow for the higher rotational speed and help keep the increased current draw down as well.

Whatever you decide to do, best of luck with it. Just didn't want you to limit your options because a few have had a bad experience.

[tony23]

Hi Waverider,
                   The future in battery's for modelling I don't think is Lipo's the battery's are too expensive plus they cannot be boosted quickly my club will NOT permit them to be even charged in the club house so I for one would not leave them on charge up the workshop.
Look into the new A123 battery's they are Lithium Ion Nanophosphate technology these are used in all the latest Makita and Dewalt tools they are absolutely bomb proof you can draw as much as you want from them and better still can stick 60+ amps into them without damage to charging them in minutes.
Check them out for sale here http://www.acemodel.co.uk/batteries/a123-lifes04-/cat_45.html  when they first came out they were quite big but they are now much smaller and even flat packs you would need 3 cells to make a 9.9Volt pack

I know it's nothing to do with modeling but this shows there capability http://www.youtube.com/watch?v=qcvmvrmTMMk

[waverunner]

Very interesting but they don't seem as yet to have nuch in the way of capacity. Will keep an eye out though as I guess its only a matter of time.

 

[AlisterL]

I would second Grasshopper's suggestion regarding the LiPo's. I have made this move recently for my PT boat when the 9.6v pack I had died on me. I couldn't replace it for less than NZ$70 and they were very hard to find, but LiPo's are everywhere - I got two 11.1v 2200mAh for NZ$30 each. I think one of the reasons that LiPos have had a bad reputation is due to the chemistry in early examples and how physical damage can compromise their integrity. The other thing is that LiPos can discharge at very high rates continuously and in the case of a short that can mean a heck of a lot of current in a very short time - which we should protect against.

In order to make the change I got a new charger (Turnigy Accucel 6), 2 LiPo's (Turnigy 3S1P 11.1v 2200mAh) and a charge bag. I charge the batteries in the charge bag as it is fireproof (supposedly!). The Accucel 6 seems to be a good charger, but is limited to 50 watts maximum, so larger voltage or capacity battery packs cannot be charged at their C rating. It does, however, have all the balance ports built in - up to 6 cells. I cannot recommend enough that, if you choose LiPo, you get a charger that will balance the LiPo pack as it is charged - this will prolong  the life of the pack and your run times. I charge my 2200's at 2200 - they do not even get warm - not even slightly. I recently purchased a voltage monitoring doodad too - my biggest worry about these things is over-discharging them and causing damage that way.

One key thing, IMHO, is to be physically careful with LiPos - do not overdischarge (get a battery monitor that buzzes and flashes when the voltage drops below 3v/cell) and inspect after each use. Do not drop, hit, bend or deform them in anyway. If there are signs of physical deformity then do not use them again. Treat them well and they will reward you.

As for changing connectors and motors, you will likely need some sort of connector converter for the battery to the ESC (or change the connectors on the ESC), but if you are talking about the difference in current draw between a 9.6v and an 11.1v battery, well, I wouldn't have thought it would be significant, and I would not think that as a result you would need to change connectors - assuming that they are appropriately sized anyway. Take the usual precautions with fuses in all the right places and you should be fine. I did not change either the ESC or the motor in my PT boat.

One advantage that you will get from the LiPo's is the ability to buy packs that are built in parallel - I better explain that a bit. My packs, as mentioned, are 3S1P which is three cells of 3.7V each linked in series. A 3S2P is a total of 6 cells, arranged with two lots of three cells in series and then each series packs are then linked in parallel - which gives the same total voltage, but doubles the capacity or C rating, and all in one nicely wrapped bundle.

As usual I have typed out an essay when probably a few words would have sufficed...