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[Mezza50]

I've been tempted to build another boat recently but have decided instead to upgrade the performance of the one I have already via a new battery set up.

My current boat has 2 Graupner Speed 700 Turbo 9.6 v motors. The props are 3 bladed, approx 35- 40mm diameter
The ESC is a Electronize FR30HX - 30amp continous current limit, 200amp. motor stall rating, 6-24v Input.
It is powered by a 12v 7amp SLA battery.
The hull is approx 48" long and is what I would describe as a patrol boat type hull without the hard chines.

What replacement battery set up can anyone recommend for me? Just like everyone else I'm after a bit more performance and a longer running time.
I know battery technology has moved on, hence the question.
Many thanks,
Chris.

[Subculture]

Either Lithium Polymer or A123 Lithium Iron Phosphate batteries would be my choice.

[Mezza50]

Thanks for that swift response. Is there a particular Lithium Polymer set up you would recommend? I'll do my research on the web but I've no idea what the equivalent Lithium Polymer battery would be to replace a 12v 7amp SLA.

Thanks.

[Roadrunner]

given your current battery size, 12v 7ah ,.. there quite heavy 2.4kg last time i checked, the likely hood of getting longer run time with the current battery is slim, as for lithium's, not quite sure there up to the job.


The way to incress performance is to change to larger motors, 800-850 or bigger sizes will incress performance but your still looking at running with LA, you could just look at a higher AH of LA , say a 12v 12ah or possibly a small 24v battery will do the job.

Be honest with yourself though, performance comes at a cost of £30-50 per 800-850 size motor or upwards of £100 if you get the real large beasties. adding more weight in a larger battery will decrees performance as extra weight will be added.

Is it really worth spending x amount of cash for little change in performance?

Or is it worth just changing the motors to larger sizes, and keep the battery as is, and carry spares with you for the lake days out?, you obviously transported the boat in a car, im sure there's room in there for a few extra battery's.

[Mezza50]

I've just googled Lithium Polymer batteries and found postings on the RC Groups forum re Li-Po batteries that have scared the s*@t out of me.
Fire, Explosions, smoke, RC cars exploding, Boats sinking, difficult charging regimes etc, I could go on ...

Based on the above I've now decided to stick with what I have and buy extra SLA batteries as Road Runner suggests. Any money saved is now going into the Graupner Cap San Diego fund!

Thanks for the advice everyone - off now to source some SLA's.

Chris.

[Roadrunner]

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

here SLA Cheap, quick delivery and no P&P rip off!

[Subculture]

as for lithium's, not quite sure there up to the job.

In what respect?