Category Archives: Batteries and Chargers

Batteries for Beginners 4 – Chargers!!

I’ve only been radio sailing a short time, but I’ve already had five chargers in the house. Or is it six? My wife thinks I am/we are mad. However, it does give me a disproportionate amount of experience in the matter (ha!).

Let’s start with safety though. It appears that LIPO batteries in particular (see earlier articles) cause some safety concerns and prime among them is what happens if they leak, or overheat, or leak and overheat. There is honestly a lot of opinion written about this online. I feel my own summary is that your batteries can leak and become dangerous from three or four main reasons:-

physical damage, bumps, abrasions etc (check them visually regularly)

exposure to extremes of heat or cold (so don’t let it happen)

over charging (includes left on the charger overnight – my favourite)

amazingly, apparently letting the charge drain to nothing also can cause problems

What do you think? It seems to me that at least the first three above are high in my mind, but surely the most likely thing I am going to experience is over charging, or perhaps charging too fast (too high a current included).

So we have had five types of chargers here in just a few months. Let me deal with that. Firstly, rechargeable AA batteries for the transmitter. Well you could simply always carry a spare pack of duracells in your pocket, but I disposed of the first charger because it had no display or coloured light system too show when your AAs were fully recharged. So now, I use one with a display that shows you the state of charge in each cell, plus flashes at you once it hits full. It’s a pity they dont beep when full as well. From Amazon, not expensive, and great. It came with fresh AA’s I think. It can charge different sizes too, and variable battery numbers.

Now… on-board batteries ….. much more interesting….

You need to read up about balancer cables and balancer charges. Basically, if you just charge via the one main connector, in a two cell battery the first cell hits full before the second cell. It obviously leads to all sorts of inequality but notably the first cell will tend to over-charge and over-heat. So get a charger that supports balancer leads.

In my short time, I’ve had LIFE with JST connectors, LIFE and LIPO with XT connectors. The first charger I had for the JST batteries, was frighteningly crude. You plugged the battery in for hours, and it never seemed to charge fully. It had one red warning light. It was with the Club loan boat – I threw it out and bought them a new one.

My brand new IOM came with LIFE batteries XT60 connectors, …big ones. The charger had balancer leads (the little white things with three holes), progress lights in red and green, so somewhat more informative. It had no indication of applied current though. I think it did one battery at a time – I’d have to check. Then I got the Marblehead which came with XT30 connectors, …the mounting variations made my head hurt. I have a mix of LIFE and LIPO for that boat just so I can make my own comparisons.

So what to do?… Consult an expert…. I paid a visit to the fabulous TJD Models shop in Sutton at Hone, Kent. (near M25 and close to RC Yachts, home of the DF95) Not sailors, but drones, planes and race cars is their thing. They were magic. Seen it all before and knew the questions to ask.

First question was all about connectors, and the second big discussion was about charging current. He asked what m.a.h. batteries we use in sailing. I said (guessed) 1000mah to 1800mah. He said, always charge at 1 amp maximum else they get hot. His simple rule was to show me a 1500mah battery on his desk and cross out the last three digits and you get a “1”. Use 1 amp was his strong recommendation for both longer life and safety.

Then he asked about budget. I’m sure you can spend a fortune, but his product shelf went from basic to intelligent, and £25 to £50. What price safety? I know £50 is double £25, but honestly around here that’s about 6 cups of latte. With their help, I chose a charger model around £50 (a bit less I think). I bought the SKYRC 100 intelligent charger in the photo above. I bought two eventually – one for the loan boat and one for me.

For your £25 extra, what do you get?

-firstly it has separate charging regimes for LIPO LIFE and about three other battery types, I’d never heard of. So I share my one charger across all boats and batteries now.

-when you plug in, it checks the battery type and tells you what it thinks you have got, so the user can check for mistakes.

-you select the amps going in, the number of cells, the target volts you want, and it displays all this all the time during charging. You particularly see the current amps fall as “full” gets closer.

-when it detects “full” it turns off the current and beeps like hell at you to come and unplug everything. You can hear it from two rooms away. I love it. I disconnect straight away.

-it has balancer lead support and refuses to start unless you plug it in. Good.

-get this, it can charge two battery types! I have it set up to do XT60 in one socket, and XT30 in the other. (see photo). I’ve not thought, but it probably can charge two batteries at once (I’d have to check)

For my batteries with JST, the lovely TJD Models Shop made up an adapter lead while I waited. For XT30 (my marblehead) batteries I bought this little bag of adapters for about £5.50 on Amazon.

So there we are – do what you feel is right. I wanted to feel good about managing my risk, and for the moment this charger plus fire-proof bags seems as good as it gets. To charge I place the SKYRC unit inside the explosion proof bag (fits nicely) and charge inside there. The cable goes in through that little trap door flap in the side that you can see here. Easy…

Batteries for Beginners 3 – Connecting Your Battery To Your Boat…!

Hopefully your new boat comes with batteries and is all set ready to go. Your battery is in top condition?!

What if it isn’t?? What if you anyway decide to treat your new boat to some new batteries!!??

Well, a big barrier to get over right away is the answer to “What Connector?” . When you go battery buying you’ll hopefully see that you can select the type of connector you want (£), or if you are unlucky enough to find they only list a connector that you don’t want, then call them. For a few pounds, you’ll eventually get the battery-connector configuration that you want.

Can you look at the photo above…. that’s the One Metre I borrowed to get started. I adored that boat.

Can you see that tiny flat little red connector? I think it is called a JST (“Japan Solderless Terminal”). The part you see is the female half, so the red male part is really tiny. I have a feeling that it can carry a current of 5 amps maximum, but I may be misremembering and it’s less than that.

The in-thing in the world of radio sailing connectors seems to be XT connectors. I’ve only been sailing a short while and I already find I have two connector types. My Marblehead has XT30 and my One Metre has XT60. So what is going on?

The XT60 connector on my One Metre.

The XT30 connector on the Marblehead.

The ratings for these connectors is 60 amps maximum on XT60 and 30amps on XT30. The other real world difference is that the XT60 is a jolly sight easier to plug and unplug – big fingers, small plugs….

What’s going on ?

Honestly in that ten year old boat I borrowed I never once thought I couldn’t sheet in fast enough. So what’s happening? Well, bigger is better and batteries can indeed pump out more amps at a time than they did ten years back. Batteries are improving very quickly. still – if you stick 30amps up your finger you’ll get one hell of a tickle, not to mention 60amps.

Did you read Paul Elvstrom’s “Expert Dinghy Racing” when you were growing up. There’s a story in there about winning a race by throwing in rapid gybes in succession on the run to accelerate the boat. The eagle eyed amongst you following the 2023 IOM European Championship will have read that the winner was doing the same thing as Elvstrom. To do this he had a bigger drum on his sheet winch, so that he could throw the boom across quickly. To drive the bigger drum… you need more current. You may indeed need LIPO capability aboard but your connectors need to handle it safely. So this may be a strategic direction of travel !!

Anyway, each of my two boats has XT connectors of different sizes.

  • so my batteries need to be dedicated to each boat….
  • when I buy my batteries I need to be careful to buy the correct connector ends. I’m told they are very challenging to solder yourself (see YouTube). Things change all the time, but when I bought Overland LIPO batteries the connector was a simple drop-down option on their website. When I ordered LIFE from Vapex, I had two ring them up to get the connectors I needed put on before purchase.

Why might we not have XT60 ready on the Marblehead – weight weighty weight !!

There are also implications for how you charge batteries with differing connectors. More about that in the next post!!

So think ahead! Good luck getting into this one!!

Batteries For Beginners Two – Storage Bags…!

In our last article about Batteries in Radio Sailing we talked a little about safety and fire risk.

Look in this photo above. There is a bag within a bag. They are both made of the same type of weird robust material. The inner bag is like a simple envelope with a velcro sealed over-flap. You’ll see simply loads of people using exactly this bag design to store their batteries. My little pouch bag will take three IOM batteries, then it’s pretty much full. The cost of the bag is minor.

I figured I needed more than one bag as there are more than three batteries here at home. The outer bag in the photo is more like a small picnic hamper with a zipper lid. It was about £15 on Amazon. I keep everything in there really. £15 compared to the cost of fire damage or your marriage breaking down is trivial. Buy one or more. I keep a bag within a bag because then I worry less.

Amazon claimed the outer bag was “explosion proof”. What I really liked about the Amazon bag is that it has a little port in the bottom so that you can get a charging cable in – and charge the battery INSIDE the explosion proof bag. I’m going to write some more later about when you are at peak risk … and while you are charging is about the highest and most regular risk you have.

Just get a bag and try it.

See what you think.