Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: bazcarp on March 18, 2011, 04:24:35 pm

Title: 6v 4.5 ah sealed lead battery
Post by: bazcarp on March 18, 2011, 04:24:35 pm

anyone please advice as to the running time of this battery in a bait boat,thank you.any rough ideas will do.

Title: Re: 6v 4.5 ah sealed lead battery
Post by: john s 2 on March 18, 2011, 08:25:04 pm

A basic way to get an idea would be to run your boat in the bath at near full speed. Starting with a fully
charged battery of course. This should give you a rough idea of the time. Make sure if doing this that the motor
does not get to hot. John

Title: Re: 6v 4.5 ah sealed lead battery
Post by: bazcarp on March 18, 2011, 11:19:24 pm

thanks

Title: Re: 6v 4.5 ah sealed lead battery
Post by: malcolmfrary on April 02, 2011, 08:01:58 pm

Quote from: bazcarp on March 18, 2011, 04:24:35 pm

anyone please advice as to the running time of this battery in a bait boat,thank you.any rough ideas will do.

Depends mostly on the motor(s) and prop(s).  Measure the current draw under load, then you divide the battery capacity (4.5 in this case) by the current, and you get the duration in hours, or fractions of.

Title: Re: 6v 4.5 ah sealed lead battery
Post by: johno 52-11 on April 03, 2011, 11:11:24 am

Quote from: malcolmfrary on April 02, 2011, 08:01:58 pm

Depends mostly on the motor(s) and prop(s).  Measure the current draw under load, then you divide the battery capacity (4.5 in this case) by the current, and you get the duration in hours, or fractions of.

The capacity of an SLA that is quoted is for a discharge over 20 hours or at 0.05C that in this case would be 225mA if your discharge rate is higher then you will only get part of the stated capacity. If your motor is drawing 4.5 amps or 1C then you will only get just over half of the stated capacity in this case about 2.6amps or just over 30mins running time.

There is a technical document for different sizes of battery at the bottom of this page that will give you more informationhttp://www.yuasabatteries.com/industrial.php (http://www.yuasabatteries.com/industrial.php)

Title: Re: 6v 4.5 ah sealed lead battery
Post by: Peter Fitness on April 03, 2011, 11:02:47 pm

I use these batteries extensively in my models and usually get about an hour's running at half throttle. This gives a realistic speed for the type of boat I sail. Using full throttle reduces the running time to less than 30 minutes in most cases. It's not a good idea to run them flat, as SLAs don't take kindly to being fully discharged. When the boat starts to slow down, I head for the shore.

Peter.

Title: Re: 6v 4.5 ah sealed lead battery
Post by: brianB6 on April 03, 2011, 11:47:56 pm

Also remember that like all acid batteries, SLA's should be kept charged during storage.
I put mine on the charger every couple of weeks but I have one SLA 6v 4.5A that was accidentally left in a cupboard for 3 years and is still going.