By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Dremel

Batteries

7.2v nihm

All Topics | Latest Posts

Search for:  in Thread Title in  
BRYAN ASTON17/02/2019 15:46:19
230 forum posts

greetings all

I have just spent six months on a off in hospital and have obviously not been down the pond sailing my scale boats, however I now intending to resume to when the weather warms up,

my question is this, as my many 7.2v NIHM batteries have have not been charged up for many months are they likely to have deteriated and will not hold a charge.

I don’t want take a boat down the pond and find the batteries only last for a few minutes .

Bryan

Dave Milbourn17/02/2019 16:15:02
avatar
3542 forum posts
218 photos

Bryan

Some cells will be OK while others may not. A lot depends on the state of charge you left them in and under what conditions they've been stored. I'd advise a slow-charge and then, if you can, check the voltage across each individual cell. If you push a pin through the heat-shrink you can find a contact where the cells join. Any cell showing much below 1.2v should be regarded as suspect.

If all seems OK then several slow discharge/recharge cycles will do them good. By "slow" I mean less than C; C being the capacity without the H bit e.g. a 3300mAH pack has a C rate of 3300mA. I usually charge my NiMH packs at approx C/10 for 14-16 hours.

Glad to hear you're out and about again.

Dave M

BRYAN ASTON17/02/2019 16:38:13
230 forum posts

Thank you Dave

They were mostly fully charged before I changed my address to the local hospital, I will take your advice and slowly charge them up again.

regards

Bryan

Dave Milbourn17/02/2019 17:37:15
avatar
3542 forum posts
218 photos

Bryan

Before you do that, you might discharge each pack until the total voltage is about 6.6v - no less. Use a car bulb or similar as a load. Once the voltage gets below 7.2v it starts to drop quite rapidly, so do keep an eye on it! Then slow-charge the pack as described.

Dave

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Boats? Use our magazine locator link to find your nearest stockist!

Find Model Boats!

Support Our Partners
Shrek
Pendle Boilers
Premier March
Premier Thursday
Sarik
JSB MODELS
Shopping Partners
Social Media

'Like' us on Facebook

Follow us on Twitter

Pin us on Pinterest

Member Contributions
Distributors of Model Boats for our overseas readers
Highlights

Make sure you never miss out on the latest news, product reviews and competitions with our free RSS feed

Make your own contribution to the Website

We welcome well written contributions from Website members on almost any aspect of Model Boating with a particular emphasis on practical hints, tips, experience and builds.

In order to maintain a consistent standard and format, all suggestions should first be sent to me by Personal Message for approval in principle. Only a very limited amount of time is available for editing contributions into a suitable format for placing on the website so it is important that the material is well presented, lucid and free from obvious spelling errors. I think it goes without saying that contributions should be illustrated by appropriate photos. I shall be happy to give advice on this.

The Member Contribution area offers space for short informative mini articles which would not normally find a place in Model Boats magazine. It is an opportunity for Website Members to freely share their  expertise and experience but I am afraid that virtue is its own reward as there is no budget to offer more material recompense!

I look forward to receiving your suggestions.

Colin Bishop - Website Editor