Replacement Batteries - Page 1
Forum section: electronics / general

author: Espada
author_rank: Newbie
timestamp: October 27, 2017, 05:35:12 pm
content: I look after some old fencing score boxes and we have a few which are somewhat dated in the tech they use, whilst I am not looking to fully upgrade all of the parts, the batteries used are of the 6v square box type which are mostly zinc carbon and are quite expensive to replace. Each box takes 2 batteries (connected in serial) so giving a nominal voltage of 12v and around 7Ah.I would like to replace these with something rechargeable, I have looked at a few options and was looking for some ideas and or corrections from knowledgeable people than myself. The options as I see them are:Lead Acid 7Ah UPS type batteries which are already used in other fencing boxes (of a different make) so they would be interchangeable and I believe have a more stable voltage than the old ZCs, they are also easy to charge and fairly cheap. The disadvantages are, weight, size would mean they have to run outside of the score box so would be more hassle to set up. Transporting to and from the venue to be transported would also be a pain.3x18650 Li ion cells, these could be internal and would probably be the lightest option but we would also need to buy chargers and prices are also quite high.Any suggestions welcome.Espada

author: Towger
author_rank: Super Contributor
timestamp: October 27, 2017, 08:48:41 pm
content: Photos showing the unit and space available would be useful.First off, I assume a short is created between the contestants to count a score.Would the much lower internal resistance of rechargeable/lipo vs zinc carbon cause a problem with these older units?

author: Espada
author_rank: Newbie
timestamp: October 27, 2017, 09:50:42 pm
content: Hi thanks for that, the method detecting a hit is a little more complex, basically though there are three modes for the box, one for each weapon typeFoil - circuit normally closed until a hit is made, this opens that circuit but closes another between the blade and a metallic jacket worn by the opponent, if this second circuit is not closed a separate light comes up.Epee - circuit normally open, if a hit is made the circuit is closed and a light comes up unless the guard is hit on the opponents blade which also completes a second circuit, if this is the case no light comes on.Sabre - this is the simplest option a current runs down the blade, and into a metallic jacket worn by the opponent which brings a light up.That is a very simplified version of what goes on, it is all micro processor controlled. They do all have a rudimentary 12v input which connects to the battery connectors directly with only a diode to protect against reverse voltage.Size wise the available space is equivalent to the two 6v lantern batteries.

author: amyk
author_rank: Super Contributor
timestamp: October 28, 2017, 04:39:11 am
content: Quote from: Espada on October 27, 2017, 09:50:42 pmhttps://www.amazon.com/UPG-D5897-Lantern-Capacity-Terminal/dp/B004EZLZGA

author: Zero999
author_rank: Super Contributor
timestamp: October 28, 2017, 08:52:51 pm
content: Quote from: amyk on October 28, 2017, 04:39:11 amGood except:QuoteTry this:http://www.ebay.co.uk/itm/Camdenboss-Battery-6V-PJ996-Lead-Acid-BEL060040S/371317352988?epid=1526756688&hash=item56743d2a1c:g:CJwAAOSwfi9ZqHc2Only 4Ah, so it won't last as long per charge, but at least it can be recharged.