battery sale SLA types

[ashley needhamParticipant @ashleyneedham69188]

All. Maplins are sale-ing their 6v 4.5Ahr SLA gel batteries for £3.99. Something of a bargain, and the most usefull size for boating. I am homogenising all my boats (at 80 degrees) to use these batteries, so I only have to carry one size spare around.    Ashley

[Paul TParticipant @pault84577]

Nice one Ashley

Just placed an order for a few and got free delivery.

Happy days..

Paul

ps isn’t homogenising an offence under the cruelty to models act

[ashley needhamParticipant @ashleyneedham69188]

Paul. I deny anything, and there are no pictures on my hard drive…..

It looks like you`n`me are the only ones to benefit at Maplins.    Ashley

[ashley needhamParticipant @ashleyneedham69188]

grab a bargain

[david the newbeParticipant @davidthenewbe]

hi all

i have got a 6v 4.5 ahr sla from maplins can thay be charged with a car charger that has a 6v setting

dave

[shipwrightParticipant @shipwright]

Just a word of caution – SLA's (and other rechargeables eg NiMH, LiPo) have to be regularly maintained by a regular charging programme and use of a charger designed for SLAs. I purchased a 12v 7ah sla via the internet and I was not ready to try it out for about 6 months. When I came to charge and use it I found that it had virtually no capacity (ah) to store charge. The supplier (Battery Force) was very good and supplied me another sla without any quibble. Here is a guide to SLA batteries :

**LINK**

Occasionally I use a high power resistive load to discharge my 12v sla down to about 1.7v per cell. My charger (Fusion_Elysium_LX60B_Pro) has a discharge/charge cycle capability which is good for my lower capacity batteries (eg NiMH 4.8v 2ah battery for receiver).

I label all my batteries and keep a log book to record the date of recharging.

Ian

[ashley needhamParticipant @ashleyneedham69188]

Cor! a blast from the past (as posts go)…I was so young then!

Despite carping on about homogenisation, things have fallen by the wayside, what with various specials and so forth. The Sunderland, BFB3, BHA, Ecranoplan and carrier all have specific batteries, Nimh or 12v.. I have purchased yet another Voltage Nimh for the current special, and a 12v Nimh to make the Seahawk and Fantome go faster.

Trevor at the pond is standardising on yer common or garden r/c 7.2V Nimh sub C size pack, He is starting from scratch in the boat building world and so he may be making the right decision. However, so far he is building small, and when the time comes and he builds BIG, then he will discover one of the benefits of SLA batteries, the weight is very handy ballast, especially if you are not building fast ones. My carrier has one dead 12V 7Ahr battery, and two similar "live" ones for power.. thats some serious weight, and would be a pain having to find lead or cement/whatever to add simply to ballast, when the batteries do the job nicely.

So saying, my regime, with the SLA types (as per the last post) is NOT to flatten them in the boat, and to recharge ASAP when at home, I have a 2-6-12 charger from MFA and charge them until they JUST start to bubble. The smaller ones are rotated so get a charge every month or so, the 12v ones are out at least once a month(ish) so get their charge similarly. I have indeed written on them as to when they were purchased.

Ashley

[Trevor HollowayParticipant @trevorholloway99134]

Indeed 7.2v sticks are my standard battery and power six of the eight boats I have ranging from 24" tug (with lead ballast in an old 1 pint milk carton for easy removal), 26" MTB, a couple of RTR speed boats, 36" Oil Rig Supply Vessel plus the new "project".

I generally scratch build, some to my own ("make it up as you go along&quot design and to a budget. If I go BIG whatever it will be will just use two sticks.

The battery standardisation allows me to choose what to take and swap between models at the pond side.

[Malcolm FraryParticipant @malcolmfrary95515]

Posted by david the newbe on 01/11/2012 10:40:15:

hi all

i have got a 6v 4.5 ahr sla from maplins can thay be charged with a car charger that has a 6v setting

dave

In a word, no. The car chargers are intended for liquid batteries rather than gel cells (which most SLA are) and are nothing like well mannered enough for the SLA to survive. The chemical changes that happen need to do so in a calm and orderly manner, this just does not happen with a car charger. A "proper" charger will more that pay for itself in the first couple of weeks – you dont have to buy replacement batteries after overcharging. The "S" is for "Sealed". This means "sealed for life", which also means "when it has vented through being overcharged, you can't replace the lost fluid, and its a deader".

Having said that, some smart chargers are too smart for their own good, and fail to recognise a heavily discharged battery, which might benefit from a FEW minutes blast from a rough and ready car charger under close observation of your voltmeter just the restart the forming process.

[david the newbeParticipant @davidthenewbe]

hi and thankyou all ill get a charger for the sla battery

dave

[ashley needhamParticipant @ashleyneedham69188]

Smart chargers,…yes, too clever. I bought some cheap SLA chargers from Maplin, the ones that are just a big square plug with a wire wire off to the battery, and they start flashing (to indicate the battery is full) after a very short time, even on a well used battery (run down that is). This is why a purchased a non-automatic 2-6-12 charger from MFA.

The little plug ones are handy for topping up a battery thgat is on the shelf however, the rapid flashing indicates fullness AND a small trickle charge.

ashley

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