Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: gwa84the2nd on July 09, 2012, 11:38:00 pm
-
hi ime aftter changing 2 12v 12amp sla baterys for the aquivelent lipo but numbers are confusing me lol what wuld be the equivelent its not boat related as its for an electric scooter so loosing the pounds wont be a poblem
-
use two 3s 11.1v 6000mah with both with 25C discharge rate. hook them up in parallel and use 2 low voltage alarms
-
12 AH is the equivalent of 12000 mAH, the closest Lipo is 11.1 volt or 3S but remember a fully charged Li-po is 12.6 volts, this drops to approximately 11.1 under load, similar to a gel cell., you could go to a 14.4 4S with the risk of blowing electrics but the extra speed is a bonus
Be careful of the connection format of the batteries, you could have the two 12v batteries connected in series or parallel , if you put the new batteries in differently it could end in <:(
Mad Mike has given a direct equivalent for a parallel set-up but only 1/2 the capacity, If the batteries are in parallel you would need 4 6000 mAH 11.1 all connected in parallel, if its a series set-up two 6000 6S 22.2Volt Li-po in parallel will give you eq.
A Lipo is smaller per mAH, so a larger capacity Lipo can be used and take up the same space ok2
Nick
-
Be warned tho 6S 6000Mah Lipos are not cheap! (not half decent ones anyways)
-
Are we talking about a 24V scooter with one drive motor, a 12V Scooter with 1 drive motor or a joystick controlled
scooter with two motors @ 12 volts, one on each drive wheel providing steering ?
Three different battery set ups.
A tad expensive methinks.
Ned
-
thanks for the advice peeps the scoot runs on 22volts so its in searise ? just looking at the pice of the batts yeha thats gonna heart the wallet lol might just have to replace the sla's thout going to lipo woud work out abit cheeper as i can only fined sla'a of 12v 12a that are very expencive and geting them deliverd is even worse the scoot is for my mother ho's disabled she relies on it to get her around a bit more aficiantly then walking but monny beeing tight as it is then ill have to keep looking for some cheep batts
thanks james :-))
-
Another thing to bear in mind is the stability of lipos.... I wouldnt want to be sitting on that many large lipos
-
http://www.component-shop.co.uk/html/lead-acid.html
These guys are the business.
£2.95 delivery for the pair.
Ned
-
cool thanks for that link ive used them befour but dident relise it whas so cheep for sla dilivery :-))
-
Although this isn't about model boats, I have allowed it on the grounds that it is Battery technology information which is helpful to us all.
ken
-
ohh crykey ive been blue penceld lol :}
cheers Kenny :-))
-
Charging would also be an issue - it would probably not be as simple as plug-it-in. I would certainly not expect the charger provided with the scooter to work at all safely.
And I'm really struggling not to make comment about the comment about stability of LiPo's...
-
Charging would also be an issue - it would probably not be as simple as plug-it-in. I would certainly not expect the charger provided with the scooter to work at all safely.
And I'm really struggling not to make comment about the comment about stability of LiPo's...
Another thing to bear in mind is the stability of lipos.... I wouldnt want to be sitting on that many large lipos
See above :)
-
12 AH is the equivalent of 12000 mAH, the closest Lipo is 11.1 volt or 3S but remember a fully charged Li-po is 12.6 volts, this drops to approximately 11.1 under load, similar to a gel cell., you could go to a 14.4 4S with the risk of blowing electrics but the extra speed is a bonus
Be careful of the connection format of the batteries, you could have the two 12v batteries connected in series or parallel , if you put the new batteries in differently it could end in <:(
Mad Mike has given a direct equivalent for a parallel set-up but only 1/2 the capacity, If the batteries are in parallel you would need 4 6000 mAH 11.1 all connected in parallel, if its a series set-up two 6000 6S 22.2Volt Li-po in parallel will give you eq.
A Lipo is smaller per mAH, so a larger capacity Lipo can be used and take up the same space ok2
Nick
Ive only just noticed that the request for two 12v 12ah slas. yes my battery combo would give you 12ah but 12 volts, not 12ah 24 volts. Also as nick has mentioned lipos are smaller than thier sla counterparts. in by fact by a 3rd at least. For example if the scooter or boat had a well in it that could allow the room for a 12v 6ah battery, in that same space you could fit three 12 6ah lipos, hook them up in parallel and you got 12v 18ah. For a mobility scooter that additional distance would be very useful and for boats thats a weeks sailing.
-
Not recommending these people in particular, they are just someone that popped up in a Google search, do a search for LiFeP04
http://www.pingbattery.com/servlet/the-24V-LiFePO4-Battery-Packs/Categories
This style is more user friendly for your application, packs built like this have the balancing and LV cut out circuitry built in the battery, the charger is relatively cheap.
Nick
-
With lipos you would need battery monitoring to prevent over discharging the batterys. Yes if things do short out then Lipos can be fun. John.
-
nick they would be briliant but the price s astranomical lol way out of mine and me mother budget but somthing to look at in the future when hopfully the price of the baterys comes dawn
thanks agean for all the input peeps much apresiated :-))