Soldato
- Joined
- 4 Aug 2007
- Posts
- 22,414
- Location
- Wilds of suffolk
I have a water butt pump that i use at the allotment.
Something has gone wrong with the battery it would seem, wont charge, or some part of the battery unit.
I pulled the unit to bits to take a check if any obvious loose wire and no.
Even worse is that a significant chunk of the electrics are sealed into a section with resin.
The battery "unit" has 3x 3.7v batteries, a small circuit board that I think probably covers charging, a variable rotating switch (to affect pump speed) and a highly waterproof connector plug to join to the pump unit itself.
So with this borked, somehow I need to test to confirm the pump itself is still fine and if so sort a solution.
Draper made the unit but its delisted.
I have a cunning plan, kind of, that over a few steps could work out ok, at least I think so.
The original is iirc 2AH, so I need 2-3AH of capcaity. It needs to be easily portable so I can take it backwards and forwards from the allotment daily. As such I came across scooter batteries, these are listed as 12v and 3AH is a small pack around the size of a tub of butter.
This would meet the main criteria.
Obviously I would need a trickle charger to top it back up. Thats also easy to get and not too expensive.
So I need to know, are 12v scooter batteries really 12v, or are they just scaled down 14.4v car batteries.
If they are genuinely 12v then I could use one of these.
I would need to : waterproof it, although I could position it a decent distance from the water tank the pump itself is put into (pump itself has about 2M of cable and it only drops about 50cm in. Plus as i would need to either change the connectors for both ends, or at least make a connector to the battery, I could add another couple of metres there. Waterproofing wouldn't need to be more than splash proofing really so thats not hard to achieve, Plus a connector, this would need to suit the charger also. It cannot be fully sealed as the scooter batteries need to vent to air.
If this worked i would need to add the potential for a voltage dropper, of somekind. The pump itself has a float switch in it, so if it draws water too fast the tank would run dry and the pump would stop itself. That could come later if the whole process works.
The other option is to replicates similar with 3.7v batteries. They look like bigger AAs, about 50% bigger.
I would need to overcome all the same issues, storage, charging, and voltage regulation.
Anyone got any suggestions?
The old tech lead acid is more appealing as for less than £20 I can get a 7Ah or so, and that would probably provide over an hour of watering. Which would be more than enough! A trickle charger for £10 or so and all i need to worry about it connectors etc (it deffo only supplies pos and neg to the pump itself, although there are loads of wires in the battery pack unit as its also a charger built in
Something has gone wrong with the battery it would seem, wont charge, or some part of the battery unit.
I pulled the unit to bits to take a check if any obvious loose wire and no.
Even worse is that a significant chunk of the electrics are sealed into a section with resin.
The battery "unit" has 3x 3.7v batteries, a small circuit board that I think probably covers charging, a variable rotating switch (to affect pump speed) and a highly waterproof connector plug to join to the pump unit itself.
So with this borked, somehow I need to test to confirm the pump itself is still fine and if so sort a solution.
Draper made the unit but its delisted.
I have a cunning plan, kind of, that over a few steps could work out ok, at least I think so.
The original is iirc 2AH, so I need 2-3AH of capcaity. It needs to be easily portable so I can take it backwards and forwards from the allotment daily. As such I came across scooter batteries, these are listed as 12v and 3AH is a small pack around the size of a tub of butter.
This would meet the main criteria.
Obviously I would need a trickle charger to top it back up. Thats also easy to get and not too expensive.
So I need to know, are 12v scooter batteries really 12v, or are they just scaled down 14.4v car batteries.
If they are genuinely 12v then I could use one of these.
I would need to : waterproof it, although I could position it a decent distance from the water tank the pump itself is put into (pump itself has about 2M of cable and it only drops about 50cm in. Plus as i would need to either change the connectors for both ends, or at least make a connector to the battery, I could add another couple of metres there. Waterproofing wouldn't need to be more than splash proofing really so thats not hard to achieve, Plus a connector, this would need to suit the charger also. It cannot be fully sealed as the scooter batteries need to vent to air.
If this worked i would need to add the potential for a voltage dropper, of somekind. The pump itself has a float switch in it, so if it draws water too fast the tank would run dry and the pump would stop itself. That could come later if the whole process works.
The other option is to replicates similar with 3.7v batteries. They look like bigger AAs, about 50% bigger.
I would need to overcome all the same issues, storage, charging, and voltage regulation.
Anyone got any suggestions?
The old tech lead acid is more appealing as for less than £20 I can get a 7Ah or so, and that would probably provide over an hour of watering. Which would be more than enough! A trickle charger for £10 or so and all i need to worry about it connectors etc (it deffo only supplies pos and neg to the pump itself, although there are loads of wires in the battery pack unit as its also a charger built in
