Club 80-90 Forums

i just got a 15 amp 12v power supply fro shebay and was wondering how i could wire it in.is it ok for it to be on and in line with the l/b and the charger or do i have to isolate them from the powerpack when im using it ? its mainly to run the fridge when hooked up and i know these draw around 6 amps so it should be ok to run other tuff too..but i dunno if it will do anything to it or the l/b if they are all conected together...proberbly sounds a bit daft but there you go
cheers..dave

is it a stupid question ????

weldore wrote:is it a stupid question ????

It is if your fridge works off 240v.............

On 12v your fridge will draw 8 - 9 amps. I would advise against having any connection between your leisure battery and your fridge. In theory, the charger should have enough 'oumph' to run the fridge and other stuff and if connected to the leisure battery should charge that too. Whether a bit of kit designed to charge stuff will enjoy running stuff I don't know. I don't see why you're going to all this trouble though...........

the fridge is 12v and gas only.i was just wondering if i turned on the power supply with it running into the l/b circuit wether or not it would do any damage to the battery or the power pack...if the battery would draw the whole amps from the powerpack if it was low and makeit run hot...praps im wrong....but im not gonna do anything till i know itll be fine

A fridge and a flat battery may very well prove too much for it. I believe some battery chargers output 'pulses' rather than a continuous current so it may not like the fridge anyhow. I personally would run the fridge off the gas - they only use a very small amount of gas anyway.

well i managed to get the psu for 20 quid including postage ,which i thought was a bargain as i know how much these things can be(thats if it works )..i guess your right about the gas thing...i might have been being a bit of a skin flint there
its amazing what you buy on ebay after a few beverages tho

it is a psu...this is different from a charger ??? right???

Hi, yes a PSU is a completely different animal from a battery charger, A PSU will deliver the rated output, all the time. Main problem is heat a 15amp 12v power supply will generate a lot of heat, and this will need to be dissapated. heat is the main killer of power supplies. Hope this helps.

Regards, Graham

cheers graham..wot ill do is test the psu for a few hours when i get it and see if it is suitable for in the van,if it gets too hot then itll be a 12v supply for me to keep to test stuff on .
i thought that the zig units had these built in and it would work the same as them if i wired it in right but i dont want the battery to suck the life out of it or the other way round so maybe if i do use it ill have to have a switch to knock the charger and leisure battery off the 12v circuit for the lights/accessorys and fridge

weldore wrote:it is a psu...this is different from a charger ??? right???

Sorry, I thought you meant a charger......

ok..so i had a chat to the sparky at work today and he tells me a 12v power supply should never be joined to a battery and should be isolated....so thats that then
thanks everyone

right chaps.chapesses....ive recieved the psu today.didnt get a manual but ive found one for it on the net,what i want to know is can this replace my charger and act as a power supply too.ive read the manual and it says this...

The T807/808 is a heavy duty, lightweight switching power supply capable of supplying
up to 15A (T807) or 25A (T808) at 11 to 14V DC. The units require a mains supply of
230V/50Hz or 115V/60Hz (nominal values) which can be internally selected with a
switch (if fitted) or wire links. Remote sensing of the output voltage is available as a
standard feature: if connected, it will ensure that the output voltage remains within
±1% of the preset level from no-load to the full specified load, over the specified mains
voltage and temperature ranges (refer to Section 7.6).
The T807/808 power supply is designed to power T800 series base stations. Specifically,
the T807 will power 50W base stations, while the T808 will provide the current requirements
for 100W base stations.
Electromagnetic compatibility (EMC) and operator safety are both important and critical
parameters for the trouble free functioning of a switching power supply. Refer to
Section 1.2.3 (EMC) and Section 1.2.4 (safety) for current specifications.
The T807/808 is protected against damage caused by faults in the line or load, or by
temperature variations (refer to Section 1.2 for specifications). The protection features
include:
mains transient suppression
mains inrush current limiting
mains undervoltage lockout
soft start
output current limiting
output voltage limiting
output reverse polarity protection
overtemperature shutdown.
The output voltage and current limit and overvoltage points are all adjustable and are
preset during manufacture.
Note: On earlier model power supplies with an issue 03 PCB, the overvoltage
point is not adjustable.
The T807/808 can be used to float charge a 12V battery under constant voltage conditions.
The current limit circuit prevents the charging current from being excessive if the
battery is completely discharged, and the internal rectifier diode will blow the external
fuse in the event of the battery being accidentally connected in reverse. (refer to Section
7.5). An alarm output provides a logic 0 (0V) in the case of a mains and/or power supply
failure, even if a battery is connected to the 13.8V output.
Note: On issue 03, a transient suppression diode across the power supply output
prevents any damage if the battery is accidentally connected in reverse.
A T807/808 may be housed together with other Tait fixed equipment modules in a
standard 484mm (19") rack frame, where it occupies the space of one standard 60mm
module, to give an attractive and convenient installation.

it looks to me like it could be ok but i need a second/third or even forth opinion as im not keyed up with this sort of thing...i have the link to the service manual if you are interested too...oh and the one i have got is the T807..the 15 amp one.
cheers again..dave

Well it's a power supply so ok for fridge. It also says it will charge a battery. I can't see why it wouldn't work both provided the battery wasn't discharged too much.

My tuppence...............

...cheers 1664...i think im just gonna try it and see..keep me eye on it over a few hours on sunday..have a few cans,as you do..then maybe the impending fire wont seem so bad


i think it should be ok

Hi, be careful with that power supply, it sounds like a tait power supply. the base station is for RF comms and the internal battery is probably a Ni-Cd or Lithium-Iron. These charge differently to Lead Acid batteris. Hope the experiment works.

Regards, Graham