12v Battery purchase

12v

(osbrook) #21

I think it can go up to 25Amp but that sounds a bit high for such a small battery. Perhaps that is why so many expand.

In fact you can see this in the other thread about charges. Look at the pictures. :slight_smile:


(m1n1s) #22

Yes depends on your charger model early ones [email protected] later ones [email protected]

This will fry the Li-PO , actually it will probably burst into flames…


Can the 12V battery work as power supply?
(askho) #23

@Silas
After drilling the terminals did you bend them so they are standing upright like the original so that you can connect to the leads? Thanks


(askho) #24

@mikeburles.
Same question as above. Did you bend the terminals upright to connect the terminal cables?


(michael burles) #25

Yes i did bend the terminals and then drilled small holes and used self tapping screws to secure the terminals. Be careful because the terminals are very small so use a small drill and put washers on the screws to secure terminals. Twizy been fine since new battery fitted.


(askho) #26

@mikeburles
Thanks. I have just ordered a battery and I will do the same.


(John Wilson) #27

I’ll just get the Original then. I suspect that the 12v system doesn’t put all that through the battery unless it has to, i.e. when the system is under full load. All lights on, window heater on brake lights etc, but it’s probably going out at the same time.


(osbrook) #28

I suspect you have that the wrong way round. 25amp or 27amp into a small 12V battery will cause it to swell and over heat. Damaging it.

25/27AMP out would kill the battery very quickly and cause the DC-DC charger to cut in and help out.

But either way a Li battery is not a direct replacement.


(John Wilson) #29

No I don’t think I have, if everything is on the load on the system would be about 250W, which is about 250/12 = 20.83a So if the battery was left to do that without an assistance, yep it would go flat pretty quick, so I would assume the system just tops the battery up with what it actually needs to keep the voltage up. So that would be up to 4.2A as required by system load. That would be about the same as a normal battery charger (approx) would throw at it.

As an aside when I turn my Twizy on with the Power box connected it shows current from the main battery of up to 7 amps with the lights on, so it’s using 336 watts based on a nominal 48Vs from the Twizy battery, so the 25-27 A would look to be what’s needed at 12v just to keep up.

Like I said, I’ll be sticking with the Lead Acid Battery.


(alex) #30

I don’t get why the lead acid can’t be replaced with something ultralight :confused:
I don’t know the weight but whichever weight reduction would increase acceleration and milage a bit … Please somebody find a way out! :grinning:


(osbrook) #31

I thought we had explained. The light weight batteries need a different charger, which makes it a bit more complex. I can be done but…

Some Car battery sized 12V batteries come with the BMS built in and are a direct replacement. The high energy density of the Li?? batteries mean there is room in the same sized battery case to fit the electronics.

To diy you need to ensure that power to the Twizy comes directly form the Battery ie. big Diode in line. While the power from the Twizy to the battery goes via a new charger. There are 12V to 12V Lithium battery charges that would do this job. Not cheap in comparison with a straight swap. As the Twizy 12V battery is small by the time you have added the extra charging circuit you may not save any weight :frowning:

Remove weight else where ie. remove the charging cable - making it detachable like the big EV’s. Empty the windscreen washer bottle, at least reduce it’s size. Take the speaker cowling out and speaker supports., Room the glove box lids. Any of which will save more weight that the battery swap.


(michael burles) #32

My heavy duty golf buggy battery has been on my Twizy for a couple of weeks now and has started every time. Done a few local trips but have not needed to charge it since new battery fitted. I want to see how long it lasts.


(George Boon) #33

Hi, which battery did you order, and is it now working fine?


(osbrook) #34

This is the correct spec but not sure of terminal connections.


(George Boon) #35

hi,

i’ve just ordered this battery. Is it difficult to fit?


(osbrook) #36

Just need to adapt the terminals. Make your own F-spade to bolt hole adaptors and then should be an easy fit. But not done it on a Twizy so don’t know the fine details only the Theory and experience with other batteries.


(askho) #37

@George_Boon
Just bought one off eBay. It’s a Strident AGM GP12-14. Basically I looked for one that is 12v 14Ah and with similar dimensions to the original. It came with different terminals. The original has got quite wide upright terminals with a hole in them so the connectors screw through the holes. The Strident one, as with most after market ones, comes with spade terminals. I had to bend them upright (as original), drilled holes through them so the original connectors will go through. A quite delicate job, but even I managed it, so most people can. Worked perfectly since.


(askho) #38

@George_Boon
Just noticed you’ve bought the Yuasa battery. That has got the same spade terminals as the Strident one I bought. If you can get spade connectors like the ones @m1n1s got ( 3rd post on this thread) then you don’t need to drill the terminals. I tried but without success. So eventually I drilled the terminals because I wanted to use the original connectors.
Good luck. Let us know how you got on.


(m1n1s) #39

The piggy back connectors I used are from a mini starter solenoid, these should be available to buy from your local car parts store or online from a mini part specialist.

I had these laying around my garage, the piggy backs where fitted standing up, terminals were greased to protect from water ingress and then bound in electrical tape.

Recently I have checked the setup after six months and everything is still in good serviceable condition.


#40

I know that this an old post, but did not think it was worth generating a new topic.

I think that I have found the best solution. I sourced this at my local specialist battery dealer:

The serial no. is EK143; price £48.00. It is also available online in the U.K. at thebatteryshop.co.uk. Terminals are pre-drilled.


Thinking about a Twizy