Modern Vespa

Best battery for a 12v converted Rally to run powerful lights, horn etc.

tough to fit into the Rally cage.

Need 12V obviously.

do Amps or AH matter aside from how long they last?

here is a picture to two that I found that can fit into the area. Any opinions?

There is nothing lithium about that battery.

Lol. Nice labeling. Lithium power sport battery brand name. Sealed lead acid product.

really,

interesting

I'm puzzled by the previous comments ...

The first battery is lithium https://x2powerbattery.com/lithium-powersport/

While I can appreciate the discussion on lead vs lithium, it is pretty irrelevant to my question. What I am looking for is a battery that will work well for my 12v conversion of my Rally 200.

I have the Rally style battery holder which limits the size to about 4 inches across. I want something that will fit in there, look decent and work well with some upgraded lights etc.

Anyone who has done this type of conversion, let me know what product specs to look for.

Do AmpH matter? etc.

thanks for the input !!

Last edited by CraigTebeau on Sun May 08, 2022 6:50 pm; edited 1 time in total

My bad. I thought the two photos were of the same battery just back side. Appeared to be contradicting the labelling that said it was lithium.. cause the second photo says sealed lead acid .

There is also this smaller lithium battery that pheasant plucker used on his raw style scoot.

I'm thinking of using it on my small frame cause it's a much smaller battery size.

https://antigravitybatteries.com/products/starter-batteries/small-case/ag-401/

No problem.

Are the ampHrs really that useful if the battery is hooked up to a recharging system like we have?

In other words, what do terms like the cold cranking amps, cranking amps, or watts have to do to our set-ups on these old bikes?

Probably nothing. I just don't want to blow out a bunch of bulbs.

Sorry, can't offer any technical advice. Electrical not my thing. Not even sure that battery I linked would work straight. It might need a special regulator to work in the electrical system on the bike. Not sure. But if you want to read the thread I was referring to:
How to cheat and get a barn find. (Page 11)

A little note, the lithium above is 18 watt hours which equals 1.5 amp hours. So a lot less.

PS, no i don't have any answers for your other questions but i can do maths and spot details

Yeah, I noticed that was less than the typical p200 battery which are 5 Ah so may need more - which is a bit bigger battery.

Also, I am not sure how well they stay charged on the 12v ac to dc charging system. I will likely just go to match the battery Ah with another sealed lead battery, unless someone informs me differently.

I appreciate all the imput, links to videos and that discussion with the awesome upgraded metal scooter. Wild.

Just as a warning, I'd be hesitant to use an Antigravity battery that has a "small case". Their Small Case battery line don't have a built in "battery management system". That means if the batty gets discharged, then it could be permanently damaged (and a voided warranty). It's definitely tempting to go after one of their "small cases", but it would be safer to use one of their batteries that have a "BMS" circuit.

Just how powerful are your lights, horn, ect?

Good point.

Headlamp - 35 w halogen or LED 18 wt 1,5 amp

Tail Lights 10-15 wtts each

speedo light 10 wtts

I am thinking I want to be at at least 8 Amp/H but my need is pretty slight and since these batteries are spendy, the smaller the better.

Edited

Last edited by whodatschrome on Mon May 09, 2022 8:00 pm; edited 2 times in total

The thing I find confusing is that if your battery is connected to a constant re-charging current, in my case I will have about 8.28 amps DC converted from my AC coil output which is connected to my + lead of the battery, thus constantly putting a charge on that system - then that battery's hourly capacity can be dissipated to the same degree 8.28 amps - full 90 watts - and continue to support that without dissipating the battery at all.

So, having an extra capacity, or ampH reading, which tells me how much power this battery will put out before going low, seems almost irrelevant.

Unless you are running your battery powered items without the charging going on constantly, then you really do not need that extra capacity and something like 2 to 4 amp/hour really would be fine.

I am sure I am missing something, so, if you understand this, explain. In any case, I still feel like I will try to get the largest Amph reading that I can cleanly fit into that bracket. I think since I can place it at 90 degrees the Antigravity Battery small case batteries look like they will fit and leave room for the spare.

Have to determine how to make that look retro a bit, or at least not half-assed.

thank you all for your excellent help.

craig

You are mostly correct, if your not running an electric start you really don't need a big battery. If your riding say in town at a lower rpm, stator output is most likely less then 8.28 amps. Is that rating an at idle rating or a say cruising at 5500 rpm rating? Worst case scenario would be running at night with your headlight on stop light to stop light. Will charging system keep up? This is where a battery will even things out and keep headlight on at idle. Little food for thought.

With all that said I have a lithium in mine with stock charging system and it is has a measured 10 amp hour capacity and no starter. Never had any issues, old battery out of my motorcycle. I wouldn't hesitate to buy a smaller battery, if anything I would put in a smaller battery and shed DC load with money saved with led lighting to reduce system load. I've replaced everything except headlight so far.

Off to work my miscellaneous morning ramblings.

I put my battery inside this case (no longer available):
http://www.guzzino.com/baboxb4it.html

There are similar ones out there:
https://www.feked.com/lucas-b49-6-type-battery-box.html
https://www.rexs-speedshop.com/product/genuine-lucas-b49-6-puz5d-rubber-case/

the internal dimensions are 3"x3"x5" so anything that can fit that would work.

this looks like it would fit https://www.batterymart.com/p-sla-1039-12-volt-2-3-ah-sealed-lead-acid-battery.html

Toss anything in there, it's only really acting as a buffer to reduce voltage spikes from the regulator. If you switch to LED that will make things better!

The current you have listed in nothing really.

Edited

Last edited by whodatschrome on Mon May 09, 2022 7:57 pm; edited 1 time in total

The US market '74 rally ran everything but the ignition off the battery. Second only to the GS150 in that regard.

with the original 6V system it was common to need to run without the headlight to be sure you had enough in the battery. But with the vespatronic I think it keeps up just fine. I still turn the headlight off for most day time rides but only out of habit.

Thanks for setting me straight Patrick. I erased two of my replies above so as to not create more confusion.

I had the bike for over 30 years, and as you can tell, I barely know what the hell is going on with the electrics. I will say though, that the people on this forum, are the most helpful people I have ever found on an internet forum. Really invaluable resources. I cannot thank you for the help and patience to help me understand this system so that I can create the solid clean as can be bike I had always wanted when I was younger and could not afford it.

Thanks!