Which Battery?

[Peter Cooke]

Hi folks,


I'm almost finished my H-D 31V and need to get a battery. As I'm restoring it I've got one of those gutted resin copies of an original battery so am looking for something that'll fit inside which pretty much narrows the field to Lithium batteries. The one shown at the link below is what I'm considering and I can get from the local "motorcycle stuff" chain store which is a bonus. What I'm not sure about is the amp hour rating which seems quite low at 2.4 but may not be an issue given the gen is converted to 2 brush, with an electronic regulator, and the head & tail lights have been converted to LED.
I noticed at the bottom of the page it says "replaces B38-6A" which I think is a commonly used 6v battery in old bikes so it may be ok.

SSB LFP612L UltraLite Lithium Motorcycle Battery | Batteries Direct

My other option is to use a sealed AGM as per below which at 20 amp hour seems more than up to the task. It won't fit in the resin case but it's height would make it suitable that I can use the resin lid with it so I'd still have the original looking terminals poking out of the battery box.

Power-Sonic PS Series Battery PS 6 volt 20 ah PS6200

Member 'PRG' (Peter from The Ozarks) gave this advice back in 2020 which suggests that a Lithium should work just fine assuming the 2.4 amp hour rate is enough.

"Search 32E two brush conversion, V Tronic electronic regulator and Shorai lithium iron
battery on this and Classic American Iron’s forum and you’ll likely find your answer. I
discarded that mechanical cutout and lead acid battery 9 years ago and have had
thousands of carefree miles in all conditions since, never on a charger. The latest
insurance to load reduction has been converting this machine entirely to LED’s enabling
running headlight and spots with impunity in low rpm stop and go riding".


Peter mentions Shorai Lithium Iron. I did find one (LFX18A2-BS06) that'd fit and is 18 amp hour but can't get it here in Oz.

I'm getting way out of my swim lane with the whole 'which battery' stuff so would appreciate any useful info anyone cares to share!

Thanks folks.
Peter

[Steve Slocombe]

Dear Peter, I've used a lot of B38-6A batteries, which fit the VL case nicely if left in their cardboard box, and add terminal cheaters if the bike is going in for AMCA judging. The VL is relatively unusual because so little of the battery is visible compared with Indians and Brit bikes. With what you have and LED lighting I'd use the small local battery in the repro case.

[Tom Wilcock]

Because of lithium-ion batterys bad record of starting fires I stay away from them. I use sealed lead acid batteries.
Tom

[Skirted]

Been using the Shorai BS06 for around 13 years in various 6 volt applications. Peter "PRG" was the one who recommended Shorai. Awesome battery but MUST make sure your electronic regulator doesn't exceed 7.2 volts. This is why they should never be used with a 3 brush generator. My personal experience has been they like a steady 7.1-7.2 volts charging rate. I never fuss putting a battery tender on any of them during winter season which can be as long as 5 months. Voltage stays stable and bikes fire right up in spring. My oldest BS06 lasted 11 years and was on a bike that saw a lot of use.

[joe fxs fxr]

My experience with a lithium battery has been with an AntiGravity in my chopper. It's an EVO motor and charging system, and that's the key. As Skirted says.high charging voltage will cook them, and cause fires. You DON"T NEED a tender with a lithium battery - just disconnect it during winter storage. In the spring, wake it up by turning on the headlight for 30 seconds three times. Then it's ready to fire up the bike. This spring will start the fourth season with that battery. Previous AGM batteries never lasted two whole seasons because the battery is in the oil tank.

[otis71]

I use the sealed AGM batteries designed for alarms and emergency lights. Available in 12 and 6v. They last forever and seldomly need a charge. Two smaller ones wired in parallel generally gives more amperage and usually a better fit. Only downside is they give little notice when they go bad but if running two you always have a backup. Available everywhere and ridiculously cheap.