Q Beam MaxMillion II battery

[grayrock]

Looking to replace the battery. This light is decades old. Still works great when plugged in to a 12 V socket. The battery is kaput. Surely since this was made there has been an advance in battery technology. Where can I get a replacement battery for this that fits the case for the original 12 V rechargeable SLA cell. The one that came out is marked HK-6FM2.8X. It has side terminals. Does anyone make an equivalent sized battery that has more than 2.8Ah? Thanks in advance for any assistance you may provide.

 

[A_L_R_O_M]

Well you should build your own battery with 18650 or 21700 cells 3 in series.
You can even try to do it without bms plate, just a little overvoltage should help

 

[grayrock]

Thanks for the suggestion- but that is outside of my comfort zone. I disassembled the battery pack and can find a replacement for the SLA, just wanted to see if anyone knew a cheaper place to purchase one and if there was one with a higher Ah rating that was the same size. Surely there is a higher capacity battery available somewhere, considering how old this is. Has modern technology not augmented the SLA industry?

 

[A_L_R_O_M]

Lithium cells performs much better than SLA but compared to ni-mh technology it's not that much. And you can use ni-mh cells without bms plate

 

[electromage]

I'd be interested to see how that light performs with a lithium battery.

That's probably a 55W halogen bulb, which means it only draws around 4.5A. Most 18650s can supply this easily, and 3S will provide around the correct voltage, without going too high for the bulb. The voltage drop from the original battery was probably bad, and you'll likely get better performance across the life of the battery.

If you used 3S 21700 like Molicel INR-21700-M50A, you'd at least double the original runtime, I say at least because SLA battery capacity drops quite a bit at higher currents. I'd guess at 2C you're close to halving the real capacity of the cell, making that effectively a 1.4AH, and giving you about 15 minutes of runtime. Am I close? You'll get probably an hour on 5AH 21700s.

If you're not comfortable making your own pack, you're going to pay quite a bit more but BioEnno might be a good place to start: https://www.bioennopower.com/collections/12v-series-lifepo4-batteries Compare your dimensions, and find one that will fit. Keep in mind that whether you go with LiIon or LiFePO4, you will need a specific charger for it, don't try to charge it using the light's built-in charger. I'd remove it to be safe.

 

[BVH]

To get the most out of the incan lamp, use a 4S LiFePo4. It will settle to about 13.8 Volts a few hours after charging and will hold about 13.4 under load. Any 12V halogen lamp will be fine at 14.4 Volts. A 3S LiIon will almost immediately fall to 12.3 or so when the light is turned on and plummet from there.

 

[grayrock]

OK- it's been about 3 ½ years. Any advances? How about sources for my quest? I'm not a builder and I am often too frugal for my needs. Anything new in the marketplace that would help me accomplish my goal?

 

[Lips]

I redid two batteries back in November for a dead light. Pretty easy and just put new battery back like it came out. There is enough room to do it. I did have to soldier a little. Bought two cheap batteries like what was inside...

 

[grayrock]

Looks like yours is a 6V. Mine is 12 V. I can find a direct replacement for mine, but was hoping to get better run times. How does yours work with the new batteries?

 

[Lips]

Looks like yours is a 6V. Mine is 12 V. I can find a direct replacement for mine, but was hoping to get better run times. How does yours work with the new batteries?

You probably could hunt up a Lifepo4 or Lithium battery pack (with balance) with more capacity that would fit inside the box. Then get a cheap charger and use that to charge it up with the cut and modified original plug-in. Probably more trouble than it's worth. Simpler to get the same type battery and change it out...



I had two batteries and changed both out for $10 each. Mine works like a new one now with two batteries. Lipo etc would likely work and not flash that 12v bulb but you'd have to spend $'s to get a charger and scavenge the plug to make it work.