# MB battery rebuild help



## Staggrlee (Dec 29, 2014)

1st post, forgive me if this has been covered in previous posts, I can't find much with Search...

I recently picked up a 1st-gen MB (circa '98) and both batteries are shot. I've gotten one of the carcasses open and plan to use a LiFePO4 26650 from BatterySpace.

Has anyone posted a tutorial on doing this? I found a thread by ma_sha1 -- but all the image links are invalid.

I assume I just hook up the leads according to polarity, I don't need the diode that prevents the bottom contacts from draining the battery, and can just cut the cigarette lighter off the 12V coiled cord and wire that up to the LeFePO4 smart charger? 

[h=1]Thanks![/h]


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## BVH (Dec 29, 2014)

You pretty much have it. Use a 4S, 26650 pack with as many Parallel sets as will fit to keep your under pack 14.4 Volts (once they've rested a few minutes). You've probably already seen that they run two parallel + and two parallel - wires for power. No diode needed and cut the cord as you say.


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## Staggrlee (Dec 29, 2014)

Thanks BVH. That's what I'll use then.

Can somebody help perhaps by identifying the component I've highlighted below? It is labeled 400+060f. Is it a 60C thermistor? Should I re-use with the LiFePO4 pack or purchase a new one? If new, is there a different value for the thermistor cutout recommended for the different battery type?


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## FRITZHID (Dec 30, 2014)

It's an unnecessary device used to regulate the charging/discharging of the stock battery.
Being as old as your mb is, you may have issues at 14.4v. I have one newer and one older Gen2 mb and the newer one runs fine on my lipo pack, the other doesn't..... so make sure it will accept the new pack voltage before enclosing.


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## BVH (Dec 30, 2014)

I don't know what you'll spend on materials for the rebuild but you can get this new and unused Nicad on Ebay for about $250 shipped.

http://www.ebay.com/itm/New-Peak-Be...9412135?pt=US_Flashlights&hash=item4d2abb7d27


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## FRITZHID (Dec 30, 2014)

I believe that same person rebuilds packs (or at least I know someone on eBay does), I think it was around $100 iirc but you need to send the dead pack in.


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## Staggrlee (Dec 30, 2014)

Thanks for the suggestion, I saw the eBay postings for the NiCd pack and ones rebuilt with NiMH but on the one hand I have no idea how old the NiCd is, and on the other would need a new charger for NiMH pack anyway.

I ordered the 8-cell LiPo and charger for $150 and will give it a try. I fear Fritz might be right about that not working with my vintage light. It will fire on the fully charged NiCD pack but only lasts about 10min, and won't fire at all on the cigarette lighter adapter with a running vehicle or jumper battery. Did the older lights require higher voltage or is that a function of an aging ballast/igniter? It did come with a new spare lamp I can try.

I've been in touch with Peak Beam and upgrades get spendy quick. I don't want to go too deep into this light considering I picked it up at a thrift store for $50.

I saw that PB lists a new shorter cord for their lipo packs as required. Is this the same connector/pinout on the battery side as the NiCd packs? Is there a significant voltage drop across the longer coiled cord?

Ideally I want to use the light for a 4x4 camping rig and to use lipo so that I can charge directly off the truck alternator with an isolator. Lots of motorcycle guys swear by SLA bulk chargers/alternator charging for lipo batteries and in theory you can get a 95% charge using just constant current charging with a 13.8V float that way. I do have an inverter in the truck but hate running it due to how inefficient it is.


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## FRITZHID (Dec 30, 2014)

Hmmm....it's odd that it won't fire on cig adapter.... not a good sign.


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## Staggrlee (Dec 30, 2014)

I've measured 14.2V on the lamp/lighter cord (lamp end) when connected to a running vehicle and 13.1V on a jumper battery. The cigarette lighter socket in the vehicle is a dedicated run to subfuse panel and has 12ga runs with a 10A fuse. The 10A fuse is not blowing and I can hear the click as it tries to fire. May as well try the spare lamp.


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## Staggrlee (Dec 30, 2014)

Not the lamp...


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## RT84 (Jun 23, 2017)

Hello, first post, but long time reader. I have a MB battery i am trying to rebuild but having trouble getting it apart is there a easy way to get them open. Thanks.


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