EBL 26650 LiIon Protection Circuit problem on Heng Long tank

[keilau]

I bought 4 more EBL 26650 to make 2 more packs. The cost including hardware is about $12 per pack which is an excellent value. The EBL cells are rated 5000 mAh per cell which is the correct rating when charged to 4.2 volts or more. My SkyRC B6 charge programs the 2S Li-Ion to charge to only 8.2 volts for longer battery life, thus the 4500 mAh, which is a prudent recommendation.

High quality Japanese/Taiwanese 18650 Li-Ion cell (3000 mAh or higher) all but disappeared from the retail market. Cheap Chinese 18650 often rates itself 9000 mAh or higher, but struggles to hold 900 mAh.

I just received my newly purchased Heng Long Sherman (3898-1), and was pleasantly surprised that HL switched to XT-60 power plug. The tank comes with a dual 18650 battery pak that holds 1100 mAh when charged to 8.2 volts. In early HL days in 2000's, this will be called premium battery, Haha.

I have long been a fan of EBL Lithium Ion battery for their best value and honest capacity rating. They are low drain battery with discharge rated at 0.2C standard and 1.0C max. On paper, it should have enough margin to run Heng Long RC tank with 380/390 series motors. Since early 2021, I made several 2S 26650 packs and use them successfully on HL tanks. Though in the back of my mind, I have concern that whether the EBL is useful in battle on rough terrain.

I purchased a new batch of EBL 26650 batteries and made a new 2S pack for the HL Sherman. I recently finished the metal upgrade of the Sherman and started testing it on my 2x4 dynamo. To my surprise and disappointment, the Sherman shut down completely after I ran it at top speed for a few minutes. After some evaluation by substitution, I identified the problem to the internal protection circuit of the new batch of 26650. The new 26650 pack will recover overnight and test perfectly on my B6 intelligent charger.

I equiped the HL Sherman with Mato T74 metal track with duckbills. It is probably one of the heaviest metal track for the Sherman. For now, I am using a 2S2P 18650 LiIon pack with the Sherman with no problems.

[keilau]

I have long been a fan of EBL Lithium Ion battery for their best value and honest capacity rating. They are low drain battery with discharge rated at 0.2C standard and 1.0C max. On paper, it should have enough margin to run Heng Long RC tank with 380/390 series motors. Since early 2021, I made several 2S 26650 packs and use them successfully on HL tanks. Though in the back of my mind, I have concern that whether the EBL is useful in battle on rough terrain.

I purchased a new batch of EBL 26650 batteries and made a new 2S pack for the HL Sherman. I recently finished the metal upgrade of the Sherman and started testing it on my 2x4 dynamo. To my surprise and disappointment, the Sherman shut down completely after I ran it at top speed for a few minutes. After some evaluation by substitution, I identified the problem to the internal protection circuit of the new batch of 26650. The new 26650 pack will recover overnight and test perfectly on my B6 intelligent charger.

I equiped the HL Sherman with Mato T74 metal track with duckbills. It is probably one of the heaviest metal track for the Sherman. For now, I am using a 2S2P 18650 LiIon pack with the Sherman with no problems.

I made a major mess up with my first post. The pack that shuts down is NOT the EBL26650. It was the KeepPower26650 pack. The KeepPower26650 cell is rated for a high discharge current of 15A. I suspect that they are designed for resistive loads only, such as vaping or high lumen latern. The inductive load of the Tamiya 380 motor tripped up its protection circuit.

I paid twice the price (vs. EBL) for the KeepPower cells and they turn out to be lemon for driving small motors.