Can my makita bl1830 battery
This battery has a known design defect that causes premature failure. The battery is still probably good, but the safety circuit n the battery spuriously locks it, due to a bug. Once locked, it won't charge in the Makita charger (flashing red and green lights). Makita knows about this problem but so far is not actively recalling the batteries. Makita will replace the pack if the charge count is under 150 (some people say 300?) regardless of warranty status, but you have to take or mail it to a Makita Service Center -- the dealers won't handle this unless it's in warranty.
If Makita won't fix it, you can try to repair it. If the red and green lights are flashing, the battery is probably locked and cannot be repaired in a way that will let it be charged in the Makita charger (but it can be charged in off brand chargers). Buy a clone charger on eBay for $60 and try it. If it charges, just use it, no repair needed.
Be aware that lithium batteries do lose capacity permanently at a rate
of about 20% per year. So, 3-6 years is about the best battery life you
can expect - from date of manufacture, so if it sat in the store a
while that adds. Makita derates the cells to allow for some shelf life
(down from 2400 Mah to 1500 Mah rating).
If the battery is weak, and only gives brief usage, you can replace some of or all of the cells in the battery. These are expensive and worth repairing. See this video:
If just 1 or 2 cells are weak, you can replace them with the same Sony 18650 size 2400 Mah capacity battery, green sleeve. The Sony's are not sold retail, and are hard to find other than from another Makita pack or from some laptop packs. If more are weak, you're better off just replacing all of them with new 18650 2400 Mah (or higher) batteries with tabs. Look for Tenergy or other quality brand.
Hope that helps.
Makita 2 Bl1830...
on Sep 20, 2014